better comment

* Guarantee a unique name for the constants that represent enum values

* update samples

* Use all-caps

CI/samples.ci/client/petstore/java/test-manual/okhttp-gson/model/ArrayOfArrayOfNumberOnlyTest.java

@@ -53,6 +53,7 @@ public class ArrayOfArrayOfNumberOnlyTest {
         List<BigDecimal> arrayArrayNumber = new ArrayList<BigDecimal>();
         arrayArrayNumber.add(b1);
         arrayArrayNumber.add(b2);
+        model.setArrayArrayNumber(new ArrayList<List<BigDecimal>>());
         model.getArrayArrayNumber().add(arrayArrayNumber);
 
         // create another instance for comparison
@@ -62,6 +63,7 @@ public class ArrayOfArrayOfNumberOnlyTest {
         List<BigDecimal> arrayArrayNumber2 = new ArrayList<BigDecimal>();
         arrayArrayNumber2.add(b1);
         arrayArrayNumber2.add(b2);
+        model2.setArrayArrayNumber(new ArrayList<List<BigDecimal>>());
         model2.getArrayArrayNumber().add(arrayArrayNumber2);
 
         Assert.assertTrue(model2.equals(model));

README.md

@@ -8,6 +8,12 @@
 [![Windows Test](https://ci.appveyor.com/api/projects/status/github/openapitools/openapi-generator?branch=master&svg=true&passingText=Windows%20Test%20-%20OK&failingText=Windows%20Test%20-%20Fails)](https://ci.appveyor.com/project/WilliamCheng/openapi-generator-wh2wu)
 [![JDK11 Build](https://cloud.drone.io/api/badges/OpenAPITools/openapi-generator/status.svg?ref=refs/heads/master)](https://cloud.drone.io/OpenAPITools/openapi-generator)
 
+[`4.2.x`](https://github.com/OpenAPITools/openapi-generator/tree/4.2.x) branch: [![Build Status](https://img.shields.io/travis/OpenAPITools/openapi-generator/4.2.x.svg?label=Integration%20Test)](https://travis-ci.org/OpenAPITools/openapi-generator)
+[![Integration Test2](https://circleci.com/gh/OpenAPITools/openapi-generator/tree/4.2.x.svg?style=shield)](https://circleci.com/gh/OpenAPITools/openapi-generator)
+[![Run Status](https://api.shippable.com/projects/5af6bf74e790f4070084a115/badge?branch=4.2.x)](https://app.shippable.com/github/OpenAPITools/openapi-generator)
+[![Windows Test](https://ci.appveyor.com/api/projects/status/github/openapitools/openapi-generator?branch=4.2.x&svg=true&passingText=Windows%20Test%20-%20OK&failingText=Windows%20Test%20-%20Fails)](https://ci.appveyor.com/project/WilliamCheng/openapi-generator-wh2wu)
+[![JDK11 Build](https://cloud.drone.io/api/badges/OpenAPITools/openapi-generator/status.svg?ref=refs/heads/4.2.x)](https://cloud.drone.io/OpenAPITools/openapi-generator)
+
 [`5.0.x`](https://github.com/OpenAPITools/openapi-generator/tree/5.0.x) branch: [![Build Status](https://img.shields.io/travis/OpenAPITools/openapi-generator/5.0.x.svg?label=Integration%20Test)](https://travis-ci.org/OpenAPITools/openapi-generator)
 [![Integration Test2](https://circleci.com/gh/OpenAPITools/openapi-generator/tree/5.0.x.svg?style=shield)](https://circleci.com/gh/OpenAPITools/openapi-generator)
 [![Run Status](https://api.shippable.com/projects/5af6bf74e790f4070084a115/badge?branch=5.0.x)](https://app.shippable.com/github/OpenAPITools/openapi-generator)
@@ -59,7 +65,7 @@ OpenAPI Generator allows generation of API client libraries (SDK generation), se
 
 |                                | Languages/Frameworks |
 |-|-|
-**API clients**                  | **ActionScript**, **Ada**, **Apex**, **Bash**, **C**, **C#** (.net 2.0, 3.5 or later), **C++** (cpp-restsdk, Qt5, Tizen), **Clojure**, **Dart (1.x, 2.x)**, **Elixir**, **Elm**, **Eiffel**, **Erlang**, **Go**, **Groovy**, **Haskell** (http-client, Servant), **Java** (Jersey1.x, Jersey2.x, OkHttp, Retrofit1.x, Retrofit2.x, Feign, RestTemplate, RESTEasy, Vertx, Google API Client Library for Java, Rest-assured, Spring 5 Web Client), **Kotlin**, **Lua**, **Node.js/JavaScript** (ES5, ES6, AngularJS with Google Closure Compiler annotations, Flow types), **Objective-C**, **OCaml**, **Perl**, **PHP**, **PowerShell**, **Python**, **R**, **Ruby**, **Rust** (rust, rust-server), **Scala** (akka, http4s, scalaz, swagger-async-httpclient), **Swift** (2.x, 3.x, 4.x), **Typescript** (AngularJS, Angular (2.x - 7.x), Aurelia, Axios, Fetch, Inversify, jQuery, Node, Rxjs)
+**API clients**                  | **ActionScript**, **Ada**, **Apex**, **Bash**, **C**, **C#** (.net 2.0, 3.5 or later), **C++** (cpp-restsdk, Qt5, Tizen), **Clojure**, **Dart (1.x, 2.x)**, **Elixir**, **Elm**, **Eiffel**, **Erlang**, **Go**, **Groovy**, **Haskell** (http-client, Servant), **Java** (Jersey1.x, Jersey2.x, OkHttp, Retrofit1.x, Retrofit2.x, Feign, RestTemplate, RESTEasy, Vertx, Google API Client Library for Java, Rest-assured, Spring 5 Web Client), **Kotlin**, **Lua**, **Node.js/JavaScript** (ES5, ES6, AngularJS with Google Closure Compiler annotations, Flow types), **Objective-C**, **OCaml**, **Perl**, **PHP**, **PowerShell**, **Python**, **R**, **Ruby**, **Rust** (rust, rust-server), **Scala** (akka, http4s, scalaz, swagger-async-httpclient), **Swift** (2.x, 3.x, 4.x), **Typescript** (AngularJS, Angular (2.x - 8.x), Aurelia, Axios, Fetch, Inversify, jQuery, Node, Rxjs)
 **Server stubs**                 | **Ada**, **C#** (ASP.NET Core, NancyFx), **C++** (Pistache, Restbed, Qt5 QHTTPEngine), **Erlang**, **F#** (Giraffe), **Go** (net/http, Gin), **Haskell** (Servant), **Java** (MSF4J, Spring, Undertow, JAX-RS: CDI, CXF, Inflector, RestEasy, Play Framework, [PKMST](https://github.com/ProKarma-Inc/pkmst-getting-started-examples)), **Kotlin** (Spring Boot, Ktor), **PHP** (Laravel, Lumen, Slim, Silex, [Symfony](https://symfony.com/), [Zend Expressive](https://github.com/zendframework/zend-expressive)), **Python** (Flask), **NodeJS**, **Ruby** (Sinatra, Rails5), **Rust** (rust-server), **Scala** ([Finch](https://github.com/finagle/finch), [Lagom](https://github.com/lagom/lagom), [Play](https://www.playframework.com/), Scalatra)
 **API documentation generators** | **HTML**, **Confluence Wiki**
 **Configuration files**          | [**Apache2**](https://httpd.apache.org/)
@@ -101,8 +107,9 @@ The OpenAPI Specification has undergone 3 revisions since initial creation in 20
 OpenAPI Generator Version    | Release Date | Notes
 ---------------------------- | ------------ | -----
 5.0.0 (upcoming major release) [SNAPSHOT](https://oss.sonatype.org/content/repositories/snapshots/org/openapitools/openapi-generator-cli/5.0.0-SNAPSHOT/)| 13.05.2020 | Major release with breaking changes (no fallback)
-4.1.0 (upcoming minor release) [SNAPSHOT](https://oss.sonatype.org/content/repositories/snapshots/org/openapitools/openapi-generator-cli/4.1.0-SNAPSHOT/)| 31.07.2019 | Minor release (breaking changes with fallbacks)
-[4.1.0](https://github.com/OpenAPITools/openapi-generator/releases/tag/v4.1.0) (latest stable release) | 09.07.2019 | Patch release (bug fixes, minor enhancements, etc)
+4.2.0 (upcoming minor release) [SNAPSHOT](https://oss.sonatype.org/content/repositories/snapshots/org/openapitools/openapi-generator-cli/4.2.0-SNAPSHOT/)| 09.10.2019 | Minor release (breaking changes with fallbacks)
+4.1.1 (upcoming minor release) [SNAPSHOT](https://oss.sonatype.org/content/repositories/snapshots/org/openapitools/openapi-generator-cli/4.1.1-SNAPSHOT/)| 23.08.2019 | Patch release (bug fixes, enhancements)
+[4.1.0](https://github.com/OpenAPITools/openapi-generator/releases/tag/v4.1.0) (latest stable release) | 09.08.2019 | Minor release (breaking changes with fallbacks)
 
 OpenAPI Spec compatibility: 1.0, 1.1, 1.2, 2.0, 3.0
 
@@ -448,7 +455,6 @@ NAME
 SYNOPSIS
         openapi-generator-cli generate
                 [(-a <authorization> | --auth <authorization>)]
-                [--additional-properties <additional properties>...]
                 [--api-package <api package>] [--artifact-id <artifact id>]
                 [--artifact-version <artifact version>]
                 [(-c <configuration file> | --config <configuration file>)]
@@ -469,12 +475,13 @@ SYNOPSIS
                 [--model-name-prefix <model name prefix>]
                 [--model-name-suffix <model name suffix>]
                 [--model-package <model package>]
-                [(-o <output directory> | --output <output directory>)]
+                [(-o <output directory> | --output <output directory>)] 
+                [(-p <additional properties> | --additional-properties <additional properties>)...]
                 [--package-name <package name>] [--release-note <release note>]
                 [--remove-operation-id-prefix]
                 [--reserved-words-mappings <reserved word mappings>...]
-                [(-s | --skip-overwrite)] [--skip-validate-spec]
-                [--strict-spec <true/false strict behavior>]
+                [(-s | --skip-overwrite)] [--server-variables <server variables>...]
+                [--skip-validate-spec] [--strict-spec <true/false strict behavior>]
                 [(-t <template directory> | --template-dir <template directory>)]
                 [--type-mappings <type mappings>...] [(-v | --verbose)]
 
@@ -790,7 +797,7 @@ If you want to join the committee, please kindly apply by sending an email to te
 | Apex      |  |
 | Bash      | @frol (2017/07) @bkryza (2017/08) @kenjones-cisco (2017/09) |
 | C         | @zhemant (2018/11) |
-| C++       | @ravinikam (2017/07) @stkrwork (2017/07) @etherealjoy (2018/02) @martindelille (2018/03) |
+| C++       | @ravinikam (2017/07) @stkrwork (2017/07) @etherealjoy (2018/02) @martindelille (2018/03) @muttleyxd (2019/08) |
 | C#        | @mandrean (2017/08), @jimschubert (2017/09) [:heart:](https://www.patreon.com/jimschubert) |
 | Clojure   |  |
 | Dart      | @ircecho (2017/07) @swipesight (2018/09) @jaumard (2018/09) |

bin/rust-server-petstore.sh

@@ -38,4 +38,8 @@ for spec_path in modules/openapi-generator/src/test/resources/*/rust-server/* ;
 		 $@"
 
   java $JAVA_OPTS -jar $executable $args
+
+  if [ $? -ne 0 ]; then
+    exit $?
+  fi
 done

bin/typescript-angular-petstore-all.sh

@@ -13,3 +13,4 @@
 ./bin/typescript-angular-v7-petstore-not-provided-in-root-with-npm.sh
 ./bin/typescript-angular-v7-petstore-provided-in-root.sh
 ./bin/typescript-angular-v7-petstore-provided-in-root-with-npm.sh
+./bin/typescript-angular-v8-petstore-provided-in-root-with-npm.sh

bin/typescript-angular-v8-petstore-provided-in-root-with-npm.json

@@ -0,0 +1,7 @@
+{
+  "npmName": "@openapitools/typescript-angular-petstore",
+  "npmVersion": "1.0.0",
+  "npmRepository" : "https://skimdb.npmjs.com/registry",
+  "snapshot" : false,
+  "ngVersion": "8.0.0"
+}

bin/typescript-angular-v8-petstore-provided-in-root-with-npm.sh

@@ -0,0 +1,32 @@
+#!/bin/sh
+
+SCRIPT="$0"
+echo "# START SCRIPT: $SCRIPT"
+
+while [ -h "$SCRIPT" ] ; do
+  ls=`ls -ld "$SCRIPT"`
+  link=`expr "$ls" : '.*-> \(.*\)$'`
+  if expr "$link" : '/.*' > /dev/null; then
+    SCRIPT="$link"
+  else
+    SCRIPT=`dirname "$SCRIPT"`/"$link"
+  fi
+done
+
+if [ ! -d "${APP_DIR}" ]; then
+  APP_DIR=`dirname "$SCRIPT"`/..
+  APP_DIR=`cd "${APP_DIR}"; pwd`
+fi
+
+executable="./modules/openapi-generator-cli/target/openapi-generator-cli.jar"
+
+if [ ! -f "$executable" ]
+then
+  mvn -B clean package
+fi
+
+# if you've executed sbt assembly previously it will use that instead.
+export JAVA_OPTS="${JAVA_OPTS} -Xmx1024M -DloggerPath=conf/log4j.properties"
+ags="generate -i modules/openapi-generator/src/test/resources/2_0/petstore.yaml -g typescript-angular -c bin/typescript-angular-v8-petstore-provided-in-root-with-npm.json -o samples/client/petstore/typescript-angular-v8-provided-in-root/builds/with-npm --additional-properties ngVersion=8.0.0 $@"
+
+java $JAVA_OPTS -jar $executable $ags

bin/utils/ensure-up-to-date

@@ -12,6 +12,7 @@ sleep 5
 # LIST OF SCRIPTS:
 declare -a scripts=(
 # SAMPLES
+"./bin/ruby-client-petstore.sh"
 "./bin/openapi3/ruby-client-petstore.sh"
 "./bin/openapi3/ruby-client-faraday-petstore.sh"
 "./bin/java-petstore-all.sh"
@@ -57,11 +58,11 @@ declare -a scripts=(
 "./bin/groovy-petstore.sh"
 "./bin/apex-petstore.sh"
 "./bin/perl-petstore-all.sh"
+"./bin/dart-jaguar-petstore.sh"
 #"./bin/elm-petstore-all.sh"
 "./bin/meta-codegen.sh"
 # OTHERS
 "./bin/utils/export_docs_generators.sh"
-"./bin/utils/export_generators_docusaurus_index.sh"
 "./bin/utils/copy-to-website.sh"
 "./bin/utils/export_generators_readme.sh")
 

bin/utils/export_docs_generators.sh

@@ -5,7 +5,7 @@ echo "# START SCRIPT: ${SCRIPT}"
 
 executable="./modules/openapi-generator-cli/target/openapi-generator-cli.jar"
 
-for GENERATOR in $(java -jar ${executable} list --short | sed -e 's/,/\'$'\n''/g')
+for GENERATOR in $(java -jar ${executable} list --short --include all | sed -e 's/,/\'$'\n''/g')
 do
     ./bin/utils/export_generator.sh ${GENERATOR}
 done

bin/utils/export_generators_docusaurus_index.sh

@@ -1,20 +0,0 @@
-#!/bin/sh
-
-SCRIPT="$0"
-echo "# START SCRIPT: $SCRIPT"
-
-executable="./modules/openapi-generator-cli/target/openapi-generator-cli.jar"
-
-\rm -rf docs/generators.md
-
-cat > docs/generators.md << EOF
----
-id: generators
-title: Generators List
----
-
-EOF
-
-java -jar $executable list --docsite >> docs/generators.md
-
-echo "Wrote $(pwd)/docs/generators.md"

bin/utils/export_generators_readme.sh

@@ -15,6 +15,6 @@ title: Generators List
 
 EOF
 
-java -jar $executable list | sed -e 's/\([A-Z]*\) generators:/* \1 generators:/g' -e 's/- \([a-z0-9\-]*\)/- [\1]\(generators\/\1.md\)/g' >> docs/generators.md
+java -jar $executable list --docsite --include all >> docs/generators.md
 
 echo "Wrote $(pwd)/docs/generators.md"

bin/utils/openapi-generator-cli.sh

@@ -42,7 +42,7 @@ artifactid=openapi-generator-cli
 ver=${OPENAPI_GENERATOR_VERSION:-$(latest.tag $ghrepo)}
 
 jar=${artifactid}-${ver}.jar
-DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+DIR=${OPENAPI_GENERATOR_DOWLOAD_CACHE_DIR:-"$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"}
 
 if [ ! -f ${DIR}/${jar} ]; then
   repo="central::default::https://repo1.maven.org/maven2/"

bin/windows/typescript-angular-petstore-all.bat

@@ -11,4 +11,4 @@ call .\bin\windows\typescript-angular-v7-provided-in-root.bat
 call .\bin\windows\typescript-angular-v7-provided-in-root-with-npm.bat
 call .\bin\windows\typescript-angular-v7-not-provided-in-root.bat
 call .\bin\windows\typescript-angular-v7-not-provided-in-root-with-npm.bat
-
+call .\bin\windows\typescript-angular-v8-provided-in-root-with-npm.bat

bin/windows/typescript-angular-v8-provided-in-root-with-npm.bat

@@ -0,0 +1,9 @@
+set executable=.\modules\openapi-generator-cli\target\openapi-generator-cli.jar
+
+If Not Exist %executable% (
+  mvn clean package
+)
+
+set ags=generate -i modules\openapi-generator\src\test\resources\2_0\petstore.yaml -g typescript-angular -c bin/typescript-angular-v8-petstore-provided-in-root-with-npm.json -o samples\client\petstore\typescript-angular-v8-provided-in-root\builds\with-npm --additional-properties ngVersion=8.0.0
+
+java %JAVA_OPTS% -jar %executable% %ags%

docs/generators.md

@@ -5,132 +5,132 @@ title: Generators List
 
 The following generators are available:
 
-* CLIENT generators:
-    - [ada](generators/ada.md)
-    - [android](generators/android.md)
-    - [apex](generators/apex.md)
-    - [bash](generators/bash.md)
-    - [c](generators/c.md)
-    - [clojure](generators/clojure.md)
-    - [cpp-qt5-client](generators/cpp-qt5-client.md)
-    - [cpp-restsdk](generators/cpp-restsdk.md)
-    - [cpp-tizen](generators/cpp-tizen.md)
-    - [csharp](generators/csharp.md)
-    - [csharp-dotnet2](generators/csharp-dotnet2.md) (deprecated)
-    - [csharp-netcore](generators/csharp-netcore.md)
-    - [dart](generators/dart.md)
-    - [dart-jaguar](generators/dart-jaguar.md)
-    - [eiffel](generators/eiffel.md)
-    - [elixir](generators/elixir.md)
-    - [elm](generators/elm.md)
-    - [erlang-client](generators/erlang-client.md)
-    - [erlang-proper](generators/erlang-proper.md)
-    - [flash](generators/flash.md)
-    - [go](generators/go.md)
-    - [go-experimental](generators/go-experimental.md)
-    - [groovy](generators/groovy.md)
-    - [haskell-http-client](generators/haskell-http-client.md)
-    - [java](generators/java.md)
-    - [javascript](generators/javascript.md)
-    - [javascript-closure-angular](generators/javascript-closure-angular.md)
-    - [javascript-flowtyped](generators/javascript-flowtyped.md)
-    - [jaxrs-cxf-client](generators/jaxrs-cxf-client.md)
-    - [jmeter](generators/jmeter.md)
-    - [kotlin](generators/kotlin.md)
-    - [lua](generators/lua.md)
-    - [objc](generators/objc.md)
-    - [ocaml](generators/ocaml.md)
-    - [perl](generators/perl.md)
-    - [php](generators/php.md)
-    - [powershell](generators/powershell.md)
-    - [python](generators/python.md)
-    - [python-experimental](generators/python-experimental.md)
-    - [r](generators/r.md)
-    - [ruby](generators/ruby.md)
-    - [rust](generators/rust.md)
-    - [scala-akka](generators/scala-akka.md)
-    - [scala-gatling](generators/scala-gatling.md)
-    - [scala-httpclient-deprecated](generators/scala-httpclient-deprecated.md) (deprecated)
-    - [scalaz](generators/scalaz.md)
-    - [swift2-deprecated](generators/swift2-deprecated.md) (deprecated)
-    - [swift3-deprecated](generators/swift3-deprecated.md) (deprecated)
-    - [swift4](generators/swift4.md)
-    - [typescript-angular](generators/typescript-angular.md)
-    - [typescript-angularjs](generators/typescript-angularjs.md)
-    - [typescript-aurelia](generators/typescript-aurelia.md)
-    - [typescript-axios](generators/typescript-axios.md)
-    - [typescript-fetch](generators/typescript-fetch.md)
-    - [typescript-inversify](generators/typescript-inversify.md)
-    - [typescript-jquery](generators/typescript-jquery.md)
-    - [typescript-node](generators/typescript-node.md)
-    - [typescript-rxjs](generators/typescript-rxjs.md)
+## CLIENT generators
+* [ada](generators/ada)  
+* [android](generators/android)  
+* [apex](generators/apex)  
+* [bash](generators/bash)  
+* [c](generators/c)  
+* [clojure](generators/clojure)  
+* [cpp-qt5-client](generators/cpp-qt5-client)  
+* [cpp-restsdk](generators/cpp-restsdk)  
+* [cpp-tizen](generators/cpp-tizen)  
+* [csharp](generators/csharp)  
+* [csharp-dotnet2 (deprecated)](generators/csharp-dotnet2)  
+* [csharp-netcore](generators/csharp-netcore)  
+* [dart](generators/dart)  
+* [dart-jaguar](generators/dart-jaguar)  
+* [eiffel](generators/eiffel)  
+* [elixir](generators/elixir)  
+* [elm](generators/elm)  
+* [erlang-client](generators/erlang-client)  
+* [erlang-proper](generators/erlang-proper)  
+* [flash](generators/flash)  
+* [go](generators/go)  
+* [go-experimental (experimental)](generators/go-experimental)  
+* [groovy](generators/groovy)  
+* [haskell-http-client](generators/haskell-http-client)  
+* [java](generators/java)  
+* [javascript](generators/javascript)  
+* [javascript-closure-angular](generators/javascript-closure-angular)  
+* [javascript-flowtyped](generators/javascript-flowtyped)  
+* [jaxrs-cxf-client](generators/jaxrs-cxf-client)  
+* [jmeter](generators/jmeter)  
+* [kotlin](generators/kotlin)  
+* [lua](generators/lua)  
+* [objc](generators/objc)  
+* [ocaml](generators/ocaml)  
+* [perl](generators/perl)  
+* [php](generators/php)  
+* [powershell](generators/powershell)  
+* [python](generators/python)  
+* [python-experimental (experimental)](generators/python-experimental)  
+* [r](generators/r)  
+* [ruby](generators/ruby)  
+* [rust](generators/rust)  
+* [scala-akka](generators/scala-akka)  
+* [scala-gatling](generators/scala-gatling)  
+* [scala-httpclient-deprecated (deprecated)](generators/scala-httpclient-deprecated)  
+* [scalaz](generators/scalaz)  
+* [swift2-deprecated (deprecated)](generators/swift2-deprecated)  
+* [swift3-deprecated (deprecated)](generators/swift3-deprecated)  
+* [swift4](generators/swift4)  
+* [typescript-angular](generators/typescript-angular)  
+* [typescript-angularjs](generators/typescript-angularjs)  
+* [typescript-aurelia](generators/typescript-aurelia)  
+* [typescript-axios](generators/typescript-axios)  
+* [typescript-fetch](generators/typescript-fetch)  
+* [typescript-inversify](generators/typescript-inversify)  
+* [typescript-jquery](generators/typescript-jquery)  
+* [typescript-node](generators/typescript-node)  
+* [typescript-rxjs](generators/typescript-rxjs)  
 
 
-* SERVER generators:
-    - [ada-server](generators/ada-server.md)
-    - [aspnetcore](generators/aspnetcore.md)
-    - [cpp-pistache-server](generators/cpp-pistache-server.md)
-    - [cpp-qt5-qhttpengine-server](generators/cpp-qt5-qhttpengine-server.md)
-    - [cpp-restbed-server](generators/cpp-restbed-server.md)
-    - [csharp-nancyfx](generators/csharp-nancyfx.md)
-    - [erlang-server](generators/erlang-server.md)
-    - [fsharp-giraffe-server](generators/fsharp-giraffe-server.md)
-    - [go-gin-server](generators/go-gin-server.md)
-    - [go-server](generators/go-server.md)
-    - [graphql-nodejs-express-server](generators/graphql-nodejs-express-server.md)
-    - [haskell](generators/haskell.md)
-    - [java-inflector](generators/java-inflector.md)
-    - [java-msf4j](generators/java-msf4j.md)
-    - [java-pkmst](generators/java-pkmst.md)
-    - [java-play-framework](generators/java-play-framework.md)
-    - [java-undertow-server](generators/java-undertow-server.md)
-    - [java-vertx](generators/java-vertx.md)
-    - [jaxrs-cxf](generators/jaxrs-cxf.md)
-    - [jaxrs-cxf-cdi](generators/jaxrs-cxf-cdi.md)
-    - [jaxrs-cxf-extended](generators/jaxrs-cxf-extended.md)
-    - [jaxrs-jersey](generators/jaxrs-jersey.md)
-    - [jaxrs-resteasy](generators/jaxrs-resteasy.md)
-    - [jaxrs-resteasy-eap](generators/jaxrs-resteasy-eap.md)
-    - [jaxrs-spec](generators/jaxrs-spec.md)
-    - [kotlin-server](generators/kotlin-server.md)
-    - [kotlin-spring](generators/kotlin-spring.md)
-    - [nodejs-express-server](generators/nodejs-express-server.md) (beta)
-    - [nodejs-server-deprecated](generators/nodejs-server-deprecated.md) (deprecated)
-    - [php-laravel](generators/php-laravel.md)
-    - [php-lumen](generators/php-lumen.md)
-    - [php-silex](generators/php-silex.md)
-    - [php-slim](generators/php-slim.md)
-    - [php-symfony](generators/php-symfony.md)
-    - [php-ze-ph](generators/php-ze-ph.md)
-    - [python-aiohttp](generators/python-aiohttp.md)
-    - [python-blueplanet](generators/python-blueplanet.md)
-    - [python-flask](generators/python-flask.md)
-    - [ruby-on-rails](generators/ruby-on-rails.md)
-    - [ruby-sinatra](generators/ruby-sinatra.md)
-    - [rust-server](generators/rust-server.md)
-    - [scala-finch](generators/scala-finch.md)
-    - [scala-lagom-server](generators/scala-lagom-server.md)
-    - [scala-play-server](generators/scala-play-server.md)
-    - [scalatra](generators/scalatra.md)
-    - [spring](generators/spring.md)
+## SERVER generators
+* [ada-server](generators/ada-server)  
+* [aspnetcore](generators/aspnetcore)  
+* [cpp-pistache-server](generators/cpp-pistache-server)  
+* [cpp-qt5-qhttpengine-server](generators/cpp-qt5-qhttpengine-server)  
+* [cpp-restbed-server](generators/cpp-restbed-server)  
+* [csharp-nancyfx](generators/csharp-nancyfx)  
+* [erlang-server](generators/erlang-server)  
+* [fsharp-giraffe-server](generators/fsharp-giraffe-server)  
+* [go-gin-server](generators/go-gin-server)  
+* [go-server](generators/go-server)  
+* [graphql-nodejs-express-server](generators/graphql-nodejs-express-server)  
+* [haskell](generators/haskell)  
+* [java-inflector](generators/java-inflector)  
+* [java-msf4j](generators/java-msf4j)  
+* [java-pkmst](generators/java-pkmst)  
+* [java-play-framework](generators/java-play-framework)  
+* [java-undertow-server](generators/java-undertow-server)  
+* [java-vertx](generators/java-vertx)  
+* [jaxrs-cxf](generators/jaxrs-cxf)  
+* [jaxrs-cxf-cdi](generators/jaxrs-cxf-cdi)  
+* [jaxrs-cxf-extended](generators/jaxrs-cxf-extended)  
+* [jaxrs-jersey](generators/jaxrs-jersey)  
+* [jaxrs-resteasy](generators/jaxrs-resteasy)  
+* [jaxrs-resteasy-eap](generators/jaxrs-resteasy-eap)  
+* [jaxrs-spec](generators/jaxrs-spec)  
+* [kotlin-server](generators/kotlin-server)  
+* [kotlin-spring](generators/kotlin-spring)  
+* [nodejs-express-server (beta)](generators/nodejs-express-server)  
+* [nodejs-server-deprecated (deprecated)](generators/nodejs-server-deprecated)  
+* [php-laravel](generators/php-laravel)  
+* [php-lumen](generators/php-lumen)  
+* [php-silex](generators/php-silex)  
+* [php-slim](generators/php-slim)  
+* [php-symfony](generators/php-symfony)  
+* [php-ze-ph](generators/php-ze-ph)  
+* [python-aiohttp](generators/python-aiohttp)  
+* [python-blueplanet](generators/python-blueplanet)  
+* [python-flask](generators/python-flask)  
+* [ruby-on-rails](generators/ruby-on-rails)  
+* [ruby-sinatra](generators/ruby-sinatra)  
+* [rust-server](generators/rust-server)  
+* [scala-finch](generators/scala-finch)  
+* [scala-lagom-server](generators/scala-lagom-server)  
+* [scala-play-server](generators/scala-play-server)  
+* [scalatra](generators/scalatra)  
+* [spring](generators/spring)  
 
 
-* DOCUMENTATION generators:
-    - [cwiki](generators/cwiki.md)
-    - [dynamic-html](generators/dynamic-html.md)
-    - [html](generators/html.md)
-    - [html2](generators/html2.md)
-    - [openapi](generators/openapi.md)
-    - [openapi-yaml](generators/openapi-yaml.md)
+## DOCUMENTATION generators
+* [cwiki](generators/cwiki)  
+* [dynamic-html](generators/dynamic-html)  
+* [html](generators/html)  
+* [html2](generators/html2)  
+* [openapi](generators/openapi)  
+* [openapi-yaml](generators/openapi-yaml)  
 
 
-* SCHEMA generators:
-    - [mysql-schema](generators/mysql-schema.md)
+## SCHEMA generators
+* [mysql-schema](generators/mysql-schema)  
 
 
-* CONFIG generators:
-    - [apache2](generators/apache2.md)
-    - [graphql-schema](generators/graphql-schema.md)
+## CONFIG generators
+* [apache2](generators/apache2)  
+* [graphql-schema](generators/graphql-schema)  
 
 
 

docs/generators/dart-jaguar.md

@@ -11,12 +11,12 @@ sidebar_label: dart-jaguar
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
-|browserClient|Is the client browser based| |null|
+|browserClient|Is the client browser based (for Dart 1.x only)| |null|
 |pubName|Name in generated pubspec| |null|
 |pubVersion|Version in generated pubspec| |null|
 |pubDescription|Description in generated pubspec| |null|
 |useEnumExtension|Allow the 'x-enum-values' extension for enums| |null|
-|sourceFolder|source folder for generated code| |null|
-|supportDart2|support dart2| |true|
+|sourceFolder|Source folder for generated code| |null|
+|supportDart2|Support Dart 2.x| |true|
 |nullableFields|Is the null fields should be in the JSON payload| |null|
 |serialization|Choose serialization format JSON or PROTO is supported| |null|

docs/generators/dart.md

@@ -11,10 +11,10 @@ sidebar_label: dart
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
-|browserClient|Is the client browser based| |null|
+|browserClient|Is the client browser based (for Dart 1.x only)| |null|
 |pubName|Name in generated pubspec| |null|
 |pubVersion|Version in generated pubspec| |null|
 |pubDescription|Description in generated pubspec| |null|
 |useEnumExtension|Allow the 'x-enum-values' extension for enums| |null|
-|sourceFolder|source folder for generated code| |null|
-|supportDart2|support dart2| |true|
+|sourceFolder|Source folder for generated code| |null|
+|supportDart2|Support Dart 2.x| |true|

docs/usage.md

@@ -38,9 +38,15 @@ NAME
         openapi-generator-cli list - Lists the available generators
 
 SYNOPSIS
-        openapi-generator-cli list [(-s | --short)]
+        openapi-generator-cli list [(-i <include> | --include <include>)]
+                [(-s | --short)]
 
 OPTIONS
+        -i <include>, --include <include>
+            comma-separated list of stability indexes to include (value:
+            all,beta,stable,experimental,deprecated). Excludes deprecated by
+            default.
+
         -s, --short
             shortened output (suitable for scripting)
 
@@ -210,13 +216,14 @@ This command takes one or more parameters representing the args list you would o
 
 ```bash
 openapi-generator completion config-help
---named-header
 -o
 --output
+--named-header
 -g
 --generator-name
--l
---lang
+-f
+--format
+--markdown-header
 ```
 
 An example bash completion script can be found in the repo at [scripts/openapi-generator-cli-completion.bash](https://github.com/OpenAPITools/openapi-generator/blob/master/scripts/openapi-generator-cli-completion.bash).
@@ -235,7 +242,6 @@ NAME
 SYNOPSIS
         openapi-generator-cli generate
                 [(-a <authorization> | --auth <authorization>)]
-                [--additional-properties <additional properties>...]
                 [--api-package <api package>] [--artifact-id <artifact id>]
                 [--artifact-version <artifact version>]
                 [(-c <configuration file> | --config <configuration file>)]
@@ -256,15 +262,15 @@ SYNOPSIS
                 [--model-name-prefix <model name prefix>]
                 [--model-name-suffix <model name suffix>]
                 [--model-package <model package>]
-                [(-o <output directory> | --output <output directory>)]
+                [(-o <output directory> | --output <output directory>)] 
+                [(-p <additional properties> | --additional-properties <additional properties>)...]
                 [--package-name <package name>] [--release-note <release note>]
                 [--remove-operation-id-prefix]
                 [--reserved-words-mappings <reserved word mappings>...]
-                [(-s | --skip-overwrite)] [--skip-validate-spec]
-                [--strict-spec <true/false strict behavior>]
+                [(-s | --skip-overwrite)] [--server-variables <server variables>...]
+                [--skip-validate-spec] [--strict-spec <true/false strict behavior>]
                 [(-t <template directory> | --template-dir <template directory>)]
                 [--type-mappings <type mappings>...] [(-v | --verbose)]
-
 ```
 
 <details>
@@ -277,19 +283,16 @@ OPTIONS
             remotely. Pass in a URL-encoded string of name:header with a comma
             separating multiple values
 
-        --additional-properties <additional properties>
-            sets additional properties that can be referenced by the mustache
-            templates in the format of name=value,name=value. You can also have
-            multiple occurrences of this option.
-
         --api-package <api package>
             package for generated api classes
 
         --artifact-id <artifact id>
-            artifactId in generated pom.xml
+            artifactId in generated pom.xml. This also becomes part of the
+            generated library's filename
 
         --artifact-version <artifact version>
-            artifact version in generated pom.xml
+            artifact version in generated pom.xml. This also becomes part of the
+            generated library's filename
 
         -c <configuration file>, --config <configuration file>
             Path to configuration file configuration file. It can be json or
@@ -382,6 +385,12 @@ OPTIONS
         -o <output directory>, --output <output directory>
             where to write the generated files (current dir by default)
 
+        -p <additional properties>, --additional-properties <additional
+        properties>
+            sets additional properties that can be referenced by the mustache
+            templates in the format of name=value,name=value. You can also have
+            multiple occurrences of this option.
+
         --package-name <package name>
             package for generated classes (where supported)
 
@@ -400,6 +409,10 @@ OPTIONS
             specifies if the existing files should be overwritten during the
             generation.
 
+        --server-variables <server variables>
+            sets server variables for spec documents which support variable
+            templating of servers.
+
         --skip-validate-spec
             Skips the default behavior of validating an input specification.
 

modules/openapi-generator-cli/pom.xml

@@ -4,7 +4,7 @@
         <groupId>org.openapitools</groupId>
         <artifactId>openapi-generator-project</artifactId>
         <!-- RELEASE_VERSION -->
-        <version>4.1.0</version>
+        <version>4.1.1-SNAPSHOT</version>
         <!-- /RELEASE_VERSION -->
         <relativePath>../..</relativePath>
     </parent>

modules/openapi-generator-cli/src/main/java/org/openapitools/codegen/cmd/Generate.java

@@ -18,13 +18,7 @@
 package org.openapitools.codegen.cmd;
 
 import static org.apache.commons.lang3.StringUtils.isNotEmpty;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyAdditionalPropertiesKvpList;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyImportMappingsKvpList;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyInstantiationTypesKvpList;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyLanguageSpecificPrimitivesCsvList;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyReservedWordsMappingsKvpList;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applySystemPropertiesKvpList;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyTypeMappingsKvpList;
+import static org.openapitools.codegen.config.CodegenConfiguratorUtils.*;
 
 import ch.qos.logback.classic.LoggerContext;
 import ch.qos.logback.core.spi.FilterAttachable;
@@ -160,6 +154,12 @@ public class Generate implements Runnable {
                     + " You can also have multiple occurrences of this option.")
     private List<String> importMappings = new ArrayList<>();
 
+    @Option(
+            name = {"--server-variables"},
+            title = "server variables",
+            description = "sets server variables overrides for spec documents which support variable templating of servers.")
+    private List<String> serverVariableOverrides = new ArrayList<>();
+
     @Option(name = {"--invoker-package"}, title = "invoker package",
             description = CodegenConstants.INVOKER_PACKAGE_DESC)
     private String invokerPackage;
@@ -393,6 +393,7 @@ public class Generate implements Runnable {
         applyAdditionalPropertiesKvpList(additionalProperties, configurator);
         applyLanguageSpecificPrimitivesCsvList(languageSpecificPrimitives, configurator);
         applyReservedWordsMappingsKvpList(reservedWordsMappings, configurator);
+        applyServerVariablesKvpList(serverVariableOverrides, configurator);
 
         try {
             final ClientOptInput clientOptInput = configurator.toClientOptInput();

modules/openapi-generator-cli/src/main/java/org/openapitools/codegen/cmd/ListGenerators.java

@@ -5,15 +5,14 @@ import com.google.common.base.Objects;
 import io.airlift.airline.Command;
 import io.airlift.airline.Option;
 
+import org.apache.commons.lang3.StringUtils;
 import org.openapitools.codegen.CodegenConfig;
 import org.openapitools.codegen.CodegenConfigLoader;
 import org.openapitools.codegen.CodegenType;
 import org.openapitools.codegen.meta.GeneratorMetadata;
 import org.openapitools.codegen.meta.Stability;
 
-import java.util.Comparator;
-import java.util.List;
-import java.util.Locale;
+import java.util.*;
 import java.util.stream.Collectors;
 
 // NOTE: List can later have subcommands such as list languages, list types, list frameworks, etc.
@@ -26,9 +25,31 @@ public class ListGenerators implements Runnable {
     @Option(name = {"-d", "--docsite" }, description = "format for docusaurus site output", hidden = true)
     private Boolean docusaurus = false;
 
+    @Option(name = {"-i", "--include" },
+            description = "comma-separated list of stability indexes to include (value: all,beta,stable,experimental,deprecated). Excludes deprecated by default.",
+            allowedValues = { "all", "beta", "stable", "experimental", "deprecated" })
+    private String include = "stable,beta,experimental";
+
     @Override
     public void run() {
-        List<CodegenConfig> generators = CodegenConfigLoader.getAll();
+        List<CodegenConfig> generators = new ArrayList<>();
+        List<Stability> stabilities = Arrays.asList(Stability.values());
+
+        if (!StringUtils.isEmpty(include)) {
+            List<String> includes = Arrays.asList(include.split(","));
+            if (includes.size() != 0 && !includes.contains("all")) {
+                stabilities = includes.stream()
+                        .map(Stability::forDescription)
+                        .collect(Collectors.toList());
+            }
+        }
+
+        for (CodegenConfig codegenConfig : CodegenConfigLoader.getAll()) {
+            GeneratorMetadata meta = codegenConfig.getGeneratorMetadata();
+            if (meta != null && stabilities.contains(meta.getStability())) {
+                generators.add(codegenConfig);
+            }
+        }
 
         StringBuilder sb = new StringBuilder();
 

modules/openapi-generator-core/pom.xml

@@ -6,7 +6,7 @@
     <artifactId>openapi-generator-project</artifactId>
     <groupId>org.openapitools</groupId>
     <!-- RELEASE_VERSION -->
-    <version>4.1.0</version>
+    <version>4.1.1-SNAPSHOT</version>
     <!-- /RELEASE_VERSION -->
     <relativePath>../..</relativePath>
   </parent>

modules/openapi-generator-core/src/main/java/org/openapitools/codegen/config/GeneratorSettings.java

@@ -52,6 +52,7 @@ public final class GeneratorSettings implements Serializable {
     private ImmutableMap<String, String> importMappings;
     private ImmutableSet<String> languageSpecificPrimitives;
     private ImmutableMap<String, String> reservedWordMappings;
+    private ImmutableMap<String, String> serverVariables;
 
     private String gitUserId;
     private String gitRepoId;
@@ -245,6 +246,17 @@ public final class GeneratorSettings implements Serializable {
         return reservedWordMappings;
     }
 
+
+    /**
+     * Gets server variable. Values defined here will be attempted to be replaced within a templated server object.
+     *
+     * @return the server variables
+     */
+    public Map<String, String> getServerVariables() {
+        return serverVariables;
+    }
+
+
     /**
      * Gets git user id. e.g. <strong>openapitools</strong>.
      * <p>
@@ -311,6 +323,7 @@ public final class GeneratorSettings implements Serializable {
         importMappings = ImmutableMap.copyOf(builder.importMappings);
         languageSpecificPrimitives = ImmutableSet.copyOf(builder.languageSpecificPrimitives);
         reservedWordMappings = ImmutableMap.copyOf(builder.reservedWordMappings);
+        serverVariables = ImmutableMap.copyOf(builder.serverVariables);
         gitUserId = builder.gitUserId;
         gitRepoId = builder.gitRepoId;
         releaseNote = builder.releaseNote;
@@ -373,6 +386,7 @@ public final class GeneratorSettings implements Serializable {
         importMappings = ImmutableMap.of();
         languageSpecificPrimitives = ImmutableSet.of();
         reservedWordMappings = ImmutableMap.of();
+        serverVariables = ImmutableMap.of();
     }
 
     private void setDefaults() {
@@ -394,12 +408,6 @@ public final class GeneratorSettings implements Serializable {
         return new Builder();
     }
 
-    /**
-     * New builder builder.
-     *
-     * @param copy the copy
-     * @return the builder
-     */
     public static Builder newBuilder(GeneratorSettings copy) {
         Builder builder = new Builder();
         builder.generatorName = copy.getGeneratorName();
@@ -419,6 +427,7 @@ public final class GeneratorSettings implements Serializable {
         builder.importMappings = new HashMap<>(copy.getImportMappings());
         builder.languageSpecificPrimitives = new HashSet<>(copy.getLanguageSpecificPrimitives());
         builder.reservedWordMappings = new HashMap<>(copy.getReservedWordMappings());
+        builder.serverVariables = new HashMap<>(copy.getServerVariables());
         builder.gitUserId = copy.getGitUserId();
         builder.gitRepoId = copy.getGitRepoId();
         builder.releaseNote = copy.getReleaseNote();
@@ -449,6 +458,7 @@ public final class GeneratorSettings implements Serializable {
         private Map<String, String> importMappings;
         private Set<String> languageSpecificPrimitives;
         private Map<String, String> reservedWordMappings;
+        private Map<String, String> serverVariables;
         private String gitUserId;
         private String gitRepoId;
         private String releaseNote;
@@ -464,6 +474,7 @@ public final class GeneratorSettings implements Serializable {
             importMappings = new HashMap<>();
             languageSpecificPrimitives = new HashSet<>();
             reservedWordMappings = new HashMap<>();
+            serverVariables = new HashMap<>();
 
             gitUserId = DEFAULT_GIT_USER_ID;
             gitRepoId = DEFAULT_GIT_REPO_ID;
@@ -617,6 +628,17 @@ public final class GeneratorSettings implements Serializable {
             return this;
         }
 
+        /**
+         * Sets the {@code serverVariables} and returns a reference to this Builder so that the methods can be chained together.
+         *
+         * @param serverVariables the {@code serverVariables} to set
+         * @return a reference to this Builder
+         */
+        public Builder withServerVariables(Map<String, String> serverVariables) {
+            this.serverVariables = serverVariables;
+            return this;
+        }
+
         /**
          * Sets the {@code typeMappings} and returns a reference to this Builder so that the methods can be chained together.
          *
@@ -731,6 +753,22 @@ public final class GeneratorSettings implements Serializable {
             return this;
         }
 
+
+        /**
+         * Sets a single {@code serverVariables} and returns a reference to this Builder so that the methods can be chained together.
+         *
+         * @param key   A key for some server variable
+         * @param value The value of some server variable to be replaced in a templated server object.
+         * @return a reference to this Builder
+         */
+        public Builder withServerVariable(String key, String value) {
+            if (this.serverVariables == null) {
+                this.serverVariables = new HashMap<>();
+            }
+            this.serverVariables.put(key, value);
+            return this;
+        }
+
         /**
          * Sets the {@code gitUserId} and returns a reference to this Builder so that the methods can be chained together.
          *

modules/openapi-generator-core/src/main/java/org/openapitools/codegen/meta/Stability.java

@@ -50,4 +50,14 @@ public enum Stability {
      * @return The descriptive value of this enum.
      */
     public String value() { return description; }
+
+    public static Stability forDescription(String description) {
+        for (Stability value: values()) {
+            if (value.description.equals(description)) {
+                return value;
+            }
+        }
+
+        throw new IllegalArgumentException("description not found in the available values.");
+    }
 }

modules/openapi-generator-gradle-plugin/README.adoc

@@ -374,6 +374,18 @@ openApiGenerate {
 
 |===
 
+=== openApiGenerators
+
+.Options
+|===
+|Key |Data Type |Default |Description
+
+|include
+|String[]
+|None
+|A list of stability indexes to include (values: all,beta,stable,experimental,deprecated). Excludes deprecated by default.
+
+|===
 
 == Examples
 

modules/openapi-generator-gradle-plugin/build.gradle

@@ -1,6 +1,7 @@
 buildscript {
     ext.kotlin_version = '1.2.61'
     repositories {
+        mavenLocal()
         mavenCentral()
         maven {
             url "https://plugins.gradle.org/m2/"

modules/openapi-generator-gradle-plugin/gradle.properties

@@ -1,5 +1,5 @@
 # RELEASE_VERSION
-openApiGeneratorVersion=4.1.0
+openApiGeneratorVersion=4.1.1-SNAPSHOT
 # /RELEASE_VERSION
 
 # BEGIN placeholders

modules/openapi-generator-gradle-plugin/pom.xml

@@ -4,7 +4,7 @@
         <groupId>org.openapitools</groupId>
         <artifactId>openapi-generator-project</artifactId>
         <!-- RELEASE_VERSION -->
-        <version>4.1.0</version>
+        <version>4.1.1-SNAPSHOT</version>
         <!-- /RELEASE_VERSION -->
         <relativePath>../..</relativePath>
     </parent>

modules/openapi-generator-gradle-plugin/src/main/kotlin/org/openapitools/generator/gradle/plugin/OpenApiGeneratorPlugin.kt

@@ -19,6 +19,7 @@ package org.openapitools.generator.gradle.plugin
 import org.gradle.api.Plugin
 import org.gradle.api.Project
 import org.openapitools.generator.gradle.plugin.extensions.OpenApiGeneratorGenerateExtension
+import org.openapitools.generator.gradle.plugin.extensions.OpenApiGeneratorGeneratorsExtension
 import org.openapitools.generator.gradle.plugin.extensions.OpenApiGeneratorMetaExtension
 import org.openapitools.generator.gradle.plugin.extensions.OpenApiGeneratorValidateExtension
 import org.openapitools.generator.gradle.plugin.tasks.GenerateTask
@@ -53,12 +54,20 @@ class OpenApiGeneratorPlugin : Plugin<Project> {
                     project
             )
 
+            val generators = extensions.create(
+                "openApiGenerators",
+                OpenApiGeneratorGeneratorsExtension::class.java,
+                project
+            )
+
             generate.outputDir.set("$buildDir/generate-resources/main")
 
             tasks.apply {
                 create("openApiGenerators", GeneratorsTask::class.java) {
                     group = pluginGroup
                     description = "Lists generators available via Open API Generators."
+
+                    include.set(generators.include)
                 }
 
                 create("openApiMeta", MetaTask::class.java) {
@@ -99,6 +108,7 @@ class OpenApiGeneratorPlugin : Plugin<Project> {
                     instantiationTypes.set(generate.instantiationTypes)
                     typeMappings.set(generate.typeMappings)
                     additionalProperties.set(generate.additionalProperties)
+                    serverVariables.set(generate.serverVariables)
                     languageSpecificPrimitives.set(generate.languageSpecificPrimitives)
                     importMappings.set(generate.importMappings)
                     invokerPackage.set(generate.invokerPackage)

modules/openapi-generator-gradle-plugin/src/main/kotlin/org/openapitools/generator/gradle/plugin/extensions/OpenApiGeneratorGenerateExtension.kt

@@ -120,6 +120,11 @@ open class OpenApiGeneratorGenerateExtension(project: Project) {
      */
     val additionalProperties = project.objects.property<Map<String, String>>()
 
+    /**
+     * Sets server variable for server URL template substitution, in the format of name=value,name=value.
+     */
+    val serverVariables = project.objects.property<Map<String, String>>()
+
     /**
      * Specifies additional language specific primitive types in the format of type1,type2,type3,type3. For example: String,boolean,Boolean,Double.
      */

modules/openapi-generator-gradle-plugin/src/main/kotlin/org/openapitools/generator/gradle/plugin/extensions/OpenApiGeneratorGeneratorsExtension.kt

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2019 OpenAPI-Generator Contributors (https://openapi-generator.tech)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.openapitools.generator.gradle.plugin.extensions
+
+import org.gradle.api.Project
+import org.gradle.api.tasks.Internal
+import org.gradle.kotlin.dsl.listProperty
+import org.openapitools.codegen.meta.Stability
+
+/**
+ * Gradle project level extension object definition for the generators task
+ *
+ * @author Jim Schubert
+ */
+open class OpenApiGeneratorGeneratorsExtension(project: Project) {
+    /**
+     * A list of stability indexes to include (value: all,beta,stable,experimental,deprecated). Excludes deprecated by default.
+     */
+    val include = project.objects.listProperty<String>()
+
+    init {
+        applyDefaults()
+    }
+
+    @Suppress("MemberVisibilityCanBePrivate")
+    fun applyDefaults(){
+        include.set(Stability.values().map { s -> s.value() }.filterNot { it == Stability.DEPRECATED.value() })
+    }
+}

modules/openapi-generator-gradle-plugin/src/main/kotlin/org/openapitools/generator/gradle/plugin/tasks/GenerateTask.kt

@@ -155,6 +155,13 @@ open class GenerateTask : DefaultTask() {
     @get:Internal
     val additionalProperties = project.objects.property<Map<String, String>>()
 
+    /**
+     * Sets server variable for server URL template substitution, in the format of name=value,name=value.
+     * You can also have multiple occurrences of this option.
+     */
+    @get:Internal
+    val serverVariables = project.objects.property<Map<String, String>>()
+
     /**
      * Specifies additional language specific primitive types in the format of type1,type2,type3,type3. For example: String,boolean,Boolean,Double.
      */
@@ -573,6 +580,12 @@ open class GenerateTask : DefaultTask() {
                 }
             }
 
+            if (serverVariables.isPresent) {
+                serverVariables.get().forEach { entry ->
+                    configurator.addServerVariable(entry.key, entry.value)
+                }
+            }
+
             if (languageSpecificPrimitives.isPresent) {
                 languageSpecificPrimitives.get().forEach {
                     configurator.addLanguageSpecificPrimitive(it)

modules/openapi-generator-gradle-plugin/src/main/kotlin/org/openapitools/generator/gradle/plugin/tasks/GeneratorsTask.kt

@@ -17,9 +17,11 @@
 package org.openapitools.generator.gradle.plugin.tasks
 
 import org.gradle.api.DefaultTask
+import org.gradle.api.tasks.Internal
 import org.gradle.api.tasks.TaskAction
 import org.gradle.internal.logging.text.StyledTextOutput
 import org.gradle.internal.logging.text.StyledTextOutputFactory
+import org.gradle.kotlin.dsl.listProperty
 import org.openapitools.codegen.CodegenConfigLoader
 import org.openapitools.codegen.CodegenType
 import org.openapitools.codegen.meta.GeneratorMetadata
@@ -35,6 +37,12 @@ import org.openapitools.codegen.meta.Stability
  * @author Jim Schubert
  */
 open class GeneratorsTask : DefaultTask() {
+    /**
+     * A list of stability indexes to include (value: all,beta,stable,experimental,deprecated). Excludes deprecated by default.
+     */
+    @get:Internal
+    val include = project.objects.listProperty<String>()
+
     @Suppress("unused")
     @TaskAction
     fun doWork() {
@@ -45,6 +53,15 @@ open class GeneratorsTask : DefaultTask() {
         StringBuilder().apply {
             val types = CodegenType.values()
 
+            val stabilities = if (include.isPresent) {
+                when {
+                    include.get().contains("all") -> Stability.values().toList()
+                    else -> include.get().map { Stability.forDescription(it) }
+                }
+            } else {
+                Stability.values().filterNot { it == Stability.DEPRECATED }
+            }
+
             append("The following generators are available:")
 
             append(System.lineSeparator())
@@ -56,21 +73,23 @@ open class GeneratorsTask : DefaultTask() {
 
                 generators.filter { it.tag == type }
                         .sortedBy { it.name }
-                        .forEach({ generator ->
+                        .forEach { generator ->
 
                             val meta: GeneratorMetadata? = generator.generatorMetadata
+                            val include = stabilities.contains(meta?.stability)
+                            if (include) {
+                                append("    - ")
+                                append(generator.name)
 
-                            append("    - ")
-                            append(generator.name)
-
-                            meta?.stability?.let {
-                                if (it != Stability.STABLE) {
-                                    append(" (${it.value()})")
+                                meta?.stability?.let {
+                                    if (it != Stability.STABLE) {
+                                        append(" (${it.value()})")
+                                    }
                                 }
-                            }
 
-                            append(System.lineSeparator())
-                        })
+                                append(System.lineSeparator())
+                            }
+                        }
 
                 append(System.lineSeparator())
                 append(System.lineSeparator())

modules/openapi-generator-maven-plugin/examples/java-client.xml

@@ -13,7 +13,7 @@
                 <groupId>org.openapitools</groupId>
                 <artifactId>openapi-generator-maven-plugin</artifactId>
                 <!-- RELEASE_VERSION -->
-                <version>4.1.0</version>
+                <version>4.1.1-SNAPSHOT</version>
                 <!-- /RELEASE_VERSION -->
                 <executions>
                     <execution>
@@ -120,7 +120,12 @@
           <groupId>com.fasterxml.jackson.jaxrs</groupId>
           <artifactId>jackson-jaxrs-json-provider</artifactId>
           <version>${jackson-version}</version>
-        </dependency>
+      </dependency>
+      <dependency>
+          <groupId>org.openapitools</groupId>
+          <artifactId>jackson-databind-nullable</artifactId>
+          <version>${jackson-databind-nullable-version}</version>
+      </dependency>
 
         <!-- Joda time: if you use it -->
         <dependency>
@@ -146,6 +151,7 @@
         <swagger-annotations-version>1.5.8</swagger-annotations-version>
         <jersey-version>2.27</jersey-version>
         <jackson-version>2.8.9</jackson-version>
+        <jackson-databind-nullable-version>0.2.0</jackson-databind-nullable-version>
         <jodatime-version>2.7</jodatime-version>
         <maven-plugin-version>1.0.0</maven-plugin-version>
         <junit-version>4.8.1</junit-version>

modules/openapi-generator-maven-plugin/examples/multi-module/java-client/pom.xml

@@ -19,7 +19,7 @@
                 <groupId>org.openapitools</groupId>
                 <artifactId>openapi-generator-maven-plugin</artifactId>
                 <!-- RELEASE_VERSION -->
-                <version>4.1.0</version>
+                <version>4.1.1-SNAPSHOT</version>
                 <!-- /RELEASE_VERSION -->
                 <dependencies>
                     <dependency>
@@ -133,7 +133,12 @@
           <groupId>com.fasterxml.jackson.jaxrs</groupId>
           <artifactId>jackson-jaxrs-json-provider</artifactId>
           <version>${jackson-version}</version>
-        </dependency>
+      </dependency>
+      <dependency>
+          <groupId>org.openapitools</groupId>
+          <artifactId>jackson-databind-nullable</artifactId>
+          <version>${jackson-databind-nullable-version}</version>
+      </dependency>
 
         <!-- Joda time: if you use it -->
         <dependency>

modules/openapi-generator-maven-plugin/examples/multi-module/pom.xml

@@ -16,6 +16,7 @@
         <swagger-annotations-version>1.5.8</swagger-annotations-version>
         <jersey-version>2.27</jersey-version>
         <jackson-version>2.8.9</jackson-version>
+        <jackson-databind-nullable-version>0.2.0</jackson-databind-nullable-version>
         <jodatime-version>2.7</jodatime-version>
         <maven-plugin-version>1.0.0</maven-plugin-version>
         <junit-version>4.8.1</junit-version>

modules/openapi-generator-maven-plugin/pom.xml

@@ -5,7 +5,7 @@
         <groupId>org.openapitools</groupId>
         <artifactId>openapi-generator-project</artifactId>
         <!-- RELEASE_VERSION -->
-        <version>4.1.0</version>
+        <version>4.1.1-SNAPSHOT</version>
         <!-- /RELEASE_VERSION -->
         <relativePath>../..</relativePath>
     </parent>

modules/openapi-generator-maven-plugin/src/main/java/org/openapitools/codegen/plugin/CodeGenMojo.java

@@ -17,19 +17,8 @@
 
 package org.openapitools.codegen.plugin;
 
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyAdditionalPropertiesKvp;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyImportMappingsKvp;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyInstantiationTypesKvp;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyLanguageSpecificPrimitivesCsv;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyTypeMappingsKvp;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyReservedWordsMappingsKvp;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyAdditionalPropertiesKvpList;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyImportMappingsKvpList;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyInstantiationTypesKvpList;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyLanguageSpecificPrimitivesCsvList;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyTypeMappingsKvpList;
-import static org.openapitools.codegen.config.CodegenConfiguratorUtils.applyReservedWordsMappingsKvpList;
 import static org.apache.commons.lang3.StringUtils.isNotEmpty;
+import static org.openapitools.codegen.config.CodegenConfiguratorUtils.*;
 
 import java.io.File;
 import java.util.HashMap;
@@ -289,6 +278,12 @@ public class CodeGenMojo extends AbstractMojo {
     @Parameter(name = "additionalProperties", property = "openapi.generator.maven.plugin.additionalProperties")
     private List<String> additionalProperties;
 
+    /**
+     * A map of server variable overrides for specs that support server URL templating
+     */
+    @Parameter(name = "serverVariableOverrides", property = "openapi.generator.maven.plugin.serverVariableOverrides")
+    private List<String> serverVariableOverrides;
+
     /**
      * A map of reserved names and how they should be escaped
      */
@@ -615,6 +610,10 @@ public class CodeGenMojo extends AbstractMojo {
                             configurator);
                 }
 
+                if (serverVariableOverrides == null && configOptions.containsKey("server-variables")) {
+                    applyServerVariablesKvp(configOptions.get("server-variables").toString(), configurator);
+                }
+
                 // Retained for backwards-compataibility with configOptions -> reserved-words-mappings
                 if (reservedWordsMappings == null && configOptions.containsKey("reserved-words-mappings")) {
                     applyReservedWordsMappingsKvp(configOptions.get("reserved-words-mappings")
@@ -648,6 +647,10 @@ public class CodeGenMojo extends AbstractMojo {
                 applyAdditionalPropertiesKvpList(additionalProperties, configurator);
             }
 
+            if (serverVariableOverrides != null && (configOptions == null || !configOptions.containsKey("server-variables"))) {
+                applyServerVariablesKvpList(serverVariableOverrides, configurator);
+            }
+
             // Apply Reserved Words Mappings
             if (reservedWordsMappings != null && (configOptions == null || !configOptions.containsKey("reserved-words-mappings"))) {
                 applyReservedWordsMappingsKvpList(reservedWordsMappings, configurator);

modules/openapi-generator-online/pom.xml

@@ -4,7 +4,7 @@
         <groupId>org.openapitools</groupId>
         <artifactId>openapi-generator-project</artifactId>
         <!-- RELEASE_VERSION -->
-        <version>4.1.0</version>
+        <version>4.1.1-SNAPSHOT</version>
         <!-- /RELEASE_VERSION -->
         <relativePath>../..</relativePath>
     </parent>

modules/openapi-generator/pom.xml

@@ -4,7 +4,7 @@
         <groupId>org.openapitools</groupId>
         <artifactId>openapi-generator-project</artifactId>
         <!-- RELEASE_VERSION -->
-        <version>4.1.0</version>
+        <version>4.1.1-SNAPSHOT</version>
         <!-- /RELEASE_VERSION -->
         <relativePath>../..</relativePath>
     </parent>

modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConfig.java

@@ -43,6 +43,8 @@ public interface CodegenConfig {
 
     Map<String, Object> additionalProperties();
 
+    Map<String, String> serverVariableOverrides();
+
     Map<String, Object> vendorExtensions();
 
     String testPackage();

modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenServerVariable.java

@@ -7,4 +7,5 @@ public class CodegenServerVariable {
     public String defaultValue;
     public String description;
     public List<String> enumValues;
+    public String value;
 }

modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java

@@ -97,6 +97,7 @@ public class DefaultCodegen implements CodegenConfig {
     protected String embeddedTemplateDir;
     protected String commonTemplateDir = "_common";
     protected Map<String, Object> additionalProperties = new HashMap<String, Object>();
+    protected Map<String, String> serverVariables = new HashMap<String, String>();
     protected Map<String, Object> vendorExtensions = new HashMap<String, Object>();
     protected List<SupportingFile> supportingFiles = new ArrayList<SupportingFile>();
     protected List<CliOption> cliOptions = new ArrayList<CliOption>();
@@ -240,13 +241,10 @@ public class DefaultCodegen implements CodegenConfig {
         }
 
         if (additionalProperties.containsKey("lambda")) {
-            LOGGER.warn("A property named 'lambda' already exists. Mustache lambdas renamed from 'lambda' to '_lambda'. " +
-                    "You'll likely need to use a custom template, " +
-                    "see https://github.com/OpenAPITools/openapi-generator/blob/master/docs/templating.md. ");
-            additionalProperties.put("_lambda", lambdas);
-        } else {
-            additionalProperties.put("lambda", lambdas);
+            LOGGER.error("A property called 'lambda' already exists in additionalProperties");
+            throw new RuntimeException("A property called 'lambda' already exists in additionalProperties");
         }
+        additionalProperties.put("lambda", lambdas);
     }
 
     // override with any special post-processing for all models
@@ -506,12 +504,12 @@ public class DefaultCodegen implements CodegenConfig {
     public void postProcessParameter(CodegenParameter parameter) {
     }
 
-    //override with any special handling of the entire swagger spec
+    //override with any special handling of the entire OpenAPI spec document
     @SuppressWarnings("unused")
     public void preprocessOpenAPI(OpenAPI openAPI) {
     }
 
-    // override with any special handling of the entire swagger spec
+    // override with any special handling of the entire OpenAPI spec document
     @SuppressWarnings("unused")
     public void processOpenAPI(OpenAPI openAPI) {
     }
@@ -725,6 +723,10 @@ public class DefaultCodegen implements CodegenConfig {
         return additionalProperties;
     }
 
+    public Map<String, String> serverVariableOverrides() {
+        return serverVariables;
+    }
+
     public Map<String, Object> vendorExtensions() {
         return vendorExtensions;
     }
@@ -1825,6 +1827,7 @@ public class DefaultCodegen implements CodegenConfig {
                         } else {
                             // composition
                             addProperties(properties, required, refSchema);
+                            addProperties(allProperties, allRequired, refSchema);
                         }
                     }
 
@@ -4881,41 +4884,54 @@ public class DefaultCodegen implements CodegenConfig {
                 imports.add(codegenParameter.baseType);
             } else {
                 CodegenProperty codegenProperty = fromProperty("property", schema);
-                if (ModelUtils.getAdditionalProperties(schema) != null) {// http body is map
-                    LOGGER.error("Map should be supported. Please report to openapi-generator github repo about the issue.");
-                } else if (codegenProperty != null) {
-                    String codegenModelName, codegenModelDescription;
-
-                    if (codegenModel != null) {
-                        codegenModelName = codegenModel.classname;
-                        codegenModelDescription = codegenModel.description;
-                    } else {
-                        LOGGER.warn("The following schema has undefined (null) baseType. " +
-                                "It could be due to form parameter defined in OpenAPI v2 spec with incorrect consumes. " +
-                                "A correct 'consumes' for form parameters should be " +
-                                "'application/x-www-form-urlencoded' or 'multipart/form-data'");
-                        LOGGER.warn("schema: " + schema);
-                        LOGGER.warn("codegenModel is null. Default to UNKNOWN_BASE_TYPE");
-                        codegenModelName = "UNKNOWN_BASE_TYPE";
-                        codegenModelDescription = "UNKNOWN_DESCRIPTION";
-                    }
-
-                    if (StringUtils.isEmpty(bodyParameterName)) {
-                        codegenParameter.baseName = codegenModelName;
-                    } else {
-                        codegenParameter.baseName = bodyParameterName;
-                    }
 
+                if (codegenProperty != null && codegenProperty.getComplexType() != null && codegenProperty.getComplexType().contains(" | ")) {
+                    List<String> parts = Arrays.asList(codegenProperty.getComplexType().split(" \\| "));
+                    imports.addAll(parts);
+                    String codegenModelName = codegenProperty.getComplexType();
+                    codegenParameter.baseName = codegenModelName;
                     codegenParameter.paramName = toParamName(codegenParameter.baseName);
-                    codegenParameter.baseType = codegenModelName;
+                    codegenParameter.baseType = codegenParameter.baseName;
                     codegenParameter.dataType = getTypeDeclaration(codegenModelName);
-                    codegenParameter.description = codegenModelDescription;
-                    imports.add(codegenParameter.baseType);
+                    codegenParameter.description = codegenProperty.getDescription();
+                } else {
+                    if (ModelUtils.getAdditionalProperties(schema) != null) {// http body is map
+                        LOGGER.error("Map should be supported. Please report to openapi-generator github repo about the issue.");
+                    } else if (codegenProperty != null) {
+                        String codegenModelName, codegenModelDescription;
 
-                    if (codegenProperty.complexType != null) {
-                        imports.add(codegenProperty.complexType);
+                        if (codegenModel != null) {
+                            codegenModelName = codegenModel.classname;
+                            codegenModelDescription = codegenModel.description;
+                        } else {
+                            LOGGER.warn("The following schema has undefined (null) baseType. " +
+                                    "It could be due to form parameter defined in OpenAPI v2 spec with incorrect consumes. " +
+                                    "A correct 'consumes' for form parameters should be " +
+                                    "'application/x-www-form-urlencoded' or 'multipart/form-data'");
+                            LOGGER.warn("schema: " + schema);
+                            LOGGER.warn("codegenModel is null. Default to UNKNOWN_BASE_TYPE");
+                            codegenModelName = "UNKNOWN_BASE_TYPE";
+                            codegenModelDescription = "UNKNOWN_DESCRIPTION";
+                        }
+
+                        if (StringUtils.isEmpty(bodyParameterName)) {
+                            codegenParameter.baseName = codegenModelName;
+                        } else {
+                            codegenParameter.baseName = bodyParameterName;
+                        }
+
+                        codegenParameter.paramName = toParamName(codegenParameter.baseName);
+                        codegenParameter.baseType = codegenModelName;
+                        codegenParameter.dataType = getTypeDeclaration(codegenModelName);
+                        codegenParameter.description = codegenModelDescription;
+                        imports.add(codegenParameter.baseType);
+
+                        if (codegenProperty.complexType != null) {
+                            imports.add(codegenProperty.complexType);
+                        }
                     }
                 }
+
                 setParameterBooleanFlagWithCodegenProperty(codegenParameter, codegenProperty);
                 // set nullable
                 setParameterNullable(codegenParameter, codegenProperty);
@@ -5056,14 +5072,34 @@ public class DefaultCodegen implements CodegenConfig {
         if (variables == null) {
             return Collections.emptyList();
         }
+
+        Map<String, String> variableOverrides = serverVariableOverrides();
+
         List<CodegenServerVariable> codegenServerVariables = new LinkedList<>();
         for (Entry<String, ServerVariable> variableEntry : variables.entrySet()) {
             CodegenServerVariable codegenServerVariable = new CodegenServerVariable();
             ServerVariable variable = variableEntry.getValue();
+            List<String> enums = variable.getEnum();
+
             codegenServerVariable.defaultValue = variable.getDefault();
             codegenServerVariable.description = escapeText(variable.getDescription());
-            codegenServerVariable.enumValues = variable.getEnum();
+            codegenServerVariable.enumValues = enums;
             codegenServerVariable.name = variableEntry.getKey();
+
+            // Sets the override value for a server variable pattern.
+            // NOTE: OpenAPI Specification doesn't prevent multiple server URLs with variables. If multiple objects have the same
+            //       variables pattern, user overrides will apply to _all_ of these patterns. We may want to consider indexed overrides.
+            if (variableOverrides != null && !variableOverrides.isEmpty()) {
+                String value = variableOverrides.getOrDefault(variableEntry.getKey(), variable.getDefault());
+                codegenServerVariable.value = value;
+
+                if (enums != null && !enums.isEmpty() && !enums.contains(value)) {
+                    LOGGER.warn("Variable override of '{}' is not listed in the enum of allowed values ({}).", value, StringUtils.join(enums, ","));
+                }
+            } else {
+                codegenServerVariable.value = variable.getDefault();
+            }
+
             codegenServerVariables.add(codegenServerVariable);
         }
         return codegenServerVariables;

modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultGenerator.java

@@ -207,10 +207,12 @@ public class DefaultGenerator extends AbstractGenerator implements Generator {
             config.vendorExtensions().putAll(openAPI.getExtensions());
         }
 
-        URL url = URLPathUtils.getServerURL(openAPI);
+        // TODO: Allow user to define _which_ servers object in the array to target.
+        // Configures contextPath/basePath according to api document's servers
+        URL url = URLPathUtils.getServerURL(openAPI, config.serverVariableOverrides());
         contextPath = config.escapeText(url.getPath()).replaceAll("/$", ""); // for backward compatibility
         basePathWithoutHost = contextPath;
-        basePath = config.escapeText(URLPathUtils.getHost(openAPI)).replaceAll("/$", "");
+        basePath = config.escapeText(URLPathUtils.getHost(openAPI, config.serverVariableOverrides())).replaceAll("/$", "");
     }
 
     private void configureOpenAPIInfo() {
@@ -548,7 +550,7 @@ public class DefaultGenerator extends AbstractGenerator implements Generator {
                     }
                 });
                 Map<String, Object> operation = processOperations(config, tag, ops, allModels);
-                URL url = URLPathUtils.getServerURL(openAPI);
+                URL url = URLPathUtils.getServerURL(openAPI, config.serverVariableOverrides());
                 operation.put("basePath", basePath);
                 operation.put("basePathWithoutHost", config.encodePath(url.getPath()).replaceAll("/$", ""));
                 operation.put("contextPath", contextPath);
@@ -819,7 +821,7 @@ public class DefaultGenerator extends AbstractGenerator implements Generator {
         Map<String, Object> apis = new HashMap<String, Object>();
         apis.put("apis", allOperations);
 
-        URL url = URLPathUtils.getServerURL(openAPI);
+        URL url = URLPathUtils.getServerURL(openAPI, config.serverVariableOverrides());
 
         bundle.put("openAPI", openAPI);
         bundle.put("basePath", basePath);
@@ -972,6 +974,7 @@ public class DefaultGenerator extends AbstractGenerator implements Generator {
             processOperation(resourcePath, "delete", path.getDelete(), ops, path);
             processOperation(resourcePath, "patch", path.getPatch(), ops, path);
             processOperation(resourcePath, "options", path.getOptions(), ops, path);
+            processOperation(resourcePath, "trace", path.getTrace(), ops, path);
         }
         return ops;
     }
@@ -1191,7 +1194,7 @@ public class DefaultGenerator extends AbstractGenerator implements Generator {
         for (String key : definitions.keySet()) {
             Schema schema = definitions.get(key);
             if (schema == null)
-                throw new RuntimeException("schema cannot be null in processMoels");
+                throw new RuntimeException("schema cannot be null in processModels");
             CodegenModel cm = config.fromModel(key, schema);
             Map<String, Object> mo = new HashMap<String, Object>();
             mo.put("model", cm);

modules/openapi-generator/src/main/java/org/openapitools/codegen/InlineModelResolver.java

@@ -19,6 +19,7 @@ package org.openapitools.codegen;
 
 import io.swagger.v3.core.util.Json;
 import io.swagger.v3.oas.models.*;
+import io.swagger.v3.oas.models.callbacks.Callback;
 import io.swagger.v3.oas.models.media.*;
 import io.swagger.v3.oas.models.parameters.Parameter;
 import io.swagger.v3.oas.models.parameters.RequestBody;
@@ -29,6 +30,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.*;
+import java.util.stream.Collectors;
 
 public class InlineModelResolver {
     private OpenAPI openapi;
@@ -64,7 +66,20 @@ public class InlineModelResolver {
 
         for (String pathname : paths.keySet()) {
             PathItem path = paths.get(pathname);
+            List<Operation> operations = new ArrayList<>(path.readOperations());
+
+            // Include callback operation as well
             for (Operation operation : path.readOperations()) {
+                Map<String, Callback> callbacks = operation.getCallbacks();
+                if (callbacks != null) {
+                    operations.addAll(callbacks.values().stream()
+                            .flatMap(callback -> callback.values().stream())
+                            .flatMap(pathItem -> pathItem.readOperations().stream())
+                            .collect(Collectors.toList()));
+                }
+            }
+
+            for (Operation operation : operations) {
                 flattenRequestBody(openAPI, pathname, operation);
                 flattenParameters(openAPI, pathname, operation);
                 flattenResponses(openAPI, pathname, operation);

modules/openapi-generator/src/main/java/org/openapitools/codegen/config/CodegenConfigurator.java

@@ -67,6 +67,7 @@ public class CodegenConfigurator {
     private Map<String, String> importMappings = new HashMap<>();
     private Set<String> languageSpecificPrimitives = new HashSet<>();
     private Map<String, String> reservedWordMappings = new HashMap<>();
+    private Map<String, String> serverVariables = new HashMap<>();
     private String auth;
 
     public CodegenConfigurator() {
@@ -98,6 +99,12 @@ public class CodegenConfigurator {
         return null;
     }
 
+    public CodegenConfigurator addServerVariable(String key, String value) {
+        this.serverVariables.put(key, value);
+        generatorSettingsBuilder.withServerVariable(key, value);
+        return this;
+    }
+
     public CodegenConfigurator addAdditionalProperty(String key, Object value) {
         this.additionalProperties.put(key, value);
         generatorSettingsBuilder.withAdditionalProperty(key, value);
@@ -146,6 +153,18 @@ public class CodegenConfigurator {
         return this;
     }
 
+    public CodegenConfigurator setServerVariables(Map<String, String> serverVariables) {
+        this.serverVariables = serverVariables;
+        generatorSettingsBuilder.withServerVariables(serverVariables);
+        return this;
+    }
+
+    public CodegenConfigurator setReservedWordsMappings(Map<String, String> reservedWordMappings) {
+        this.reservedWordMappings = reservedWordMappings;
+        generatorSettingsBuilder.withReservedWordMappings(reservedWordMappings);
+        return this;
+    }
+
     public CodegenConfigurator setApiPackage(String apiPackage) {
         generatorSettingsBuilder.withApiPackage(apiPackage);
         return this;
@@ -247,6 +266,7 @@ public class CodegenConfigurator {
 
     public CodegenConfigurator setLanguageSpecificPrimitives(
             Set<String> languageSpecificPrimitives) {
+        this.languageSpecificPrimitives = languageSpecificPrimitives;
         generatorSettingsBuilder.withLanguageSpecificPrimitives(languageSpecificPrimitives);
         return this;
     }
@@ -296,12 +316,6 @@ public class CodegenConfigurator {
         return this;
     }
 
-    public CodegenConfigurator setReservedWordsMappings(Map<String, String> reservedWordMappings) {
-        this.reservedWordMappings = reservedWordMappings;
-        generatorSettingsBuilder.withReservedWordMappings(reservedWordMappings);
-        return this;
-    }
-
     public CodegenConfigurator setSkipOverwrite(boolean skipOverwrite) {
         workflowSettingsBuilder.withSkipOverwrite(skipOverwrite);
         return this;
@@ -459,6 +473,13 @@ public class CodegenConfigurator {
         config.reservedWordsMappings().putAll(generatorSettings.getReservedWordMappings());
         config.additionalProperties().putAll(generatorSettings.getAdditionalProperties());
 
+        Map<String, String> serverVariables = generatorSettings.getServerVariables();
+        if (!serverVariables.isEmpty()) {
+            // This is currently experimental due to vagueness in the specification
+            LOGGER.warn("user-defined server variable support is experimental.");
+            config.serverVariableOverrides().putAll(serverVariables);
+        }
+
         // any other additional properties?
         String templateDir = workflowSettings.getTemplateDir();
         if (templateDir != null) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/config/CodegenConfiguratorUtils.java

@@ -107,6 +107,19 @@ public final class CodegenConfiguratorUtils {
         }
     }
 
+    public static void applyServerVariablesKvpList(List<String> values, CodegenConfigurator configurator) {
+        for(String value : values) {
+            applyServerVariablesKvp(value, configurator);
+        }
+    }
+
+    public static void applyServerVariablesKvp(String values, CodegenConfigurator configurator) {
+        final Map<String, String> map = createMapFromKeyValuePairs(values);
+        for (Map.Entry<String, String> entry : map.entrySet()) {
+            configurator.addServerVariable(entry.getKey(), entry.getValue());
+        }
+    }
+
     public static void applyLanguageSpecificPrimitivesCsvList(List<String> languageSpecificPrimitives, CodegenConfigurator configurator) {
         for(String propString : languageSpecificPrimitives) {
             applyLanguageSpecificPrimitivesCsv(propString, configurator);

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCppCodegen.java

@@ -296,7 +296,7 @@ abstract public class AbstractCppCodegen extends DefaultCodegen implements Codeg
 
     @Override
     public void preprocessOpenAPI(OpenAPI openAPI) {
-        URL url = URLPathUtils.getServerURL(openAPI);
+        URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
         String port = URLPathUtils.getPort(url, "");
         String host = url.getHost();
         if(!port.isEmpty()) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractGoCodegen.java

@@ -389,6 +389,11 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
                     }
                 }
 
+                // import "reflect" package if the parameter is collectionFormat=multi
+                if (param.isCollectionFormatMulti) {
+                    imports.add(createMapping("import", "reflect"));
+                }
+
                 // import "optionals" package if the parameter is optional
                 if (!param.required) {
                     if (!addedOptionalImport) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java

@@ -17,6 +17,7 @@
 
 package org.openapitools.codegen.languages;
 
+import com.google.common.base.CaseFormat;
 import com.google.common.base.Strings;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.Operation;
@@ -417,6 +418,8 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
         importMapping.put("JsonTypeInfo", "com.fasterxml.jackson.annotation.JsonTypeInfo");
         importMapping.put("JsonCreator", "com.fasterxml.jackson.annotation.JsonCreator");
         importMapping.put("JsonValue", "com.fasterxml.jackson.annotation.JsonValue");
+        importMapping.put("JsonIgnore", "com.fasterxml.jackson.annotation.JsonIgnore");
+        importMapping.put("JsonInclude", "com.fasterxml.jackson.annotation.JsonInclude");
         importMapping.put("SerializedName", "com.google.gson.annotations.SerializedName");
         importMapping.put("TypeAdapter", "com.google.gson.TypeAdapter");
         importMapping.put("JsonAdapter", "com.google.gson.annotations.JsonAdapter");
@@ -800,7 +803,13 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
                 }
             }
             return null;
+        } else if (ModelUtils.isObjectSchema(p)) {
+            if (p.getDefault() != null) {
+                return super.toDefaultValue(p);
+            }
+            return null;
         }
+
         return super.toDefaultValue(p);
     }
 
@@ -976,6 +985,9 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
             model.imports.add("ApiModelProperty");
             model.imports.add("ApiModel");
         }
+
+        // store java constant property name in vendor extension, remove dollar sign from the constant name
+        property.vendorExtensions.put("x-java-const-name", CaseFormat.UPPER_CAMEL.to(CaseFormat.UPPER_UNDERSCORE, property.nameInCamelCase.replaceAll("\\$", "")));
     }
 
     @Override

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaJAXRSServerCodegen.java

@@ -110,7 +110,7 @@ public abstract class AbstractJavaJAXRSServerCodegen extends AbstractJavaCodegen
         */
 
         if (!this.additionalProperties.containsKey(SERVER_PORT)) {
-            URL url = URLPathUtils.getServerURL(openAPI);
+            URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
             // 8080 is the default value for a JEE Server:
             this.additionalProperties.put(SERVER_PORT, URLPathUtils.getPort(url, serverPort));
         }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractKotlinCodegen.java

@@ -612,6 +612,7 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
         StringBuilder instantiationType = new StringBuilder(arrayType);
         Schema items = arr.getItems();
         String nestedType = getTypeDeclaration(items);
+        additionalProperties.put("nestedType", nestedType);
         // TODO: We may want to differentiate here between generics and primitive arrays.
         instantiationType.append("<").append(nestedType).append(">");
         return instantiationType.toString();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AspNetCoreServerCodegen.java

@@ -268,7 +268,7 @@ public class AspNetCoreServerCodegen extends AbstractCSharpCodegen {
     @Override
     public void preprocessOpenAPI(OpenAPI openAPI) {
         super.preprocessOpenAPI(openAPI);
-        URL url = URLPathUtils.getServerURL(openAPI);
+        URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
         additionalProperties.put("serverHost", url.getHost());
         additionalProperties.put("serverPort", URLPathUtils.getPort(url, 8080));
     }
@@ -327,6 +327,7 @@ public class AspNetCoreServerCodegen extends AbstractCSharpCodegen {
         supportingFiles.add(new SupportingFile("Solution.mustache", "", packageName + ".sln"));
         supportingFiles.add(new SupportingFile("gitignore", packageFolder, ".gitignore"));
         supportingFiles.add(new SupportingFile("validateModel.mustache", packageFolder + File.separator + "Attributes", "ValidateModelStateAttribute.cs"));
+        supportingFiles.add(new SupportingFile("typeConverter.mustache", packageFolder + File.separator + "Converters", "CustomEnumConverter.cs"));
         supportingFiles.add(new SupportingFile("Project.csproj.mustache", packageFolder, packageName + ".csproj"));
         if (!isLibrary) {
             supportingFiles.add(new SupportingFile("Dockerfile.mustache", packageFolder, "Dockerfile"));

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpNancyFXServerCodegen.java

@@ -359,7 +359,7 @@ public class CSharpNancyFXServerCodegen extends AbstractCSharpCodegen {
 
     @Override
     public void preprocessOpenAPI(final OpenAPI openAPI) {
-        URL url = URLPathUtils.getServerURL(openAPI);
+        URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
         String path = URLPathUtils.getPath(url, "/");
         final String packageContextOption = (String) additionalProperties.get(PACKAGE_CONTEXT);
         additionalProperties.put("packageContext", packageContextOption == null ? sanitizeName(path) : packageContextOption);

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartClientCodegen.java

@@ -118,13 +118,13 @@ public class DartClientCodegen extends DefaultCodegen implements CodegenConfig {
         typeMapping.put("URI", "String");
         typeMapping.put("ByteArray", "String");
 
-        cliOptions.add(new CliOption(BROWSER_CLIENT, "Is the client browser based"));
+        cliOptions.add(new CliOption(BROWSER_CLIENT, "Is the client browser based (for Dart 1.x only)"));
         cliOptions.add(new CliOption(PUB_NAME, "Name in generated pubspec"));
         cliOptions.add(new CliOption(PUB_VERSION, "Version in generated pubspec"));
         cliOptions.add(new CliOption(PUB_DESCRIPTION, "Description in generated pubspec"));
         cliOptions.add(new CliOption(USE_ENUM_EXTENSION, "Allow the 'x-enum-values' extension for enums"));
-        cliOptions.add(new CliOption(CodegenConstants.SOURCE_FOLDER, "source folder for generated code"));
-        cliOptions.add(CliOption.newBoolean(SUPPORT_DART2, "support dart2").defaultValue(Boolean.TRUE.toString()));
+        cliOptions.add(new CliOption(CodegenConstants.SOURCE_FOLDER, "Source folder for generated code"));
+        cliOptions.add(CliOption.newBoolean(SUPPORT_DART2, "Support Dart 2.x").defaultValue(Boolean.TRUE.toString()));
     }
 
     @Override

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/FsharpGiraffeServerCodegen.java

@@ -23,20 +23,14 @@ import org.openapitools.codegen.CodegenConstants;
 import org.openapitools.codegen.CodegenOperation;
 import org.openapitools.codegen.CodegenType;
 import org.openapitools.codegen.SupportingFile;
-import org.openapitools.codegen.CodegenModel;
-import org.openapitools.codegen.CodegenProperty;
 import org.openapitools.codegen.utils.URLPathUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.File;
 import java.net.URL;
-import java.util.Arrays;
 import java.util.Locale;
 import java.util.Map;
-import java.util.Set;
-import java.util.List;
-import java.util.ArrayList;
 
 import static java.util.UUID.randomUUID;
 
@@ -165,7 +159,7 @@ public class FsharpGiraffeServerCodegen extends AbstractFSharpCodegen {
     @Override
     public void preprocessOpenAPI(OpenAPI openAPI) {
         super.preprocessOpenAPI(openAPI);
-        URL url = URLPathUtils.getServerURL(openAPI);
+        URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
         additionalProperties.put("serverHost", url.getHost());
         additionalProperties.put("serverPort", URLPathUtils.getPort(url, 8080));
     }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/GoClientExperimentalCodegen.java

@@ -19,6 +19,8 @@ package org.openapitools.codegen.languages;
 import org.openapitools.codegen.CodegenModel;
 import org.openapitools.codegen.CodegenProperty;
 import org.openapitools.codegen.SupportingFile;
+import org.openapitools.codegen.meta.GeneratorMetadata;
+import org.openapitools.codegen.meta.Stability;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -33,6 +35,10 @@ public class GoClientExperimentalCodegen extends GoClientCodegen {
         super();
         outputFolder = "generated-code/go-experimental";
         embeddedTemplateDir = templateDir = "go-experimental";
+
+        generatorMetadata = GeneratorMetadata.newBuilder(generatorMetadata)
+                .stability(Stability.EXPERIMENTAL)
+                .build();
     }
 
     /**

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellHttpClientCodegen.java

@@ -1065,13 +1065,14 @@ public class HaskellHttpClientCodegen extends DefaultCodegen implements CodegenC
             case "tsv":
                 return "TabSeparated";
             case "ssv":
+            case "space":
                 return "SpaceSeparated";
             case "pipes":
                 return "PipeSeparated";
             case "multi":
                 return "MultiParamArray";
             default:
-                throw new UnsupportedOperationException();
+                throw new UnsupportedOperationException(collectionFormat + " (collection format) not supported");
         }
     }
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellServantCodegen.java

@@ -549,6 +549,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
                 return "(QueryList 'CommaSeparated (" + type + "))";
             case "tsv":
                 return "(QueryList 'TabSeparated (" + type + "))";
+            case "space":
             case "ssv":
                 return "(QueryList 'SpaceSeparated (" + type + "))";
             case "pipes":
@@ -556,7 +557,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
             case "multi":
                 return "(QueryList 'MultiParamArray (" + type + "))";
             default:
-                throw new UnsupportedOperationException();
+                throw new UnsupportedOperationException(collectionFormat + " (collection format) not supported");
         }
     }
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java

@@ -24,6 +24,7 @@ import org.openapitools.codegen.languages.features.BeanValidationFeatures;
 import org.openapitools.codegen.languages.features.GzipFeatures;
 import org.openapitools.codegen.languages.features.PerformBeanValidationFeatures;
 import org.openapitools.codegen.templating.mustache.CaseFormatLambda;
+import org.openapitools.codegen.utils.ModelUtils;
 import org.openapitools.codegen.utils.ProcessUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -583,6 +584,7 @@ public class JavaClientCodegen extends AbstractJavaCodegen
             if (additionalProperties.containsKey("jackson")) {
                 model.imports.add("JsonProperty");
                 model.imports.add("JsonValue");
+                model.imports.add("JsonInclude");
             }
             if (additionalProperties.containsKey("gson")) {
                 model.imports.add("SerializedName");
@@ -623,6 +625,39 @@ public class JavaClientCodegen extends AbstractJavaCodegen
         return objs;
     }
 
+    @Override
+    public Map<String, Object> postProcessModels(Map<String, Object> objs) {
+        objs = super.postProcessModels(objs);
+        if (additionalProperties.containsKey("jackson") && !JERSEY1.equals(getLibrary())) {
+            List<Map<String, String>> imports = (List<Map<String, String>>) objs.get("imports");
+            List<Object> models = (List<Object>) objs.get("models");
+            for (Object _mo : models) {
+                Map<String, Object> mo = (Map<String, Object>) _mo;
+                CodegenModel cm = (CodegenModel) mo.get("model");
+                boolean addImports = false;
+                for (CodegenProperty var : cm.vars) {
+                    boolean isOptionalNullable = Boolean.FALSE.equals(var.required) && Boolean.TRUE.equals(var.isNullable);
+                    // only add JsonNullable and related imports to optional and nullable values
+                    addImports |= isOptionalNullable;
+                    var.getVendorExtensions().put("isJacksonOptionalNullable", isOptionalNullable);
+                }
+                if (addImports) {
+                    cm.imports.add("JsonNullable");
+                    Map<String, String> itemJsonNullable = new HashMap<String, String>();
+                    itemJsonNullable.put("import", "org.openapitools.jackson.nullable.JsonNullable");
+                    imports.add(itemJsonNullable);
+
+                    cm.imports.add("NoSuchElementException");
+                    Map<String, String> itemExc = new HashMap<String, String>();
+                    itemExc.put("import", "java.util.NoSuchElementException");
+                    imports.add(itemExc);
+                }
+            }
+        }
+
+        return objs;
+    }
+
     public void setUseRxJava(boolean useRxJava) {
         this.useRxJava = useRxJava;
         doNotUseRx = false;

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaPKMSTServerCodegen.java

@@ -538,7 +538,7 @@ public class JavaPKMSTServerCodegen extends AbstractJavaCodegen {
             additionalProperties.put(TITLE, this.title);
         }
 
-        URL url = URLPathUtils.getServerURL(openAPI);
+        URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
         this.additionalProperties.put("serverPort", URLPathUtils.getPort(url, 8080));
 
         if (openAPI.getPaths() != null) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaVertXServerCodegen.java

@@ -221,7 +221,7 @@ public class JavaVertXServerCodegen extends AbstractJavaCodegen {
         super.preprocessOpenAPI(openAPI);
 
         // add server port from the swagger file, 8080 by default
-        URL url = URLPathUtils.getServerURL(openAPI);
+        URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
         this.additionalProperties.put("serverPort", URLPathUtils.getPort(url, 8080));
 
         // retrieve api version from swagger file, 1.0.0-SNAPSHOT by default

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KotlinClientCodegen.java

@@ -149,6 +149,7 @@ public class KotlinClientCodegen extends AbstractKotlinCodegen {
         if (CollectionType.LIST.value.equals(collectionType)) {
             typeMapping.put("array", "kotlin.collections.List");
             typeMapping.put("list", "kotlin.collections.List");
+            additionalProperties.put("isList", true);
         }
 
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KotlinSpringServerCodegen.java

@@ -407,7 +407,7 @@ public class KotlinSpringServerCodegen extends AbstractKotlinCodegen
         }
 
         if (!additionalProperties.containsKey(SERVER_PORT)) {
-            URL url = URLPathUtils.getServerURL(openAPI);
+            URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
             this.additionalProperties.put(SERVER_PORT, URLPathUtils.getPort(url, 8080));
         }
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/NodeJSExpressServerCodegen.java

@@ -300,7 +300,7 @@ public class NodeJSExpressServerCodegen extends DefaultCodegen implements Codege
 
     @Override
     public void preprocessOpenAPI(OpenAPI openAPI) {
-        URL url = URLPathUtils.getServerURL(openAPI);
+        URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
         String host =  URLPathUtils.getProtocolAndHost(url);
         String port = URLPathUtils.getPort(url, defaultServerPort) ;
         String basePath = url.getPath();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/NodeJSServerCodegen.java

@@ -358,7 +358,7 @@ public class NodeJSServerCodegen extends DefaultCodegen implements CodegenConfig
 
     @Override
     public void preprocessOpenAPI(OpenAPI openAPI) {
-        URL url = URLPathUtils.getServerURL(openAPI);
+        URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
         String host =  URLPathUtils.getProtocolAndHost(url);
         String port = URLPathUtils.getPort(url, defaultServerPort) ;
         String basePath = url.getPath();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonClientExperimentalCodegen.java

@@ -18,6 +18,9 @@ package org.openapitools.codegen.languages;
 
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
+
+import org.openapitools.codegen.meta.GeneratorMetadata;
+import org.openapitools.codegen.meta.Stability;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -39,6 +42,10 @@ public class PythonClientExperimentalCodegen extends PythonClientCodegen {
         apiTemplateFiles.put("python-experimental/api.mustache", ".py");
         modelDocTemplateFiles.put("python-experimental/model_doc.mustache", ".md");
         modelTemplateFiles.put("python-experimental/model.mustache", ".py");
+
+        generatorMetadata = GeneratorMetadata.newBuilder(generatorMetadata)
+                .stability(Stability.EXPERIMENTAL)
+                .build();
     }
 
     /**

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustServerCodegen.java

@@ -24,9 +24,7 @@ import io.swagger.v3.oas.models.info.Info;
 import io.swagger.v3.oas.models.media.ArraySchema;
 import io.swagger.v3.oas.models.media.FileSchema;
 import io.swagger.v3.oas.models.media.Schema;
-import io.swagger.v3.oas.models.media.StringSchema;
 import io.swagger.v3.oas.models.media.XML;
-import io.swagger.v3.oas.models.parameters.Parameter;
 import io.swagger.v3.oas.models.parameters.RequestBody;
 import io.swagger.v3.oas.models.servers.Server;
 import org.apache.commons.lang3.StringUtils;
@@ -291,7 +289,7 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
         }
         info.setVersion(StringUtils.join(versionComponents, "."));
 
-        URL url = URLPathUtils.getServerURL(openAPI);
+        URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
         additionalProperties.put("serverHost", url.getHost());
         additionalProperties.put("serverPort", URLPathUtils.getPort(url, 80));
     }
@@ -617,10 +615,6 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
         }
 
         for (CodegenParameter param : op.headerParams) {
-            // If a header uses UUIDs, we need to import the UUID package.
-            if (param.dataType.equals(uuidType)) {
-                additionalProperties.put("apiUsesUuid", true);
-            }
             processParam(param, op);
 
             // Give header params a name in camel case. CodegenParameters don't have a nameInCamelCase property.
@@ -756,10 +750,21 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
             }
 
             if (op.authMethods != null) {
+                boolean headerAuthMethods = false;
+
                 for (CodegenSecurity s : op.authMethods) {
                     if (s.isApiKey && s.isKeyInHeader) {
                         s.vendorExtensions.put("x-apiKeyName", toModelName(s.keyParamName));
+                        headerAuthMethods = true;
                     }
+
+                    if (s.isBasicBasic || s.isBasicBearer || s.isOAuth) {
+                        headerAuthMethods = true;
+                    }
+                }
+
+                if (headerAuthMethods) {
+                    op.vendorExtensions.put("hasHeaderAuthMethods", "true");
                 }
             }
         }
@@ -927,7 +932,15 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
             String modelName = entry.getKey();
             CodegenModel model = entry.getValue();
 
+            if (uuidType.equals(model.dataType)) {
+                additionalProperties.put("apiUsesUuid", true);
+            }
+
             for (CodegenProperty prop : model.vars) {
+                if (prop.dataType.equals(uuidType)) {
+                    additionalProperties.put("apiUsesUuid", true);
+                }
+
                 String xmlName = modelXmlNames.get(prop.dataType);
                 if (xmlName != null) {
                     prop.vendorExtensions.put("itemXmlName", xmlName);
@@ -1134,6 +1147,11 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
     private void processParam(CodegenParameter param, CodegenOperation op) {
         String example = null;
 
+        // If a parameter uses UUIDs, we need to import the UUID package.
+        if (param.dataType.equals(uuidType)) {
+            additionalProperties.put("apiUsesUuid", true);
+        }
+
         if (param.isString) {
             param.vendorExtensions.put("formatString", "\\\"{}\\\"");
             example = "\"" + ((param.example != null) ? param.example : "") + "\".to_string()";

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java

@@ -515,8 +515,8 @@ public class SpringCodegen extends AbstractJavaCodegen
             additionalProperties.put(TITLE, this.title);
         }
 
-        if (!additionalProperties.containsKey(SERVER_PORT)) {
-            URL url = URLPathUtils.getServerURL(openAPI);
+        if(!additionalProperties.containsKey(SERVER_PORT)) {
+            URL url = URLPathUtils.getServerURL(openAPI, serverVariableOverrides());
             this.additionalProperties.put(SERVER_PORT, URLPathUtils.getPort(url, 8080));
         }
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptAngularClientCodegen.java

@@ -209,8 +209,9 @@ public class TypeScriptAngularClientCodegen extends AbstractTypeScriptClientCode
         }
 
         // Set the typescript version compatible to the Angular version
-        if (ngVersion.atLeast("7.0.0")) {
-            // Angular v7 requires typescript ">=3.1.1 <3.2.0"
+        if (ngVersion.atLeast("8.0.0")) {
+            additionalProperties.put("tsVersion", ">=3.4.0 <3.6.0");
+        } else if (ngVersion.atLeast("7.0.0")) {
             additionalProperties.put("tsVersion", ">=3.1.1 <3.2.0");
         } else if (ngVersion.atLeast("6.0.0")) {
             additionalProperties.put("tsVersion", ">=2.7.2 and <2.10.0");
@@ -222,7 +223,9 @@ public class TypeScriptAngularClientCodegen extends AbstractTypeScriptClientCode
         }
 
         // Set the rxJS version compatible to the Angular version
-        if (ngVersion.atLeast("7.0.0")) {
+        if (ngVersion.atLeast("8.0.0")) {
+            additionalProperties.put("rxjsVersion", "6.5.0");
+        } else if (ngVersion.atLeast("7.0.0")) {
             additionalProperties.put("rxjsVersion", "6.3.0");
         } else if (ngVersion.atLeast("6.0.0")) {
             additionalProperties.put("rxjsVersion", "6.1.0");
@@ -250,7 +253,10 @@ public class TypeScriptAngularClientCodegen extends AbstractTypeScriptClientCode
         additionalProperties.put("useOldNgPackagr", !ngVersion.atLeast("5.0.0"));
 
         // Specific ng-packagr configuration
-        if (ngVersion.atLeast("7.0.0")) {
+        if (ngVersion.atLeast("8.0.0")) {
+            additionalProperties.put("ngPackagrVersion", "5.4.0");
+            additionalProperties.put("tsickleVersion", "0.35.0");
+        } else if (ngVersion.atLeast("7.0.0")) {
             // compatible versions with typescript version
             additionalProperties.put("ngPackagrVersion", "5.1.0");
             additionalProperties.put("tsickleVersion", "0.34.0");
@@ -268,7 +274,9 @@ public class TypeScriptAngularClientCodegen extends AbstractTypeScriptClientCode
         }
 
         // set zone.js version
-        if (ngVersion.atLeast("5.0.0")) {
+        if (ngVersion.atLeast("8.0.0")) {
+            additionalProperties.put("zonejsVersion", "0.9.1");
+        } else if (ngVersion.atLeast("5.0.0")) {
             // compatible versions to Angular 5+
             additionalProperties.put("zonejsVersion", "0.8.26");
         } else {
@@ -659,3 +667,4 @@ public class TypeScriptAngularClientCodegen extends AbstractTypeScriptClientCode
     }
 
 }
+

modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/URLPathUtils.java

@@ -17,6 +17,7 @@
 
 package org.openapitools.codegen.utils;
 
+import com.google.common.collect.ImmutableMap;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.servers.Server;
 import io.swagger.v3.oas.models.servers.ServerVariable;
@@ -28,9 +29,7 @@ import org.slf4j.LoggerFactory;
 
 import java.net.MalformedURLException;
 import java.net.URL;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
+import java.util.*;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -40,24 +39,28 @@ public class URLPathUtils {
     public static final String LOCAL_HOST = "http://localhost";
     public static final Pattern VARIABLE_PATTERN = Pattern.compile("\\{([^\\}]+)\\}");
 
-    public static URL getServerURL(OpenAPI openAPI) {
+    // TODO: This should probably be moved into generator/workflow type rather than a static like this.
+    public static URL getServerURL(OpenAPI openAPI, Map<String, String> userDefinedVariables) {
         final List<Server> servers = openAPI.getServers();
         if (servers == null || servers.isEmpty()) {
             LOGGER.warn("Server information seems not defined in the spec. Default to {}.", LOCAL_HOST);
             return getDefaultUrl();
         }
         // TODO need a way to obtain all server URLs
-        return getServerURL(servers.get(0));
+        return getServerURL(servers.get(0), userDefinedVariables);
     }
 
-    public static URL getServerURL(final Server server) {
+    public static URL getServerURL(final Server server, final Map<String, String> userDefinedVariables) {
         String url = server.getUrl();
         ServerVariables variables = server.getVariables();
         if (variables == null) {
             variables = new ServerVariables();
         }
+
+        Map<String, String> userVariables = userDefinedVariables == null ? new HashMap<>() : ImmutableMap.copyOf(userDefinedVariables);
+
         if (StringUtils.isNotBlank(url)) {
-            url = extractUrl(server, url, variables);
+            url = extractUrl(server, url, variables, userVariables);
             url = sanitizeUrl(url);
 
             try {
@@ -69,26 +72,37 @@ public class URLPathUtils {
         return getDefaultUrl();
     }
 
-    private static String extractUrl(Server server, String url, ServerVariables variables) {
+    private static String extractUrl(Server server, String url, ServerVariables variables, Map<String, String> userVariables) {
         Set<String> replacedVariables = new HashSet<>();
         Matcher matcher = VARIABLE_PATTERN.matcher(url);
         while (matcher.find()) {
             if (!replacedVariables.contains(matcher.group())) {
-                ServerVariable variable = variables.get(matcher.group(1));
+                String variableName = matcher.group(1);
+                ServerVariable variable = variables.get(variableName);
                 String replacement;
                 if (variable != null) {
-                    if (variable.getDefault() != null) {
-                        replacement = variable.getDefault();
-                    } else if (variable.getEnum() != null && !variable.getEnum().isEmpty()) {
-                        replacement = variable.getEnum().get(0);
-                    } else {
-                        LOGGER.warn("No value found for variable '{}' in server definition '{}', default to empty string.", matcher.group(1), server.getUrl());
-                        replacement = "";
+                    String defaultValue = variable.getDefault();
+                    List<String> enumValues = variable.getEnum() == null ? new ArrayList<>() : variable.getEnum();
+                    if (defaultValue == null && !enumValues.isEmpty()) {
+                       defaultValue = enumValues.get(0);
+                    } else if (defaultValue == null) {
+                        defaultValue = "";
+                    }
+
+                    replacement = userVariables.getOrDefault(variableName, defaultValue);
+
+                    if (!enumValues.isEmpty() && !enumValues.contains(replacement)) {
+                        LOGGER.warn("Variable override of '{}' is not listed in the enum of allowed values ({}).", replacement, StringUtils.join(enumValues, ","));
                     }
                 } else {
-                    LOGGER.warn("No variable '{}' found in server definition '{}', default to empty string.", matcher.group(1), server.getUrl());
-                    replacement = "";
+                    replacement = userVariables.getOrDefault(variableName, "");
                 }
+
+                if (StringUtils.isEmpty(replacement)) {
+                    replacement = "";
+                    LOGGER.warn("No value found for variable '{}' in server definition '{}' and no user override specified, default to empty string.", variableName, server.getUrl());
+                }
+
                 url = url.replace(matcher.group(), replacement);
                 replacedVariables.add(matcher.group());
                 matcher = VARIABLE_PATTERN.matcher(url);
@@ -98,7 +112,7 @@ public class URLPathUtils {
     }
 
     public static String getScheme(OpenAPI openAPI, CodegenConfig config) {
-        URL url = getServerURL(openAPI);
+        URL url = getServerURL(openAPI, config.serverVariableOverrides());
         return getScheme(url, config);
     }
 
@@ -176,11 +190,12 @@ public class URLPathUtils {
      * Return the first complete URL from the OpenAPI specification
      *
      * @param openAPI current OpenAPI specification
+     * @param userDefinedVariables User overrides for server variable templating
      * @return host
      */
-    public static String getHost(OpenAPI openAPI) {
+    public static String getHost(OpenAPI openAPI, final Map<String, String> userDefinedVariables) {
         if (openAPI.getServers() != null && openAPI.getServers().size() > 0) {
-            return sanitizeUrl(getServerURL(openAPI.getServers().get(0)).toString());
+            return sanitizeUrl(getServerURL(openAPI.getServers().get(0), userDefinedVariables).toString());
         }
         return LOCAL_HOST;
     }

modules/openapi-generator/src/main/resources/Java/jackson_annotations.mustache

@@ -0,0 +1,19 @@
+{{!
+ If this is map and items are nullable, make sure that nulls are included.
+ To determine what JsonInclude.Include method to use, consider the following:
+ * If the field is required, always include it, even if it is null.
+ * Else use custom behaviour, IOW use whatever is defined on the object mapper
+ }}
+  @JsonProperty(JSON_PROPERTY_{{vendorExtensions.x-java-const-name}})
+  @JsonInclude({{#isMapContainer}}{{#items.isNullable}}content = JsonInclude.Include.ALWAYS, {{/items.isNullable}}{{/isMapContainer}}value = JsonInclude.Include.{{#required}}ALWAYS{{/required}}{{^required}}USE_DEFAULTS{{/required}})
+  {{#withXml}}
+    {{^isContainer}}
+  @JacksonXmlProperty({{#isXmlAttribute}}isAttribute = true, {{/isXmlAttribute}}{{#xmlNamespace}}namespace="{{xmlNamespace}}", {{/xmlNamespace}}localName = "{{#xmlName}}{{xmlName}}{{/xmlName}}{{^xmlName}}{{baseName}}{{/xmlName}}")
+    {{/isContainer}}
+    {{#isContainer}}
+      {{#isXmlWrapped}}
+  // items.xmlName={{items.xmlName}}
+  @JacksonXmlElementWrapper(useWrapping = {{isXmlWrapped}}, {{#xmlNamespace}}namespace="{{xmlNamespace}}", {{/xmlNamespace}}localName = "{{#items.xmlName}}{{items.xmlName}}{{/items.xmlName}}{{^items.xmlName}}{{items.baseName}}{{/items.xmlName}}")
+      {{/isXmlWrapped}}
+    {{/isContainer}}
+  {{/withXml}}

modules/openapi-generator/src/main/resources/Java/libraries/feign/ApiClient.mustache

@@ -12,6 +12,7 @@ import org.threeten.bp.*;
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
+import org.openapitools.jackson.nullable.JsonNullableModule;
 {{#joda}}
 import com.fasterxml.jackson.datatype.joda.JodaModule;
 {{/joda}}
@@ -177,6 +178,8 @@ public class ApiClient {
     module.addDeserializer(ZonedDateTime.class, CustomInstantDeserializer.ZONED_DATE_TIME);
     objectMapper.registerModule(module);
     {{/threetenbp}}
+    JsonNullableModule jnm = new JsonNullableModule();
+    objectMapper.registerModule(jnm);
     return objectMapper;
   }
 

modules/openapi-generator/src/main/resources/Java/libraries/feign/pom.mustache

@@ -244,6 +244,11 @@
             <artifactId>jackson-databind</artifactId>
             <version>${jackson-databind-version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.openapitools</groupId>
+            <artifactId>jackson-databind-nullable</artifactId>
+            <version>${jackson-databind-nullable-version}</version>
+        </dependency>
         {{#withXml}}
 
             <!-- XML Support -->
@@ -310,6 +315,7 @@
         <feign-version>{{#useFeign10}}10.2.3{{/useFeign10}}{{^useFeign10}}9.7.0{{/useFeign10}}</feign-version>
         <feign-form-version>2.1.0</feign-form-version>
         <jackson-version>2.9.9</jackson-version>
+        <jackson-databind-nullable-version>0.2.0</jackson-databind-nullable-version>
         <jackson-databind-version>2.9.9</jackson-databind-version>
         {{#threetenbp}}
         <jackson-threetenbp-version>2.6.4</jackson-threetenbp-version>

modules/openapi-generator/src/main/resources/Java/libraries/google-api-client/ApiClient.mustache

@@ -4,6 +4,7 @@ import {{apiPackage}}.*;
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
+import org.openapitools.jackson.nullable.JsonNullableModule;
 {{#joda}}
 import com.fasterxml.jackson.datatype.joda.JodaModule;
 {{/joda}}
@@ -53,6 +54,8 @@ public class ApiClient {
         module.addDeserializer(ZonedDateTime.class, CustomInstantDeserializer.ZONED_DATE_TIME);
         objectMapper.registerModule(module);
         {{/threetenbp}}
+        JsonNullableModule jnm = new JsonNullableModule();
+        objectMapper.registerModule(jnm);
         return objectMapper;
     }
 

modules/openapi-generator/src/main/resources/Java/libraries/google-api-client/api.mustache

@@ -104,8 +104,8 @@ public class {{classname}} {
             }
         }{{/queryParams}}{{/hasQueryParams}}
 
-        String url = uriBuilder{{#hasPathParams}}.buildFromMap(uriVariables).toString();{{/hasPathParams}}{{^hasPathParams}}.build().toString();{{/hasPathParams}}
-        GenericUrl genericUrl = new GenericUrl(url);
+        String localVarUrl = uriBuilder{{#hasPathParams}}.buildFromMap(uriVariables).toString();{{/hasPathParams}}{{^hasPathParams}}.build().toString();{{/hasPathParams}}
+        GenericUrl genericUrl = new GenericUrl(localVarUrl);
 
         HttpContent content = {{#isBodyAllowed}}apiClient.new JacksonJsonHttpContent({{#bodyParam}}{{paramName}}{{/bodyParam}}{{^bodyParam}}null{{/bodyParam}}){{/isBodyAllowed}}{{^isBodyAllowed}}null{{/isBodyAllowed}};
         return apiClient.getHttpRequestFactory().buildRequest(HttpMethods.{{httpMethod}}, genericUrl, content).execute();
@@ -135,8 +135,8 @@ public class {{classname}} {
                   }
               }{{/queryParams}}{{/hasQueryParams}}
 
-              String url = uriBuilder{{#hasPathParams}}.buildFromMap(uriVariables).toString();{{/hasPathParams}}{{^hasPathParams}}.build().toString();{{/hasPathParams}}
-              GenericUrl genericUrl = new GenericUrl(url);
+              String localVarUrl = uriBuilder{{#hasPathParams}}.buildFromMap(uriVariables).toString();{{/hasPathParams}}{{^hasPathParams}}.build().toString();{{/hasPathParams}}
+              GenericUrl genericUrl = new GenericUrl(localVarUrl);
 
               HttpContent content = {{#bodyParam}}{{paramName}} == null ?
                 apiClient.new JacksonJsonHttpContent(null) :
@@ -176,8 +176,8 @@ public class {{classname}} {
             }
         }
 
-        String url = uriBuilder{{#hasPathParams}}.buildFromMap(uriVariables).toString();{{/hasPathParams}}{{^hasPathParams}}.build().toString();{{/hasPathParams}}
-        GenericUrl genericUrl = new GenericUrl(url);
+        String localVarUrl = uriBuilder{{#hasPathParams}}.buildFromMap(uriVariables).toString();{{/hasPathParams}}{{^hasPathParams}}.build().toString();{{/hasPathParams}}
+        GenericUrl genericUrl = new GenericUrl(localVarUrl);
 
         HttpContent content = {{#isBodyAllowed}}apiClient.new JacksonJsonHttpContent({{#bodyParam}}{{paramName}}{{/bodyParam}}{{^bodyParam}}null{{/bodyParam}}){{/isBodyAllowed}}{{^isBodyAllowed}}null{{/isBodyAllowed}};
         return apiClient.getHttpRequestFactory().buildRequest(HttpMethods.{{httpMethod}}, genericUrl, content).execute();

modules/openapi-generator/src/main/resources/Java/libraries/google-api-client/pom.mustache

@@ -253,6 +253,11 @@
             <artifactId>jackson-databind</artifactId>
             <version>${jackson-version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.openapitools</groupId>
+            <artifactId>jackson-databind-nullable</artifactId>
+            <version>${jackson-databind-nullable-version}</version>
+        </dependency>
         {{#withXml}}
             <!-- XML processing: Jackson -->
             <dependency>
@@ -303,6 +308,7 @@
         <jersey-common-version>2.25.1</jersey-common-version>
         <jackson-version>2.9.9</jackson-version>
         <jackson-databind-version>2.9.9</jackson-databind-version>
+        <jackson-databind-nullable-version>0.2.0</jackson-databind-nullable-version>
         {{#joda}}
         <jodatime-version>2.9.9</jodatime-version>
         {{/joda}}

modules/openapi-generator/src/main/resources/Java/libraries/jersey2/ApiClient.mustache

@@ -721,6 +721,8 @@ public class ApiClient {
         response = invocationBuilder.method("PATCH", entity);
       } else if ("HEAD".equals(method)) {
         response = invocationBuilder.head();
+      } else if ("TRACE".equals(method)) {
+        response = invocationBuilder.trace();
       } else {
         throw new ApiException(500, "unknown method type " + method);
       }

modules/openapi-generator/src/main/resources/Java/libraries/jersey2/JSON.mustache

@@ -5,6 +5,7 @@ import org.threeten.bp.*;
 {{/threetenbp}}
 import com.fasterxml.jackson.annotation.*;
 import com.fasterxml.jackson.databind.*;
+import org.openapitools.jackson.nullable.JsonNullableModule;
 {{#java8}}
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
 {{/java8}}
@@ -45,6 +46,8 @@ public class JSON implements ContextResolver<ObjectMapper> {
     module.addDeserializer(ZonedDateTime.class, CustomInstantDeserializer.ZONED_DATE_TIME);
     mapper.registerModule(module);
     {{/threetenbp}}
+    JsonNullableModule jnm = new JsonNullableModule();
+    mapper.registerModule(jnm);
   }
 
   /**

modules/openapi-generator/src/main/resources/Java/libraries/jersey2/pom.mustache

@@ -276,6 +276,11 @@
             <artifactId>jackson-databind</artifactId>
             <version>${jackson-databind-version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.openapitools</groupId>
+            <artifactId>jackson-databind-nullable</artifactId>
+            <version>${jackson-databind-nullable-version}</version>
+        </dependency>
         {{#withXml}}
 
             <!-- XML processing: JAXB -->
@@ -357,6 +362,7 @@
         {{/supportJava6}}
         <jackson-version>2.9.9</jackson-version>
         <jackson-databind-version>2.9.9</jackson-databind-version>
+        <jackson-databind-nullable-version>0.2.0</jackson-databind-nullable-version>
         {{#threetenbp}}
         <threetenbp-version>2.6.4</threetenbp-version>
         {{/threetenbp}}

modules/openapi-generator/src/main/resources/Java/libraries/native/ApiClient.mustache

@@ -6,6 +6,7 @@ import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import org.openapitools.jackson.nullable.JsonNullableModule;
 
 import java.net.URI;
 import java.net.URLEncoder;
@@ -151,6 +152,8 @@ public class ApiClient {
     mapper.enable(SerializationFeature.WRITE_ENUMS_USING_TO_STRING);
     mapper.enable(DeserializationFeature.READ_ENUMS_USING_TO_STRING);
     mapper.registerModule(new JavaTimeModule());
+    JsonNullableModule jnm = new JsonNullableModule();
+    mapper.registerModule(jnm);
     URI baseURI = URI.create("{{{basePath}}}");
     scheme = baseURI.getScheme();
     host = baseURI.getHost();

modules/openapi-generator/src/main/resources/Java/libraries/native/generatedAnnotation.mustache

@@ -0,0 +1 @@
+{{^hideGenerationTimestamp}}@javax.annotation.processing.Generated(value = "{{generatorClass}}", date = "{{generatedDate}}"){{/hideGenerationTimestamp}}

modules/openapi-generator/src/main/resources/Java/libraries/native/pom.mustache

@@ -188,6 +188,11 @@
             <artifactId>jackson-datatype-jsr310</artifactId>
             <version>${jackson-version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.openapitools</groupId>
+            <artifactId>jackson-databind-nullable</artifactId>
+            <version>${jackson-databind-nullable-version}</version>
+        </dependency>
 
         <!-- @Nullable annotation -->
         <dependency>
@@ -210,6 +215,7 @@
         <maven.compiler.source>11</maven.compiler.source>
         <maven.compiler.target>11</maven.compiler.target>
         <jackson-version>2.9.9</jackson-version>
+        <jackson-databind-nullable-version>0.2.0</jackson-databind-nullable-version>
         <junit-version>4.12</junit-version>
     </properties>
 </project>

modules/openapi-generator/src/main/resources/Java/libraries/resteasy/ApiClient.mustache

@@ -666,6 +666,8 @@ public class ApiClient {
       response = invocationBuilder.header("X-HTTP-Method-Override", "PATCH").post(entity);
     } else if ("HEAD".equals(method)) {
       response = invocationBuilder.head();
+    } else if ("TRACE".equals(method)) {
+      response = invocationBuilder.trace();
     } else {
       throw new ApiException(500, "unknown method type " + method);
     }

modules/openapi-generator/src/main/resources/Java/libraries/resteasy/JSON.mustache

@@ -2,6 +2,7 @@ package {{invokerPackage}};
 
 import com.fasterxml.jackson.annotation.*;
 import com.fasterxml.jackson.databind.*;
+import org.openapitools.jackson.nullable.JsonNullableModule;
 {{#java8}}
 import com.fasterxml.jackson.datatype.jsr310.*;
 {{/java8}}
@@ -26,6 +27,8 @@ public class JSON implements ContextResolver<ObjectMapper> {
     mapper.enable(SerializationFeature.WRITE_ENUMS_USING_TO_STRING);
     mapper.enable(DeserializationFeature.READ_ENUMS_USING_TO_STRING);
     mapper.setDateFormat(new RFC3339DateFormat());
+    JsonNullableModule jnm = new JsonNullableModule();
+    mapper.registerModule(jnm);
     {{#java8}}
     mapper.registerModule(new JavaTimeModule());
     {{/java8}}

modules/openapi-generator/src/main/resources/Java/libraries/resteasy/pom.mustache

@@ -212,6 +212,11 @@
             <artifactId>jackson-databind</artifactId>
             <version>${jackson-databind-version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.openapitools</groupId>
+            <artifactId>jackson-databind-nullable</artifactId>
+            <version>${jackson-databind-nullable-version}</version>
+        </dependency>
         {{#withXml}}
 
         <!-- XML processing: Jackson -->
@@ -291,6 +296,7 @@
         <resteasy-version>3.1.3.Final</resteasy-version>
         <jackson-version>2.9.9</jackson-version>
         <jackson-databind-version>2.9.9</jackson-databind-version>
+        <jackson-databind-nullable-version>0.2.0</jackson-databind-nullable-version>
         <threetenbp-version>2.6.4</threetenbp-version>
         {{^java8}}
         <jodatime-version>2.9.9</jodatime-version>

modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/ApiClient.mustache

@@ -39,6 +39,7 @@ import com.fasterxml.jackson.datatype.threetenbp.ThreeTenModule;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import org.openapitools.jackson.nullable.JsonNullableModule;
 {{/threetenbp}}
 
 import java.io.BufferedReader;
@@ -661,6 +662,7 @@ public class ApiClient {
         messageConverters.add(new MappingJackson2HttpMessageConverter());
         XmlMapper xmlMapper = new XmlMapper();
         xmlMapper.configure(ToXmlGenerator.Feature.WRITE_XML_DECLARATION, true);
+        xmlMapper.registerModule(new JsonNullableModule());
         messageConverters.add(new MappingJackson2XmlHttpMessageConverter(xmlMapper));
 
         RestTemplate restTemplate = new RestTemplate(messageConverters);
@@ -674,6 +676,7 @@ public class ApiClient {
                 module.addDeserializer(OffsetDateTime.class, CustomInstantDeserializer.OFFSET_DATE_TIME);
                 module.addDeserializer(ZonedDateTime.class, CustomInstantDeserializer.ZONED_DATE_TIME);
                 mapper.registerModule(module);
+                mapper.registerModule(new JsonNullableModule());
             }
         }
         {{/threetenbp}}

modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/pom.mustache

@@ -255,6 +255,11 @@
             <artifactId>jackson-jaxrs-json-provider</artifactId>
             <version>${jackson-version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.openapitools</groupId>
+            <artifactId>jackson-databind-nullable</artifactId>
+            <version>${jackson-databind-nullable-version}</version>
+        </dependency>
         {{#withXml}}
 
             <!-- XML processing: Jackson -->
@@ -306,6 +311,7 @@
         <spring-web-version>4.3.9.RELEASE</spring-web-version>
         <jackson-version>2.9.9</jackson-version>
         <jackson-databind-version>2.9.9</jackson-databind-version>
+        <jackson-databind-nullable-version>0.2.0</jackson-databind-nullable-version>
         {{#joda}}
         <jodatime-version>2.9.9</jodatime-version>
         {{/joda}}

modules/openapi-generator/src/main/resources/Java/libraries/retrofit/CollectionFormats.mustache

@@ -35,6 +35,10 @@ public class CollectionFormats {
         
     }
     
+    public static class SPACEParams extends SSVParams {
+
+    }
+
     public static class SSVParams extends CSVParams {
         
         public SSVParams() {

modules/openapi-generator/src/main/resources/Java/libraries/retrofit2/CollectionFormats.mustache

@@ -35,6 +35,10 @@ public class CollectionFormats {
 
     }
 
+    public static class SPACEParams extends SSVParams {
+
+    }
+
     public static class SSVParams extends CSVParams {
 
         public SSVParams() {

modules/openapi-generator/src/main/resources/Java/libraries/retrofit2/play24/ApiClient.mustache

@@ -8,6 +8,8 @@ import java.util.*;
 import retrofit2.Retrofit;
 import retrofit2.converter.scalars.ScalarsConverterFactory;
 import retrofit2.converter.jackson.JacksonConverterFactory;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.openapitools.jackson.nullable.JsonNullableModule;
 
 import play.libs.Json;
 import play.libs.ws.WSClient;
@@ -68,10 +70,14 @@ public class ApiClient {
             auth.applyToParams(extraQueryParams, extraHeaders);
         }
 
+        ObjectMapper mapper = Json.mapper();
+        JsonNullableModule jnm = new JsonNullableModule();
+        mapper.registerModule(jnm);
+
         return new Retrofit.Builder()
                        .baseUrl(basePath)
                        .addConverterFactory(ScalarsConverterFactory.create())
-                       .addConverterFactory(JacksonConverterFactory.create(Json.mapper()))
+                       .addConverterFactory(JacksonConverterFactory.create(mapper))
                        .callFactory(new Play24CallFactory(wsClient, extraHeaders, extraQueryParams))
                        .addCallAdapterFactory(new Play24CallAdapterFactory())
                        .build()

modules/openapi-generator/src/main/resources/Java/libraries/retrofit2/play25/ApiClient.mustache

@@ -8,6 +8,8 @@ import java.util.*;
 import retrofit2.Retrofit;
 import retrofit2.converter.scalars.ScalarsConverterFactory;
 import retrofit2.converter.jackson.JacksonConverterFactory;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.openapitools.jackson.nullable.JsonNullableModule;
 
 import play.libs.Json;
 import play.libs.ws.WSClient;
@@ -67,10 +69,14 @@ public class ApiClient {
             auth.applyToParams(extraQueryParams, extraHeaders);
         }
 
+        ObjectMapper mapper = Json.mapper();
+        JsonNullableModule jnm = new JsonNullableModule();
+        mapper.registerModule(jnm);
+
         return new Retrofit.Builder()
                        .baseUrl(basePath)
                        .addConverterFactory(ScalarsConverterFactory.create())
-                       .addConverterFactory(JacksonConverterFactory.create(Json.mapper()))
+                       .addConverterFactory(JacksonConverterFactory.create(mapper))
                        .callFactory(new Play25CallFactory(wsClient, extraHeaders, extraQueryParams))
                        .addCallAdapterFactory(new Play25CallAdapterFactory())
                        .build()

modules/openapi-generator/src/main/resources/Java/libraries/retrofit2/play26/ApiClient.mustache

@@ -13,6 +13,7 @@ import retrofit2.Converter;
 import retrofit2.Retrofit;
 import retrofit2.converter.scalars.ScalarsConverterFactory;
 import retrofit2.converter.jackson.JacksonConverterFactory;
+import org.openapitools.jackson.nullable.JsonNullableModule;
 
 import play.libs.Json;
 import play.libs.ws.WSClient;
@@ -89,6 +90,8 @@ public class ApiClient {
         }
         if (defaultMapper == null) {
             defaultMapper = Json.mapper();
+            JsonNullableModule jnm = new JsonNullableModule();
+            defaultMapper.registerModule(jnm);
         }
 
         return new Retrofit.Builder()

modules/openapi-generator/src/main/resources/Java/libraries/retrofit2/pom.mustache

@@ -314,6 +314,11 @@
                 <artifactId>play-java-ws_2.11</artifactId>
                 <version>${play-version}</version>
             </dependency>
+            <dependency>
+                <groupId>org.openapitools</groupId>
+                <artifactId>jackson-databind-nullable</artifactId>
+                <version>${jackson-databind-nullable-version}</version>
+            </dependency>
             {{/play24}}
             {{#play25}}
             <dependency>
@@ -321,6 +326,11 @@
                 <artifactId>play-java-ws_2.11</artifactId>
                 <version>${play-version}</version>
             </dependency>
+            <dependency>
+                <groupId>org.openapitools</groupId>
+                <artifactId>jackson-databind-nullable</artifactId>
+                <version>${jackson-databind-nullable-version}</version>
+            </dependency>
             {{/play25}}
             {{#play26}}
             <dependency>
@@ -333,6 +343,11 @@
                 <artifactId>validation-api</artifactId>
                 <version>1.1.0.Final</version>
             </dependency>
+            <dependency>
+                <groupId>org.openapitools</groupId>
+                <artifactId>jackson-databind-nullable</artifactId>
+                <version>${jackson-databind-nullable-version}</version>
+            </dependency>
             {{/play26}}
         {{/usePlayWS}}
         {{#parcelableModel}}
@@ -373,6 +388,7 @@
         <jackson-version>2.9.9</jackson-version>
         <play-version>2.6.7</play-version>
         {{/play26}}
+        <jackson-databind-nullable-version>0.2.0</jackson-databind-nullable-version>
         {{/usePlayWS}}
         <retrofit-version>2.5.0</retrofit-version>
         {{#useRxJava}}

modules/openapi-generator/src/main/resources/Java/libraries/vertx/ApiClient.mustache

@@ -14,6 +14,7 @@ import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import org.openapitools.jackson.nullable.JsonNullableModule;
 import io.vertx.core.*;
 import io.vertx.core.buffer.Buffer;
 import io.vertx.core.file.AsyncFile;
@@ -77,6 +78,8 @@ public class ApiClient {
         this.objectMapper.enable(DeserializationFeature.READ_ENUMS_USING_TO_STRING);
         this.objectMapper.registerModule(new JavaTimeModule());
         this.objectMapper.setDateFormat(dateFormat);
+        JsonNullableModule jnm = new JsonNullableModule();
+        this.objectMapper.registerModule(jnm);
 
         // Setup authentications (key: authentication name, value: authentication).
         this.authentications = new HashMap<>();{{#authMethods}}{{#isBasic}}{{#isBasicBasic}}

modules/openapi-generator/src/main/resources/Java/libraries/vertx/pom.mustache

@@ -243,6 +243,11 @@
             <artifactId>jackson-databind</artifactId>
             <version>${jackson-databind}</version>
         </dependency>
+        <dependency>
+            <groupId>org.openapitools</groupId>
+            <artifactId>jackson-databind-nullable</artifactId>
+            <version>${jackson-databind-nullable-version}</version>
+        </dependency>
         {{#joda}}
             <dependency>
                 <groupId>com.fasterxml.jackson.datatype</groupId>
@@ -286,6 +291,7 @@
         <swagger-annotations-version>1.5.22</swagger-annotations-version>
         <jackson-version>{{^threetenbp}}2.9.9{{/threetenbp}}{{#threetenbp}}2.6.4{{/threetenbp}}</jackson-version>
         <jackson-databind>{{^threetenbp}}2.9.9{{/threetenbp}}{{#threetenbp}}2.6.4{{/threetenbp}}</jackson-databind>
+        <jackson-databind-nullable-version>0.2.0</jackson-databind-nullable-version>
         <junit-version>4.12</junit-version>
     </properties>
 </project>

modules/openapi-generator/src/main/resources/Java/libraries/webclient/ApiClient.mustache

@@ -3,6 +3,7 @@ package {{invokerPackage}};
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import org.openapitools.jackson.nullable.JsonNullableModule;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.core.ParameterizedTypeReference;
@@ -96,6 +97,8 @@ public class ApiClient {
         mapper.setDateFormat(dateFormat);
         mapper.registerModule(new JavaTimeModule());
         mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+        JsonNullableModule jnm = new JsonNullableModule();
+        mapper.registerModule(jnm);
 
         this.webClient = buildWebClient(mapper);
         this.init();

modules/openapi-generator/src/main/resources/Java/libraries/webclient/pom.mustache

@@ -105,6 +105,11 @@
             <artifactId>jackson-databind</artifactId>
             <version>${jackson-databind-version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.openapitools</groupId>
+            <artifactId>jackson-databind-nullable</artifactId>
+            <version>${jackson-databind-nullable-version}</version>
+        </dependency>
 
         {{#java8}}
             <dependency>
@@ -140,6 +145,7 @@
         <spring-web-version>5.0.7.RELEASE</spring-web-version>
         <jackson-version>2.9.9</jackson-version>
         <jackson-databind-version>2.9.9</jackson-databind-version>
+        <jackson-databind-nullable-version>0.2.0</jackson-databind-nullable-version>
         <junit-version>4.12</junit-version>
         <reactor-version>3.1.8.RELEASE</reactor-version>
         <reactor-netty-version>0.7.8.RELEASE</reactor-netty-version>

modules/openapi-generator/src/main/resources/Java/pojo.mustache

@@ -19,21 +19,6 @@ public class {{classname}} {{#parent}}extends {{{parent}}} {{/parent}}{{#parcela
     {{/mostInnerItems}}
     {{/isContainer}}
     {{/isEnum}}
-  {{#jackson}}
-  public static final String JSON_PROPERTY_{{nameInSnakeCase}} = "{{baseName}}";
-  @JsonProperty(JSON_PROPERTY_{{nameInSnakeCase}})
-  {{#withXml}}
-    {{^isContainer}}
-  @JacksonXmlProperty({{#isXmlAttribute}}isAttribute = true, {{/isXmlAttribute}}{{#xmlNamespace}}namespace="{{xmlNamespace}}", {{/xmlNamespace}}localName = "{{#xmlName}}{{xmlName}}{{/xmlName}}{{^xmlName}}{{baseName}}{{/xmlName}}")
-    {{/isContainer}}
-    {{#isContainer}}
-      {{#isXmlWrapped}}
-  // items.xmlName={{items.xmlName}}
-  @JacksonXmlElementWrapper(useWrapping = {{isXmlWrapped}}, {{#xmlNamespace}}namespace="{{xmlNamespace}}", {{/xmlNamespace}}localName = "{{#items.xmlName}}{{items.xmlName}}{{/items.xmlName}}{{^items.xmlName}}{{items.baseName}}{{/items.xmlName}}")
-      {{/isXmlWrapped}}
-    {{/isContainer}}
-  {{/withXml}}
-  {{/jackson}}
   {{#withXml}}
   {{#isXmlAttribute}}
   @XmlAttribute(name = "{{#xmlName}}{{xmlName}}{{/xmlName}}{{^xmlName}}{{baseName}}{{/xmlName}}")
@@ -56,10 +41,28 @@ public class {{classname}} {{#parent}}extends {{{parent}}} {{/parent}}{{#parcela
   {{/isXmlAttribute}}
   {{/withXml}}
   {{#gson}}
-  public static final String SERIALIZED_NAME_{{nameInSnakeCase}} = "{{baseName}}";
-  @SerializedName(SERIALIZED_NAME_{{nameInSnakeCase}})
+  public static final String SERIALIZED_NAME_{{vendorExtensions.x-java-const-name}} = "{{baseName}}";
+  @SerializedName(SERIALIZED_NAME_{{vendorExtensions.x-java-const-name}})
   {{/gson}}
+  {{#jackson}}
+  public static final String JSON_PROPERTY_{{vendorExtensions.x-java-const-name}} = "{{baseName}}";
+  {{/jackson}}
+  {{#vendorExtensions.isJacksonOptionalNullable}}
+  {{#isContainer}}
+  private JsonNullable<{{{datatypeWithEnum}}}> {{name}} = JsonNullable.<{{{datatypeWithEnum}}}>undefined();
+  {{/isContainer}}
+  {{^isContainer}}
+  private JsonNullable<{{{datatypeWithEnum}}}> {{name}} = JsonNullable.<{{{datatypeWithEnum}}}>{{#defaultValue}}of({{{.}}}){{/defaultValue}}{{^defaultValue}}undefined(){{/defaultValue}};
+  {{/isContainer}}
+  {{/vendorExtensions.isJacksonOptionalNullable}}
+  {{^vendorExtensions.isJacksonOptionalNullable}}
+  {{#isContainer}}
+  private {{{datatypeWithEnum}}} {{name}}{{#required}}{{#defaultValue}} = {{{.}}}{{/defaultValue}}{{/required}}{{^required}} = null{{/required}};
+  {{/isContainer}}
+  {{^isContainer}}
   private {{{datatypeWithEnum}}} {{name}}{{#defaultValue}} = {{{.}}}{{/defaultValue}};
+  {{/isContainer}}
+  {{/vendorExtensions.isJacksonOptionalNullable}}
 
   {{/vars}}
   {{#parcelableModel}}
@@ -84,14 +87,28 @@ public class {{classname}} {{#parent}}extends {{{parent}}} {{/parent}}{{#parcela
   {{/gson}}
   {{/parcelableModel}}
   {{#vars}}
+
   {{^isReadOnly}}
   public {{classname}} {{name}}({{{datatypeWithEnum}}} {{name}}) {
-    this.{{name}} = {{name}};
+    {{#vendorExtensions.isJacksonOptionalNullable}}this.{{name}} = JsonNullable.<{{{datatypeWithEnum}}}>of({{name}});{{/vendorExtensions.isJacksonOptionalNullable}}
+    {{^vendorExtensions.isJacksonOptionalNullable}}this.{{name}} = {{name}};{{/vendorExtensions.isJacksonOptionalNullable}}
     return this;
   }
   {{#isListContainer}}
 
   public {{classname}} add{{nameInCamelCase}}Item({{{items.datatypeWithEnum}}} {{name}}Item) {
+    {{#vendorExtensions.isJacksonOptionalNullable}}
+    if (this.{{name}} == null || !this.{{name}}.isPresent()) {
+      this.{{name}} = JsonNullable.<{{{datatypeWithEnum}}}>of({{{defaultValue}}});
+    }
+    try {
+      this.{{name}}.get().add({{name}}Item);
+    } catch (java.util.NoSuchElementException e) {
+      // this can never happen, as we make sure above that the value is present
+    }
+    return this;
+    {{/vendorExtensions.isJacksonOptionalNullable}}
+    {{^vendorExtensions.isJacksonOptionalNullable}}
     {{^required}}
     if (this.{{name}} == null) {
       this.{{name}} = {{{defaultValue}}};
@@ -99,11 +116,24 @@ public class {{classname}} {{#parent}}extends {{{parent}}} {{/parent}}{{#parcela
     {{/required}}
     this.{{name}}.add({{name}}Item);
     return this;
+    {{/vendorExtensions.isJacksonOptionalNullable}}
   }
   {{/isListContainer}}
   {{#isMapContainer}}
 
   public {{classname}} put{{nameInCamelCase}}Item(String key, {{{items.datatypeWithEnum}}} {{name}}Item) {
+    {{#vendorExtensions.isJacksonOptionalNullable}}
+    if (this.{{name}} == null || !this.{{name}}.isPresent()) {
+      this.{{name}} = JsonNullable.<{{{datatypeWithEnum}}}>of({{{defaultValue}}});
+    }
+    try {
+      this.{{name}}.get().put(key, {{name}}Item);
+    } catch (java.util.NoSuchElementException e) {
+      // this can never happen, as we make sure above that the value is present
+    }
+    return this;
+    {{/vendorExtensions.isJacksonOptionalNullable}}
+    {{^vendorExtensions.isJacksonOptionalNullable}}
     {{^required}}
     if (this.{{name}} == null) {
       this.{{name}} = {{{defaultValue}}};
@@ -111,6 +141,7 @@ public class {{classname}} {{#parent}}extends {{{parent}}} {{/parent}}{{#parcela
     {{/required}}
     this.{{name}}.put(key, {{name}}Item);
     return this;
+    {{/vendorExtensions.isJacksonOptionalNullable}}
   }
   {{/isMapContainer}}
 
@@ -142,13 +173,43 @@ public class {{classname}} {{#parent}}extends {{{parent}}} {{/parent}}{{#parcela
 {{#vendorExtensions.extraAnnotation}}
   {{{vendorExtensions.extraAnnotation}}}
 {{/vendorExtensions.extraAnnotation}}
+{{^vendorExtensions.isJacksonOptionalNullable}}{{#jackson}}{{> jackson_annotations}}{{/jackson}}{{/vendorExtensions.isJacksonOptionalNullable}}
   public {{{datatypeWithEnum}}} {{getter}}() {
+    {{#vendorExtensions.isJacksonOptionalNullable}}
+    {{#isReadOnly}}{{! A readonly attribute doesn't have setter => jackson will set null directly if explicitly returned by API, so make sure we have an empty JsonNullable}}
+    if ({{name}} == null) {
+      {{name}} = JsonNullable.<{{{datatypeWithEnum}}}>{{#defaultValue}}of({{{.}}}){{/defaultValue}}{{^defaultValue}}undefined(){{/defaultValue}};
+    }
+    {{/isReadOnly}}
+    return {{name}}.orElse(null);
+    {{/vendorExtensions.isJacksonOptionalNullable}}
+    {{^vendorExtensions.isJacksonOptionalNullable}}
+    return {{name}};
+    {{/vendorExtensions.isJacksonOptionalNullable}}
+  }
+
+  {{#vendorExtensions.isJacksonOptionalNullable}}
+{{> jackson_annotations}}
+  public JsonNullable<{{{datatypeWithEnum}}}> {{getter}}_JsonNullable() {
     return {{name}};
   }
+  {{/vendorExtensions.isJacksonOptionalNullable}}
+
   {{^isReadOnly}}
+  {{#vendorExtensions.isJacksonOptionalNullable}}
+  @JsonProperty(JSON_PROPERTY_{{vendorExtensions.x-java-const-name}})
+  public void {{setter}}_JsonNullable(JsonNullable<{{{datatypeWithEnum}}}> {{name}}) {
+    this.{{name}} = {{name}};
+  }
+  {{/vendorExtensions.isJacksonOptionalNullable}}
 
   public void {{setter}}({{{datatypeWithEnum}}} {{name}}) {
+    {{#vendorExtensions.isJacksonOptionalNullable}}
+    this.{{name}} = JsonNullable.<{{{datatypeWithEnum}}}>of({{name}});
+    {{/vendorExtensions.isJacksonOptionalNullable}}
+    {{^vendorExtensions.isJacksonOptionalNullable}}
     this.{{name}} = {{name}};
+    {{/vendorExtensions.isJacksonOptionalNullable}}
   }
   {{/isReadOnly}}
 

modules/openapi-generator/src/main/resources/JavaJaxRS/pojo.mustache

@@ -24,7 +24,7 @@ public class {{classname}} {{#parent}}extends {{{parent}}}{{/parent}} {{#seriali
   @SerializedName(SERIALIZED_NAME_{{nameInSnakeCase}})
   {{/gson}}
   {{#isContainer}}
-  private {{{datatypeWithEnum}}} {{name}}{{#required}} = {{{defaultValue}}}{{/required}}{{^required}} = null{{/required}};
+  private {{{datatypeWithEnum}}} {{name}}{{#required}}{{#defaultValue}} = {{{.}}}{{/defaultValue}}{{/required}}{{^required}} = null{{/required}};
   {{/isContainer}}
   {{^isContainer}}
   private {{{datatypeWithEnum}}} {{name}}{{#defaultValue}} = {{{.}}}{{/defaultValue}};

modules/openapi-generator/src/main/resources/Javascript/package.mustache

@@ -11,7 +11,7 @@
     "fs": false
   },
   "dependencies": {
-    "superagent": "3.7.0"
+    "superagent": "5.1.0"
   },
   "devDependencies": {
     "expect.js": "^0.3.1",