Add support for Helidon 4 MP client and server generation (#18627)

* Add support for Helidon 4 MP client and server generation

Signed-off-by: Tim Quinn <tim.quinn@oracle.com>

* Rerun samples generation trying to fix spring jobs

Signed-off-by: Tim Quinn <tim.quinn@oracle.com>

* Update copyright

Signed-off-by: Tim Quinn <tim.quinn@oracle.com>

* Correct the copyright notice

Signed-off-by: Tim Quinn <tim.quinn@oracle.com>

---------

Signed-off-by: Tim Quinn <tim.quinn@oracle.com>

.github/workflows/samples-java-helidon-v3.yaml

@@ -1,14 +1,14 @@
-name: Samples Java Helidon
+name: Samples Java Helidon v3
 
 on:
   push:
     paths:
-      - samples/client/petstore/java-helidon-client/**
+      - samples/client/petstore/java-helidon-client/v3/**
-      - samples/server/petstore/java-helidon-server/**
+      - samples/server/petstore/java-helidon-server/v3/**
   pull_request:
     paths:
-      - samples/client/petstore/java-helidon-client/**
+      - samples/client/petstore/java-helidon-client/v3/**
-      - samples/server/petstore/java-helidon-server/**
+      - samples/server/petstore/java-helidon-server/v3/**
 jobs:
   build:
     name: Build Java Helidon 
@@ -17,10 +17,10 @@ jobs:
       fail-fast: false
       matrix:
         sample:
-          - samples/client/petstore/java-helidon-client/mp
+          - samples/client/petstore/java-helidon-client/v3/mp
-          - samples/client/petstore/java-helidon-client/se
+          - samples/client/petstore/java-helidon-client/v3/se
-          - samples/server/petstore/java-helidon-server/mp
+          - samples/server/petstore/java-helidon-server/v3/mp
-          - samples/server/petstore/java-helidon-server/se
+          - samples/server/petstore/java-helidon-server/v3/se
         version: [17]
     steps:
       - uses: actions/checkout@v4

.github/workflows/samples-java-helidon-v4.yaml

@@ -0,0 +1,39 @@
+name: Samples Java Helidon v4
+
+on:
+  push:
+    paths:
+      - samples/client/petstore/java-helidon-client/v4/**
+      - samples/server/petstore/java-helidon-server/v4/**
+  pull_request:
+    paths:
+      - samples/client/petstore/java-helidon-client/v4/**
+      - samples/server/petstore/java-helidon-server/v4/**
+jobs:
+  build:
+    name: Build Java Helidon 
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        sample:
+          - samples/client/petstore/java-helidon-client/v4/mp
+          - samples/server/petstore/java-helidon-server/v4/mp
+        version: [21]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: ${{ matrix.version }}
+      - name: Cache maven dependencies
+        uses: actions/cache@v4
+        env:
+          cache-name: maven-repository
+        with:
+          path: |
+            ~/.m2
+          key: ${{ runner.os }}-${{ github.job }}-${{ env.cache-name }}-${{ hashFiles('**/pom.xml') }}
+      - name: Build
+        working-directory: ${{ matrix.sample }}
+        run: mvn clean package

.github/workflows/samples-jdk17.yaml

@@ -4,28 +4,28 @@ on:
     paths:
       # clients
       - samples/openapi3/client/petstore/spring-cloud-3/**
-      - samples/client/petstore/java-helidon-client/mp/**
+      - samples/client/petstore/java-helidon-client/v3/mp/**
-      - samples/client/petstore/java-helidon-client/se/**
+      - samples/client/petstore/java-helidon-client/v3/se/**
       - samples/client/petstore/spring-http-interface-reactive/**
       - samples/client/petstore/spring-http-interface/**
       - samples/client/petstore/java/webclient-jakarta/**
       # servers
       - samples/openapi3/server/petstore/springboot-3/**
-      - samples/server/petstore/java-helidon-server/mp/**
+      - samples/server/petstore/java-helidon-server/v3/mp/**
-      - samples/server/petstore/java-helidon-server/se/**
+      - samples/server/petstore/java-helidon-server/v3/se/**
   pull_request:
     paths:
       # clients
       - samples/openapi3/client/petstore/spring-cloud-3/**
-      - samples/client/petstore/java-helidon-client/mp/**
+      - samples/client/petstore/java-helidon-client/v3/mp/**
-      - samples/client/petstore/java-helidon-client/se/**
+      - samples/client/petstore/java-helidon-client/v3/se/**
       - samples/client/petstore/spring-http-interface-reactive/**
       - samples/client/petstore/spring-http-interface/**
       - samples/client/petstore/java/webclient-jakarta/**
       # servers
       - samples/openapi3/server/petstore/springboot-3/**
-      - samples/server/petstore/java-helidon-server/mp/**
+      - samples/server/petstore/java-helidon-server/v3/mp/**
-      - samples/server/petstore/java-helidon-server/se/**
+      - samples/server/petstore/java-helidon-server/v3/se/**
 jobs:
   build:
     name: Build with JDK17
@@ -36,15 +36,15 @@ jobs:
         sample:
           # clients
           - samples/openapi3/client/petstore/spring-cloud-3
-          - samples/client/petstore/java-helidon-client/mp
+          - samples/client/petstore/java-helidon-client/v3/mp/
-          - samples/client/petstore/java-helidon-client/se
+          - samples/client/petstore/java-helidon-client/v3/se
           - samples/client/petstore/spring-http-interface-reactive
           - samples/client/petstore/spring-http-interface
           - samples/client/petstore/java/webclient-jakarta
           # servers
           - samples/openapi3/server/petstore/springboot-3
-          - samples/server/petstore/java-helidon-server/mp
+          - samples/server/petstore/java-helidon-server/v3/mp/
-          - samples/server/petstore/java-helidon-server/se
+          - samples/server/petstore/java-helidon-server/v3/se
           - samples/client/petstore/spring-http-interface-reactive
           - samples/client/petstore/spring-http-interface
     steps:

.github/workflows/samples-jdk21.yaml

@@ -0,0 +1,43 @@
+name: Samples JDK21
+on:
+  push:
+    paths:
+      # clients
+      - samples/client/petstore/java-helidon-client/v4/mp/**
+      # servers
+      - samples/server/petstore/java-helidon-server/v4/mp/**
+  pull_request:
+    paths:
+      # clients
+      - samples/client/petstore/java-helidon-client/v4/mp/**
+      # servers
+      - samples/server/petstore/java-helidon-server/v4/mp/**
+jobs:
+  build:
+    name: Build with JDK21
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        sample:
+          # clients
+          - samples/client/petstore/java-helidon-client/v4/mp/
+          # servers
+          - samples/server/petstore/java-helidon-server/v4/mp/
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: 21
+      - name: Cache maven dependencies
+        uses: actions/cache@v4
+        env:
+          cache-name: maven-repository
+        with:
+          path: |
+            ~/.m2
+          key: ${{ runner.os }}-${{ github.job }}-${{ env.cache-name }}-${{ hashFiles('**/pom.xml') }}
+      - name: Build
+        working-directory: ${{ matrix.sample }}
+        run: mvn clean package

bin/configs/java-helidon-client-mp_3.yaml

@@ -1,8 +1,9 @@
 generatorName: java-helidon-client
 library: mp
-outputDir: samples/client/petstore/java-helidon-client/mp
+outputDir: samples/client/petstore/java-helidon-client/v3/mp
 inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
 additionalProperties:
+  helidonVersion: 3.2.7
   artifactId: petstore-helidon-client-mp
   hideGenerationTimestamp: "true"
   configureAuth: "false"

bin/configs/java-helidon-client-mp_4.yaml

@@ -0,0 +1,14 @@
+generatorName: java-helidon-client
+library: mp
+outputDir: samples/client/petstore/java-helidon-client/v4/mp
+inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
+additionalProperties:
+  helidonVersion: 4.0.8
+  artifactId: petstore-helidon-client-mp
+  hideGenerationTimestamp: "true"
+  configureAuth: "false"
+  build: "all"
+  test: "spock"
+  requiredPropertiesInConstructor: "false"
+  visitable: "true"
+  fullProject: "true"

bin/configs/java-helidon-client-se_3.yaml

@@ -1,8 +1,9 @@
 generatorName: java-helidon-client
 library: se
-outputDir: samples/client/petstore/java-helidon-client/se
+outputDir: samples/client/petstore/java-helidon-client/v3/se
 inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
 additionalProperties:
+  helidonVersion: 3.2.7
   artifactId: petstore-helidon-client-se
   hideGenerationTimestamp: "true"
   configureAuth: "false"

bin/configs/java-helidon-server-mp_3.yaml

@@ -1,9 +1,10 @@
 generatorName: java-helidon-server
 library: mp
-outputDir: samples/server/petstore/java-helidon-server/mp
+outputDir: samples/server/petstore/java-helidon-server/v3/mp
 inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
 templateDir: modules/openapi-generator/src/main/resources/java-helidon/server
 additionalProperties:
+  helidonVersion: 3.2.7
   artifactId: petstore-helidon-server-mp
   hideGenerationTimestamp: "true"
   build: "all"

bin/configs/java-helidon-server-mp_4.yaml

@@ -0,0 +1,13 @@
+generatorName: java-helidon-server
+library: mp
+outputDir: samples/server/petstore/java-helidon-server/v4/mp
+inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
+templateDir: modules/openapi-generator/src/main/resources/java-helidon/server
+additionalProperties:
+  helidonVersion: 4.0.8
+  artifactId: petstore-helidon-server-mp
+  hideGenerationTimestamp: "true"
+  build: "all"
+  test: "spock"
+  useAuth: "false"
+  fullProject: "true"

bin/configs/java-helidon-server-se_3.yaml

@@ -1,9 +1,10 @@
 generatorName: java-helidon-server
 library: se
-outputDir: samples/server/petstore/java-helidon-server/se
+outputDir: samples/server/petstore/java-helidon-server/v3/se
 inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
 templateDir: modules/openapi-generator/src/main/resources/java-helidon/server
 additionalProperties:
+  helidonVersion: 3.2.7
   artifactId: petstore-helidon-server-se
   hideGenerationTimestamp: "true"
   fullProject: "true"

docs/generators/java-helidon-client.md

@@ -40,7 +40,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |fullProject|If set to true, it will generate all files; if set to false, it will only generate API files. If unspecified, the behavior depends on whether a project exists or not: if it does not, same as true; if it does, same as false. Note that test files are never overwritten.| ||
 |generateConstructorWithAllArgs|whether to generate a constructor for all arguments| |false|
 |groupId|groupId in generated pom.xml| |org.openapitools|
-|helidonVersion|Helidon version for generated code| |3.0.1|
+|helidonVersion|Helidon complete version identifier or major version number. The specified exact Helidon release or, if specified as a major version the latest release of that major version,  is used in the generated code.| |Highest released version.|
 |hideGenerationTimestamp|Hides the generation timestamp when files are generated.| |false|
 |ignoreAnyOfInEnum|Ignore anyOf keyword in enum| |false|
 |implicitHeaders|Skip header parameters in the generated API methods using @ApiImplicitParams annotation.| |false|

docs/generators/java-helidon-server.md

@@ -40,14 +40,14 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |generateConstructorWithAllArgs|whether to generate a constructor for all arguments| |false|
 |gradleProject|Whether to generate gradle project instead of maven.| |false|
 |groupId|groupId in generated pom.xml| |org.openapitools|
-|helidonVersion|Helidon version for generated code| |3.0.1|
+|helidonVersion|Helidon complete version identifier or major version number. The specified exact Helidon release or, if specified as a major version the latest release of that major version,  is used in the generated code.| |Highest released version.|
 |hideGenerationTimestamp|Hides the generation timestamp when files are generated.| |false|
 |ignoreAnyOfInEnum|Ignore anyOf keyword in enum| |false|
 |implicitHeaders|Skip header parameters in the generated API methods using @ApiImplicitParams annotation.| |false|
 |implicitHeadersRegex|Skip header parameters that matches given regex in the generated API methods using @ApiImplicitParams annotation. Note: this parameter is ignored when implicitHeaders=true| |null|
 |invokerPackage|root package for generated code| |org.openapitools.server|
 |legacyDiscriminatorBehavior|Set to false for generators with better support for discriminators. (Python, Java, Go, PowerShell, C# have this enabled by default).|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
-|library|library template (sub-template) to use|<dl><dt>**mp**</dt><dd>Helidon MP Server</dd><dt>**se**</dt><dd>Helidon SE Server</dd><dt>**nima**</dt><dd>Helidon NIMA Server</dd><dt>**nima-annotations**</dt><dd>Helidon NIMA Annotations Server</dd></dl>|se|
+|library|library template (sub-template) to use|<dl><dt>**mp**</dt><dd>Helidon MP Server</dd><dt>**se**</dt><dd>Helidon SE Server</dd></dl>|se|
 |licenseName|The name of the license| |Unlicense|
 |licenseUrl|The URL of the license| |http://unlicense.org|
 |modelPackage|package for generated models| |org.openapitools.server.model|

modules/openapi-generator/pom.xml

@@ -299,6 +299,11 @@
             <artifactId>commons-text</artifactId>
             <version>${commons-text.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.apache.maven.resolver</groupId>
+            <artifactId>maven-resolver-util</artifactId>
+            <version>${resolver-util-version}</version>
+        </dependency>
         <dependency>
             <groupId>commons-cli</groupId>
             <artifactId>commons-cli</artifactId>

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

@@ -1,6 +1,6 @@
 /*
- * Copyright 2022 OpenAPI-Generator Contributors (https://openapi-generator.tech)
+ * Copyright 2022, 2024 OpenAPI-Generator Contributors (https://openapi-generator.tech)
- * Copyright (c) 2022 Oracle and/or its affiliates
+ * Copyright (c) 2022, 2024 Oracle and/or its affiliates
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,17 +17,37 @@
 
 package org.openapitools.codegen.languages;
 
+import java.io.File;
+import java.io.IOException;
+import java.net.URI;
+import java.net.URL;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.nio.file.Files;
 import java.nio.file.Paths;
+import java.time.Duration;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.prefs.BackingStoreException;
+import java.util.prefs.Preferences;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
 import io.swagger.v3.oas.models.Operation;
 import io.swagger.v3.oas.models.servers.Server;
+import org.eclipse.aether.util.version.GenericVersionScheme;
+import org.eclipse.aether.version.InvalidVersionSpecificationException;
+import org.eclipse.aether.version.Version;
+import org.eclipse.aether.version.VersionConstraint;
+import org.eclipse.aether.version.VersionScheme;
 import org.openapitools.codegen.CliOption;
 import org.openapitools.codegen.CodegenConstants;
 import org.openapitools.codegen.CodegenOperation;
@@ -52,11 +72,10 @@ public abstract class JavaHelidonCommonCodegen extends AbstractJavaCodegen
     static final String HELIDON_MP = "mp";
     static final String HELIDON_SE = "se";
 
-    static final String HELIDON_NIMA = "nima";
-    static final String HELIDON_NIMA_ANNOTATIONS = "nima-annotations";
-
     static final String MICROPROFILE_ROOT_PACKAGE = "rootJavaEEPackage";
     static final String MICROPROFILE_ROOT_DEP_PREFIX = "x-helidon-rootJavaEEDepPrefix";
+    static final String X_USE_MP_TESTING = "x-helidon-useMpTesting";
+    static final String X_USE_SMALLRYE_JANDEX_PLUGIN = "x-helidon-useSmallRyeJandexPlugin";
     static final String X_HAS_RETURN_TYPE = "x-helidon-hasReturnType";
     static final String X_RETURN_TYPE_EXAMPLE_VALUE = "x-helidon-exampleReturnTypeValue";
     static final String MICROPROFILE_ROOT_PACKAGE_DESC = "Root package name for Java EE";
@@ -66,7 +85,6 @@ public abstract class JavaHelidonCommonCodegen extends AbstractJavaCodegen
     private static final String VALIDATION_ARTIFACT_PREFIX_JAVAX = "";
     private static final String VALIDATION_ARTIFACT_PREFIX_JAKARTA = MICROPROFILE_ROOT_PACKAGE_JAKARTA + ".";
     private static final Map<String, String> EXAMPLE_RETURN_VALUES = new HashMap<String, String>();
-
     // for generated doc
     static final String MICROPROFILE_ROOT_PACKAGE_DEFAULT =
         "Helidon 2.x and earlier: " + MICROPROFILE_ROOT_PACKAGE_JAVAX
@@ -75,9 +93,11 @@ public abstract class JavaHelidonCommonCodegen extends AbstractJavaCodegen
     static final String SERIALIZATION_LIBRARY_JACKSON = "jackson";
     static final String SERIALIZATION_LIBRARY_JSONB = "jsonb";
 
-    public static final String HELIDON_VERSION = "helidonVersion";
     public static final String DEFAULT_HELIDON_VERSION = "3.0.1";
-    static final String HELIDON_VERSION_DESC = "Helidon version for generated code";
+    public static final String HELIDON_VERSION = "helidonVersion";
+    static final String HELIDON_VERSION_DESC = "Helidon complete version identifier or major version number. "
+        + "The specified exact Helidon release or, if specified as a major version the latest release of that major version, "
+        + " is used in the generated code.";
 
     static final String FULL_PROJECT = "fullProject";
     static final String FULL_PROJECT_DESC = "If set to true, it will generate all files; if set to false, " +
@@ -86,8 +106,22 @@ public abstract class JavaHelidonCommonCodegen extends AbstractJavaCodegen
             "are never overwritten.";
 
     private String helidonVersion;
+    private int helidonMajorVersion;
+
     private String rootJavaEEPackage;
     private String rootJavaEEDepPrefix;
+    private String mpTestsGroup;
+    private String mpTestsArtifact;
+    private String jandexGroup;
+    private String jandexArtifact;
+
+    public static String defaultHelidonVersion() {
+        return VersionUtil.instance().defaultVersion();
+    }
+
+    public static String chooseVersion(String requestedVersionPrefix) {
+        return VersionUtil.instance().chooseVersion(requestedVersionPrefix);
+    }
 
     public JavaHelidonCommonCodegen() {
         super();
@@ -97,7 +131,7 @@ public abstract class JavaHelidonCommonCodegen extends AbstractJavaCodegen
         EXAMPLE_RETURN_VALUES.put("map", "Map");
 
         cliOptions.add(new CliOption(HELIDON_VERSION, HELIDON_VERSION_DESC)
-                .defaultValue(DEFAULT_HELIDON_VERSION));
+                .defaultValue("Highest released version."));
         cliOptions.add(new CliOption(MICROPROFILE_ROOT_PACKAGE, MICROPROFILE_ROOT_PACKAGE_DESC)
                 .defaultValue(MICROPROFILE_ROOT_PACKAGE_DEFAULT));
         cliOptions.add(new CliOption(FULL_PROJECT, FULL_PROJECT_DESC)
@@ -128,14 +162,18 @@ public abstract class JavaHelidonCommonCodegen extends AbstractJavaCodegen
                                 HELIDON_VERSION));
             }
             setHelidonVersion(userHelidonVersion);
+
         } else if (!userParentVersion.isEmpty()) {
             setHelidonVersion(userParentVersion);
         } else {
-            setHelidonVersion(DEFAULT_HELIDON_VERSION);
+            setHelidonVersion(VersionUtil.instance().defaultVersion());
         }
 
         additionalProperties.put(HELIDON_VERSION, helidonVersion);
+
         setEEPackageAndDependencies(helidonVersion);
+        setMpTestDependency(helidonVersion);
+        setJandexPluginDependency(helidonVersion);
     }
 
     @Override
@@ -199,8 +237,9 @@ public abstract class JavaHelidonCommonCodegen extends AbstractJavaCodegen
     }
 
     private void setHelidonVersion(String version) {
-        helidonVersion = version;
+        helidonVersion = VersionUtil.instance().chooseVersion(version);
-        setParentVersion(version);
+        setParentVersion(helidonVersion);
+        helidonMajorVersion = VersionUtil.majorVersion(helidonVersion);
     }
 
     private void setEEPackageAndDependencies(String version) {
@@ -217,6 +256,19 @@ public abstract class JavaHelidonCommonCodegen extends AbstractJavaCodegen
                 : VALIDATION_ARTIFACT_PREFIX_JAKARTA);
     }
 
+
+    private void setMpTestDependency(String version) {
+        // The Helidon MP test dependency changed from io.helidon.microprofile.tests:helidon-microprofile-tests-junit5 in 3.x
+        // to io.helidon.microprofile.testing:helidon-microprofile-testing-junit5  in 4.x.
+        additionalProperties.put(X_USE_MP_TESTING, helidonMajorVersion >= 4);
+    }
+
+    private void setJandexPluginDependency(String version) {
+        // The Jandex plug-in GAV changed from org.jboss.jandex:jandex-maven-plugin in 3.x to
+        // io.smallrye:jandex-maven-plugin in 4.x.
+        additionalProperties.put(X_USE_SMALLRYE_JANDEX_PLUGIN, helidonMajorVersion >= 4);
+    }
+
     private String checkAndSelectRootEEPackage(String version) {
         String packagePrefixImpliedByVersion = usesJakartaPackages(version)
             ? MICROPROFILE_ROOT_PACKAGE_JAKARTA
@@ -321,4 +373,206 @@ public abstract class JavaHelidonCommonCodegen extends AbstractJavaCodegen
             return "null";
         }
     }
+
+    /**
+     * Logic for determining the Helidon versions available for user selection, either from helidon.io
+     * or from local preferences or from hard-coded values as a last-chance fallback.
+     */
+    static class VersionUtil {
+
+        private static final String PREFERENCES_KEY = "/io/helidon/openapigenerators";
+        private static final String VERSIONS_KEY = "versions";
+        private static final String HELIDON_VERSIONS_URL = "https://helidon.io/cli-data/versions.xml";
+        private static final Duration CONNECTION_TIMEOUT = Duration.ofSeconds(10);
+        private static final Duration REQUEST_TIMEOUT = Duration.ofSeconds(5);
+
+        private static final System.Logger LOGGER = System.getLogger(VersionUtil.class.getName());
+
+        private static final String DEFAULT_VERSIONS = "<data>\n" +
+                                                       "  <archetypes>\n" +
+                                                       "    <version>2.6.5</version>\n" +
+                                                       "    <version>3.2.6</version>\n" +
+                                                       "    <version>4.0.5</version>\n" +
+                                                       "  </archetypes>\n" +
+                                                       "</data>";
+
+        private static VersionUtil INSTANCE = null;
+        private static ReentrantLock lock = new ReentrantLock();
+
+        static VersionUtil instance() {
+            lock.lock();
+            try {
+                if (INSTANCE == null) {
+                    INSTANCE = new VersionUtil();
+                }
+            } catch (IOException | BackingStoreException ex) {
+                throw new RuntimeException(ex);
+            } finally {
+                lock.unlock();
+            }
+            return INSTANCE;
+        }
+
+        private final List<String> versions;
+
+        private VersionUtil() throws BackingStoreException, IOException {
+            versions = versions();
+        }
+
+        String defaultVersion() {
+            return DEFAULT_HELIDON_VERSION;
+        }
+
+        static int majorVersion(String fullVersion) {
+            return Integer.parseUnsignedInt(fullVersion.substring(0, fullVersion.indexOf('.')));
+        }
+
+        /**
+         * Returns the version that is the "closest" match to the requested version expression from among the known releases,
+         * where the expression is one of the following:
+         * <ul>
+         *     <li>a single major version number (e.g., {@code 4})</li>
+         *     <li>the full exact version to use</li>
+         *     <li>a Maven version range</li>
+         * </ul>
+         *
+         * @param requestedVersion version to search for
+         * @return matching version
+         */
+        String chooseVersion(String requestedVersion) {
+            return chooseVersion(requestedVersion, versions);
+        }
+
+        /**
+         * Returns the version that is the "closest" match to the requested version expression from among the provided
+         * releases, where the expression expression is one of the following:
+         * <ul>
+         *     <li>a single major version number (e.g., {@code 4})</li>
+         *     <li>the full exact version to use</li>
+         *     <li>a Maven version range</li>
+         * </ul>
+         *
+         * @param requestedVersion version to search for
+         * @param candidateVersions releases to consider
+         * @return matching version
+         */
+        String chooseVersion(String requestedVersion, List<String> candidateVersions)  {
+
+            VersionScheme versionScheme = new GenericVersionScheme();
+
+            // If the requested version is a single number then treat it as "highest dot release of this major version".
+            // Otherwise, just create a constraint from the value. That also handles the case where the requested version is
+            // the complete version.
+
+            VersionConstraint requestedConstraint = constraint(versionScheme, requestedVersion);
+            Version bestMatch = null;
+            for (String candidate : candidateVersions) {
+                Version candidateVersion;
+
+                try {
+                    candidateVersion = versionScheme.parseVersion(candidate);
+                } catch (InvalidVersionSpecificationException ex) {
+                   LOGGER.log(System.Logger.Level.WARNING, "Error parsing candidate version '" + candidate + "'", ex);
+                   continue;
+                }
+                if (requestedConstraint.containsVersion(candidateVersion)) {
+                    if (bestMatch == null || bestMatch.compareTo(candidateVersion) <= 0) {
+                        bestMatch = candidateVersion;
+                    }
+                }
+            }
+            return bestMatch != null ? bestMatch.toString() : null;
+        }
+
+        private VersionConstraint constraint(VersionScheme versionScheme, String requestedVersion) {
+            try {
+                int asSingleNumber = Integer.parseUnsignedInt(requestedVersion);
+                try {
+                    return versionScheme.parseVersionConstraint(String.format(Locale.getDefault(),
+                                                                              "[%s,%d-alpha)",
+                                                                              requestedVersion,
+                                                                              asSingleNumber + 1));
+                } catch (InvalidVersionSpecificationException ex) {
+                    throw new RuntimeException("Error preparing constraint for version expression '"
+                                                       + requestedVersion
+                                                       + "' treated as major version " + asSingleNumber,
+                                               ex);
+                }
+            } catch (NumberFormatException nfe) {
+                try {
+                    return versionScheme.parseVersionConstraint(requestedVersion);
+                } catch (InvalidVersionSpecificationException ex) {
+                    throw new RuntimeException("Error parsing version expression '"
+                                                       + requestedVersion
+                                                       + "' as a version constraint",
+                                               ex);
+                }
+            }
+        }
+
+        /**
+         * Retrieves the list of supported versions from the web site or, failing that, local preferences or, failing that,
+         * hard-coded versions.
+         *
+         * @return list of supported versions
+         * @throws IOException in case of error accessing the web site and reading the local file
+         */
+        private static List<String> versions() throws IOException, BackingStoreException {
+
+            HttpClient httpClient = HttpClient.newBuilder()
+                    .connectTimeout(CONNECTION_TIMEOUT)
+                    .build();
+            try {
+
+                HttpRequest req = HttpRequest.newBuilder(URI.create(HELIDON_VERSIONS_URL))
+                        .GET()
+                        .timeout(REQUEST_TIMEOUT)
+                        .build();
+
+                HttpResponse<String> response = httpClient.send(req, HttpResponse.BodyHandlers.ofString());
+
+                Preferences versionPrefs = Preferences.userRoot().node(PREFERENCES_KEY);
+                String versions;
+                if (response.statusCode() == 200) {
+                    versions = response.body();
+                    // Save just-retrieved versions for later off-line use.
+                    versionPrefs.put(VERSIONS_KEY, versions);
+                    versionPrefs.flush();
+                    LOGGER.log(System.Logger.Level.DEBUG, "Saved retrieved versions in preferences");
+                } else {
+                    LOGGER.log(System.Logger.Level.INFO,
+                               "Unable to retrieve versions remotely; using local preferences or hard-wired defaults");
+                    // Try to get versions from preferences.
+                    versions = versionPrefs.get(VERSIONS_KEY, DEFAULT_VERSIONS);
+                }
+
+                return extractVersions(versions);
+
+            } catch (IOException | InterruptedException e) {
+                // Fallback to use the local versions.xml contents.
+                return localDefaultVersions();
+            }
+        }
+
+        private static List<String> localDefaultVersions() throws IOException {
+            URL versionsURL = VersionUtil.class.getResource("versions.xml");
+            if (versionsURL == null) {
+                return extractVersions(DEFAULT_VERSIONS);
+            }
+
+            File versionsFile = new File(versionsURL.getFile());
+            return Files.readAllLines(versionsFile.toPath());
+        }
+
+        private static List<String> extractVersions(String xmlContent) {
+            Pattern versionPattern = Pattern.compile("<version[^>]*>([^>]+)</version>");
+
+            Matcher matcher = versionPattern.matcher(xmlContent);
+            List<String> result = new ArrayList<>();
+            while (matcher.find()) {
+                result.add(matcher.group(1));
+            }
+            return result;
+        }
+    }
 }

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

@@ -1,6 +1,6 @@
 /*
- * Copyright 2022 OpenAPI-Generator Contributors (https://openapi-generator.tech)
+ * Copyright 2022, 2024 OpenAPI-Generator Contributors (https://openapi-generator.tech)
- * Copyright (c) 2022 Oracle and/or its affiliates
+ * Copyright (c) 2022, 2024 Oracle and/or its affiliates
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -104,8 +104,6 @@ public class JavaHelidonServerCodegen extends JavaHelidonCommonCodegen {
 
         supportedLibraries.put(HELIDON_MP, "Helidon MP Server");
         supportedLibraries.put(HELIDON_SE, "Helidon SE Server");
-        supportedLibraries.put(HELIDON_NIMA, "Helidon NIMA Server");
-        supportedLibraries.put(HELIDON_NIMA_ANNOTATIONS, "Helidon NIMA Annotations Server");
 
         CliOption libraryOption = new CliOption(CodegenConstants.LIBRARY, "library template (sub-template) to use");
         libraryOption.setEnum(supportedLibraries);
@@ -224,10 +222,6 @@ public class JavaHelidonServerCodegen extends JavaHelidonCommonCodegen {
             }
             importMapping.put("Handler", "io.helidon.webserver.Handler");
             processSupportingFiles(modifiable, unmodifiable);
-        } else if (isLibrary(HELIDON_NIMA)) {
-            throw new UnsupportedOperationException("Not implemented");
-        } else if (isLibrary(HELIDON_NIMA_ANNOTATIONS)) {
-            throw new UnsupportedOperationException("Not implemented");
         } else {
             LOGGER.error("Unknown library option (-l/--library): {}", getLibrary());
             throw new IllegalArgumentException(

modules/openapi-generator/src/main/resources/java-helidon/client/libraries/mp/pom.mustache

@@ -85,8 +85,14 @@
                 </executions>
             </plugin>
             <plugin>
+{{^x-helidon-useSmallRyeJandexPlugin}}
                 <groupId>org.jboss.jandex</groupId>
                 <artifactId>jandex-maven-plugin</artifactId>
+{{/x-helidon-useSmallRyeJandexPlugin}}
+{{#x-helidon-useSmallRyeJandexPlugin}}
+                <groupId>io.smallrye</groupId>
+                <artifactId>jandex-maven-plugin</artifactId>
+{{/x-helidon-useSmallRyeJandexPlugin}}
                 <executions>
                     <execution>
                         <id>make-index</id>

modules/openapi-generator/src/main/resources/java-helidon/server/libraries/mp/pom.mustache

@@ -68,11 +68,20 @@
             <artifactId>junit-jupiter-api</artifactId>
             <scope>test</scope>
         </dependency>
+{{^x-helidon-useMpTesting}}
         <dependency>
             <groupId>io.helidon.microprofile.tests</groupId>
             <artifactId>helidon-microprofile-tests-junit5</artifactId>
             <scope>test</scope>
         </dependency>
+{{/x-helidon-useMpTesting}}
+{{#x-helidon-useMpTesting}}
+        <dependency>
+            <groupId>io.helidon.microprofile.testing</groupId>
+            <artifactId>helidon-microprofile-testing-junit5</artifactId>
+            <scope>test</scope>
+        </dependency>
+{{/x-helidon-useMpTesting}}
     </dependencies>
 
     <build>
@@ -87,8 +96,14 @@
                 </executions>
             </plugin>
             <plugin>
+{{^x-helidon-useSmallRyeJandexPlugin}}
                 <groupId>org.jboss.jandex</groupId>
                 <artifactId>jandex-maven-plugin</artifactId>
+{{/x-helidon-useSmallRyeJandexPlugin}}
+{{#x-helidon-useSmallRyeJandexPlugin}}
+                <groupId>io.smallrye</groupId>
+                <artifactId>jandex-maven-plugin</artifactId>
+{{/x-helidon-useSmallRyeJandexPlugin}}
                 <executions>
                     <execution>
                         <id>make-index</id>

modules/openapi-generator/src/test/java/org/openapitools/codegen/java/helidon/JavaHelidonCommonCodegenPackagePrefixTest.java

@@ -1,6 +1,6 @@
 /*
- * Copyright 2022 OpenAPI-Generator Contributors (https://openapi-generator.tech)
+ * Copyright 2022, 2024 OpenAPI-Generator Contributors (https://openapi-generator.tech)
- * Copyright (c) 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2022, 2024 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,7 +26,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-import org.junit.jupiter.api.Assertions;
+import org.junit.Assert;
 import org.openapitools.codegen.CodegenConstants;
 import org.openapitools.codegen.DefaultGenerator;
 import org.openapitools.codegen.TestUtils;
@@ -44,7 +44,7 @@ public class JavaHelidonCommonCodegenPackagePrefixTest {
   private static final String EXCEPTION_MESSAGE_FRAGMENT = "namespace but options specified";
 
   // The generated SE client does not depend on the jakarta/javax imports, so no need to test it.
-  private static final List<List<String>> GENERATOR_LIBRARY_PAIRS = new ArrayList<List<String>>() {
+  private static final List<List<String>> GENERATOR_LIBRARY_PAIRS = new ArrayList<>() {
       {
           add(listOf("java-helidon-client", "mp"));
           add(listOf("java-helidon-server", "se"));
@@ -76,10 +76,25 @@ public class JavaHelidonCommonCodegenPackagePrefixTest {
                                        String explicitPrefix,
                                        String generatorName,
                                        String libraryName) {
-    IllegalArgumentException e = Assertions.assertThrows(IllegalArgumentException.class,
+    IllegalArgumentException e = Assert.assertThrows("Run invalid combo: " + assertMsg(explicitHelidonVersion,
+                                                                                       explicitPrefix,
+                                                                                       generatorName,
+                                                                                       libraryName),
+                                                     IllegalArgumentException.class,
         () -> runTest(explicitHelidonVersion, explicitPrefix, generatorName, libraryName));
-    Assertions.assertTrue(e.getMessage().contains(EXCEPTION_MESSAGE_FRAGMENT),
+    Assert.assertTrue("Exception message for " + assertMsg(explicitHelidonVersion,
-      "Exception message '" + e.getMessage() + "' contains '" + EXCEPTION_MESSAGE_FRAGMENT + "'");
+                                                           explicitPrefix,
+                                                           generatorName,
+                                                           libraryName)
+                              + "'" + e.getMessage() + "' containing '" + EXCEPTION_MESSAGE_FRAGMENT + "'",
+        e.getMessage().contains(EXCEPTION_MESSAGE_FRAGMENT));
+  }
+
+  private static String assertMsg(String explicitHelidonVersion, String explicitPrefix, String generatorName, String libraryName) {
+    return "Explicit version: " + (explicitHelidonVersion == null ? "null" : explicitHelidonVersion)
+            + ", explicit prefix: " + (explicitPrefix == null ? "null" : explicitPrefix)
+            + ", generatorName: " + generatorName
+            + ", libraryName: " + libraryName;
   }
 
   @DataProvider(name = "valid")

modules/openapi-generator/src/test/java/org/openapitools/codegen/java/helidon/JavaHelidonCommonCodegenTest.java

@@ -1,6 +1,6 @@
 /*
- * Copyright 2022 OpenAPI-Generator Contributors (https://openapi-generator.tech)
+ * Copyright 2022, 2024 OpenAPI-Generator Contributors (https://openapi-generator.tech)
- * Copyright (c) 2022 Oracle and/or its affiliates
+ * Copyright (c) 2022, 2024 Oracle and/or its affiliates
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,73 +26,110 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 
-import org.junit.jupiter.api.Assertions;
+import org.junit.Assert;
 import org.openapitools.codegen.CodegenConstants;
 import org.openapitools.codegen.DefaultGenerator;
 import org.openapitools.codegen.TestUtils;
 import org.openapitools.codegen.config.CodegenConfigurator;
+import org.openapitools.codegen.languages.JavaHelidonCommonCodegen;
 import org.testng.annotations.BeforeMethod;
 import org.testng.annotations.Test;
 
 public class JavaHelidonCommonCodegenTest {
 
-    private DefaultGenerator generator;
+    private DefaultGenerator mpServerGenerator;
-    private CodegenConfigurator configurator;
+    private DefaultGenerator mpClientGenerator;
-    private String outputDir;
+    private CodegenConfigurator mpServerConfigurator;
+    private CodegenConfigurator mpClientConfigurator;
+    private String mpServerOutputDir;
+    private String mpClientOutputDir;
 
     @BeforeMethod
     public void setup() throws IOException {
-        File output = Files.createTempDirectory("test").toFile();
+        File mpServerOutput = Files.createTempDirectory("testMpServer").toFile();
-        output.deleteOnExit();
+        mpServerOutput.deleteOnExit();
-        outputDir = output.getAbsolutePath().replace('\\', '/');
+        mpServerOutputDir = mpServerOutput.getAbsolutePath().replace('\\', '/');
 
-        configurator = new CodegenConfigurator()
+        File mpClientOutput = Files.createTempDirectory("testMpClient").toFile();
+        mpClientOutputDir = mpClientOutput.getAbsolutePath().replace('\\', '/');
+
+        mpServerConfigurator = new CodegenConfigurator()
                 .setGeneratorName("java-helidon-server")
                 .setLibrary("mp")
                 .setInputSpec("src/test/resources/3_0/helidon/petstore-for-testing.yaml")
-                .setOutputDir(outputDir);
+                .setOutputDir(mpServerOutputDir);
 
-        generator = new DefaultGenerator();
+        mpClientConfigurator = new CodegenConfigurator()
+                .setGeneratorName("java-helidon-client")
+                .setLibrary("mp")
+                .setInputSpec("src/test/resources/3_0/helidon/petstore-for-testing.yaml")
+                .setOutputDir(mpClientOutputDir);
+
+
+        mpServerGenerator = new DefaultGenerator();
+        mpClientGenerator = new DefaultGenerator();
     }
 
     @Test
     public void defaultVersionTest() {
-        runVersionTest(null, null);
+        runServerVersionTest(null, null);
     }
 
     @Test
     public void customHelidonVersionOnlyTest() {
-        runVersionTest("3.0.0", null);
+        runServerVersionTest("3.0.0", null);
+    }
+
+    @Test
+    void customHelidonMajorVersionOnlyTest() {
+        runServerVersionTest("3", null);
     }
 
     @Test
     public void customParentVersionOnlyTest() {
-        runVersionTest(null, "3.0.0");
+        runServerVersionTest(null, "3.0.0");
     }
 
     @Test
     public void bothEqualsVersionTest() {
-        runVersionTest("3.0.0", "3.0.0");
+        runServerVersionTest("3.0.0", "3.0.0");
     }
 
     @Test
     public void bothNotEqualsVersionTest() {
-        IllegalArgumentException e = Assertions.assertThrows(IllegalArgumentException.class,() -> runVersionTest("1.0.0", "2.0.0"));
+        IllegalArgumentException e = Assert.assertThrows(IllegalArgumentException.class,() -> runServerVersionTest("1.0.0", "2.0.0"));
-        Assertions.assertEquals(
+        Assert.assertEquals(
                 "Both parentVersion and helidonVersion properties were set with different value.",
                 e.getMessage());
     }
 
-    private void runVersionTest(String helidonVersion, String parentVersion) {
+    @Test
+    void customHelidonVersionOnlyClientTest() {
+        runClientVersionTest("4", null);
+    }
+
+    private void runServerVersionTest(String helidonVersion, String parentVersion) {
+        runVersionTest(helidonVersion, parentVersion, mpServerGenerator, mpServerConfigurator, mpServerOutputDir);
+    }
+
+    private void runClientVersionTest(String helidonVersion, String parentVersion) {
+        runVersionTest(helidonVersion, parentVersion, mpClientGenerator, mpClientConfigurator, mpClientOutputDir);
+    }
+
+    private void runVersionTest(String helidonVersion,
+                                String parentVersion,
+                                DefaultGenerator generator,
+                                CodegenConfigurator configurator,
+                                String outputDir) {
         Map<String, Object> additionalProperties = new HashMap<>();
-        String expected = "3.0.1";
+        String expected = JavaHelidonCommonCodegen.defaultHelidonVersion();
         if (parentVersion != null) {
             additionalProperties.put(CodegenConstants.PARENT_VERSION, parentVersion);
-            expected = parentVersion;
+            expected = JavaHelidonCommonCodegen.chooseVersion(parentVersion);
         }
         if (helidonVersion != null) {
             additionalProperties.put("helidonVersion", helidonVersion);
-            expected = helidonVersion;
+            expected = JavaHelidonCommonCodegen.chooseVersion(helidonVersion);
         }
         generator.opts(configurator.setAdditionalProperties(additionalProperties)
                                        .toClientOptInput());

modules/openapi-generator/src/test/java/org/openapitools/codegen/languages/HelidonCommonCodegenTest.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2024 OpenAPI-Generator Contributors (https://openapi-generator.tech)
+ * Copyright (c) 2024 Oracle and/or its affiliates.
+ *
+ * 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.codegen.languages;
+
+import java.util.List;
+
+import org.junit.Assert;
+import org.testng.annotations.Test;
+
+// This test class is in this package, not org.openapitools.codegen.java.helidon, so it can refer to elements of
+// JavaHelidonCommonCodegen without making them public; package-private is sufficient and we don't want to expose those methods
+// more broadly.
+class HelidonCommonCodegenTest {
+
+    @Test
+    void checkMajorVersionMatch() {
+        Assert.assertEquals("1.2.3",
+                            JavaHelidonCommonCodegen.VersionUtil.instance().chooseVersion("1",
+                                                                                          List.of("3.2.1",
+                                                                                                  "3.2.0",
+                                                                                                  "2.0.4",
+                                                                                                  "1.2.3",
+                                                                                                  "1.2.2",
+                                                                                                  "1.1.0")));
+    }
+
+    @Test
+    void checkExactMatch() {
+        Assert.assertEquals("1.2.2",
+                            JavaHelidonCommonCodegen.VersionUtil.instance().chooseVersion("1.2.2",
+                                                                                          List.of("3.2.1",
+                                                                                                  "3.2.0",
+                                                                                                  "2.0.4",
+                                                                                                  "1.2.3",
+                                                                                                  "1.2.2",
+                                                                                                  "1.1.0")));
+    }
+}

modules/openapi-generator/src/test/resources/3_0/helidon/petstore-for-testing.yaml

@@ -279,7 +279,7 @@ paths:
         - petstore_auth:
             - 'write:pets'
             - 'read:pets'
-  '/pet/{petId}/uploadImage':
+  '/pet/{petId}/{petDate}/uploadImage':
     post:
       tags:
         - pet

pom.xml

@@ -1250,6 +1250,7 @@
         <openrewrite.version>8.8.3</openrewrite.version>
         <pmd-plugin.version>3.12.0</pmd-plugin.version>
         <reflections.version>0.10.2</reflections.version>
+        <resolver-util-version>1.9.18</resolver-util-version>
         <rxgen.version>1.4</rxgen.version>
         <scala-maven-plugin.version>4.6.1</scala-maven-plugin.version>
         <slf4j.version>1.7.36</slf4j.version>

samples/client/petstore/java-helidon-client/v3/mp/pom.xml

@@ -6,7 +6,7 @@
     <parent>
         <groupId>io.helidon.applications</groupId>
         <artifactId>helidon-mp</artifactId>
-        <version>3.0.1</version>
+        <version>3.2.7</version>
         <relativePath/>
     </parent>
     <artifactId>petstore-helidon-client-mp</artifactId>