rest-template: allow array parameters in path using collectionFormat (#2177)

* 2125: java-resttemplate: Support collection formats in pathParams

* run ./bin/java-petstore-resttemplate.sh
run ./bin/java-petstore-resttemplate-withxml.sh

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

@@ -382,6 +382,28 @@ public class ApiClient {
         }
     }
 
+    /**
+    * Formats the specified collection path parameter to a string value.
+    *
+    * @param collectionFormat The collection format of the parameter.
+    * @param value The value of the parameter.
+    * @return String representation of the parameter
+    */
+    public String collectionPathParameterToString(CollectionFormat collectionFormat, Collection<? extends CharSequence> values) {
+        // create the value based on the collection format
+        if (CollectionFormat.MULTI.equals(collectionFormat)) {
+            // not valid for path params
+            return parameterToString(values);
+        }
+
+        // collectionFormat is assumed to be "csv" by default
+        if(collectionFormat == null) {
+            collectionFormat = CollectionFormat.CSV;
+        }
+
+        return collectionFormat.collectionToString(values);
+    }
+
     /**
      * Converts a parameter to a {@link MultiValueMap} for use in REST requests
      * @param collectionFormat The format to convert to

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

@@ -71,7 +71,7 @@ public class {{classname}} {
         {{/required}}{{/allParams}}{{#hasPathParams}}
         // create path and map variables
         final Map<String, Object> uriVariables = new HashMap<String, Object>();{{#pathParams}}
-        uriVariables.put("{{baseName}}", {{{paramName}}});{{/pathParams}}{{/hasPathParams}}
+        uriVariables.put("{{baseName}}", {{#collectionFormat}}apiClient.collectionPathParameterToString(ApiClient.CollectionFormat.valueOf("{{{collectionFormat}}}".toUpperCase()), {{{paramName}}}){{/collectionFormat}}{{^collectionFormat}}{{{paramName}}}{{/collectionFormat}});{{/pathParams}}{{/hasPathParams}}
         String {{localVariablePrefix}}path = UriComponentsBuilder.fromPath("{{{path}}}"){{#hasPathParams}}.buildAndExpand(uriVariables){{/hasPathParams}}{{^hasPathParams}}.build(){{/hasPathParams}}.toUriString();
 
         final MultiValueMap<String, String> {{localVariablePrefix}}queryParams = new LinkedMultiValueMap<String, String>();

samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/ApiClient.java

@@ -371,6 +371,28 @@ public class ApiClient {
         }
     }
 
+    /**
+    * Formats the specified collection path parameter to a string value.
+    *
+    * @param collectionFormat The collection format of the parameter.
+    * @param value The value of the parameter.
+    * @return String representation of the parameter
+    */
+    public String collectionPathParameterToString(CollectionFormat collectionFormat, Collection<? extends CharSequence> values) {
+        // create the value based on the collection format
+        if (CollectionFormat.MULTI.equals(collectionFormat)) {
+            // not valid for path params
+            return parameterToString(values);
+        }
+
+        // collectionFormat is assumed to be "csv" by default
+        if(collectionFormat == null) {
+            collectionFormat = CollectionFormat.CSV;
+        }
+
+        return collectionFormat.collectionToString(values);
+    }
+
     /**
      * Converts a parameter to a {@link MultiValueMap} for use in REST requests
      * @param collectionFormat The format to convert to

samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/ApiClient.java

@@ -366,6 +366,28 @@ public class ApiClient {
         }
     }
 
+    /**
+    * Formats the specified collection path parameter to a string value.
+    *
+    * @param collectionFormat The collection format of the parameter.
+    * @param value The value of the parameter.
+    * @return String representation of the parameter
+    */
+    public String collectionPathParameterToString(CollectionFormat collectionFormat, Collection<? extends CharSequence> values) {
+        // create the value based on the collection format
+        if (CollectionFormat.MULTI.equals(collectionFormat)) {
+            // not valid for path params
+            return parameterToString(values);
+        }
+
+        // collectionFormat is assumed to be "csv" by default
+        if(collectionFormat == null) {
+            collectionFormat = CollectionFormat.CSV;
+        }
+
+        return collectionFormat.collectionToString(values);
+    }
+
     /**
      * Converts a parameter to a {@link MultiValueMap} for use in REST requests
      * @param collectionFormat The format to convert to