Fix issue #907 by ensuring the parameters is properly "exploded"

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

@@ -120,8 +120,10 @@ public class {{classname}} {
         final MultiValueMap<String, String> localVarCookieParams = new LinkedMultiValueMap<String, String>();
         final MultiValueMap<String, Object> localVarFormParams = new LinkedMultiValueMap<String, Object>();{{#hasQueryParams}}
 
-        {{#queryParams}}localVarQueryParams.putAll(apiClient.parameterToMultiValueMap({{#collectionFormat}}ApiClient.CollectionFormat.valueOf("{{{.}}}".toUpperCase(Locale.ROOT)){{/collectionFormat}}{{^collectionFormat}}null{{/collectionFormat}}, "{{baseName}}", {{paramName}}));{{^-last}}
-        {{/-last}}{{/queryParams}}{{/hasQueryParams}}{{#hasHeaderParams}}
+{{#queryParams}}{{#isExplode}}{{#hasVars}}{{#vars}}        localVarQueryParams.putAll(apiClient.parameterToMultiValueMap({{#collectionFormat}}ApiClient.CollectionFormat.valueOf("{{{.}}}".toUpperCase(Locale.ROOT)){{/collectionFormat}}{{^collectionFormat}}null{{/collectionFormat}}, "{{baseName}}", {{paramName}}.{{getter}}()));
+{{/vars}}{{/hasVars}}{{^hasVars}}        localVarQueryParams.putAll(apiClient.parameterToMultiValueMap({{#collectionFormat}}ApiClient.CollectionFormat.valueOf("{{{.}}}".toUpperCase(Locale.ROOT)){{/collectionFormat}}{{^collectionFormat}}null{{/collectionFormat}}, "{{baseName}}", {{paramName}}));
+{{/hasVars}}{{/isExplode}}{{^isExplode}}        localVarQueryParams.putAll(apiClient.parameterToMultiValueMap({{#collectionFormat}}ApiClient.CollectionFormat.valueOf("{{{.}}}".toUpperCase(Locale.ROOT)){{/collectionFormat}}{{^collectionFormat}}null{{/collectionFormat}}, "{{baseName}}", {{paramName}}));
+{{/isExplode}}{{/queryParams}}{{/hasQueryParams}}{{#hasHeaderParams}}
 
         {{#headerParams}}if ({{paramName}} != null)
         localVarHeaderParams.add("{{baseName}}", apiClient.parameterToString({{paramName}}));{{^-last}}

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

@@ -33,6 +33,7 @@
 import io.swagger.v3.oas.models.responses.ApiResponse;
 import io.swagger.v3.parser.core.models.ParseOptions;
 import io.swagger.v3.parser.util.SchemaTypeUtil;
+import lombok.SneakyThrows;
 import org.openapitools.codegen.ClientOptInput;
 import org.openapitools.codegen.CodegenConstants;
 import org.openapitools.codegen.CodegenModel;
@@ -1874,6 +1875,50 @@ public void testForJavaNativeJsonSubtype() throws IOException {
         assertFileNotContains(Paths.get(outputPath + "/src/main/java/org/openapitools/client/model/Pet.java"), "@JsonSubTypes.Type(value = Lizard.class, name = \"Lizard\")");
     }
 
+    @Test
+    public void shouldProperlyExplodeRestTemplateQueryParameters_issue907() {
+
+        final Map<String, File> files = generateFromContract(
+                "src/test/resources/3_0/java/explode-query-parameter.yaml",
+                JavaClientCodegen.RESTTEMPLATE
+        );
+
+        JavaFileAssert.assertThat(files.get("DefaultApi.java"))
+                .printFileContent()
+                .assertMethod("searchWithHttpInfo")
+                .bodyContainsLines("localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, \"regular-param\", regularParam));")
+                .bodyContainsLines("localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, \"someString\", objectParam.getSomeString()));")
+                .bodyContainsLines("localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, \"someBoolean\", objectParam.getSomeBoolean()));")
+                .bodyContainsLines("localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, \"someInteger\", objectParam.getSomeInteger()));")
+        ;
+    }
+
+    private static Map<String, File> generateFromContract(final String pathToSpecification, final String library) {
+        return generateFromContract(pathToSpecification, library, new HashMap<>());
+    }
+
+    @SneakyThrows
+    private static Map<String, File> generateFromContract(
+            final String pathToSpecification,
+            final String library,
+            final Map<String, Object> properties
+    ) {
+        final File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName("java")
+                .setLibrary(library)
+                .setAdditionalProperties(properties)
+                .setInputSpec(pathToSpecification)
+                .setOutputDir(output.getAbsolutePath());
+
+        final ClientOptInput clientOptInput = configurator.toClientOptInput();
+        final DefaultGenerator generator = new DefaultGenerator();
+        return generator.opts(clientOptInput).generate().stream()
+                .collect(Collectors.toMap(File::getName, Function.identity()));
+    }
+
     @Test
     public void testForJavaApacheHttpClientJsonSubtype() throws IOException {
         File output = Files.createTempDirectory("test").toFile().getCanonicalFile();

modules/openapi-generator/src/test/resources/3_0/java/explode-query-parameter.yaml

@@ -0,0 +1,45 @@
+openapi: 3.0.3
+info:
+  title: Explode query params
+  description: "Explode query params"
+  version: "1.0.0"
+servers:
+  - url: http://localhost:8080
+paths:
+  /api/search:
+    get:
+      operationId: Search
+      parameters:
+        - name: regular-param
+          in: query
+          required: false
+          schema:
+            type: string
+        - name: object-param
+          in: query
+          required: true
+          schema:
+            type: object
+            properties:
+              someString:
+                type: string
+              someBoolean:
+                type: boolean
+              someInteger:
+                type: integer
+      responses:
+        '200':
+          description: Some description.
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/SomeReturnValue'
+components:
+  schemas:
+    SomeReturnValue:
+      type: object
+      required:
+        - someValue
+      properties:
+        someValue:
+          type: string

samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/api/PetApi.java

@@ -186,6 +186,7 @@ public ResponseEntity<List<Pet>> findPetsByStatusWithHttpInfo(List<String> statu
 
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(ApiClient.CollectionFormat.valueOf("csv".toUpperCase(Locale.ROOT)), "status", status));
 
+
         final String[] localVarAccepts = { 
             "application/xml", "application/json"
          };
@@ -240,6 +241,7 @@ public ResponseEntity<List<Pet>> findPetsByTagsWithHttpInfo(List<String> tags) t
 
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(ApiClient.CollectionFormat.valueOf("csv".toUpperCase(Locale.ROOT)), "tags", tags));
 
+
         final String[] localVarAccepts = { 
             "application/xml", "application/json"
          };

samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/api/UserApi.java

@@ -328,6 +328,7 @@ public ResponseEntity<String> loginUserWithHttpInfo(String username, String pass
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "username", username));
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "password", password));
 
+
         final String[] localVarAccepts = { 
             "application/xml", "application/json"
          };

samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/api/PetApi.java

@@ -186,6 +186,7 @@ public ResponseEntity<List<Pet>> findPetsByStatusWithHttpInfo(List<String> statu
 
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(ApiClient.CollectionFormat.valueOf("csv".toUpperCase(Locale.ROOT)), "status", status));
 
+
         final String[] localVarAccepts = { 
             "application/xml", "application/json"
          };
@@ -240,6 +241,7 @@ public ResponseEntity<List<Pet>> findPetsByTagsWithHttpInfo(List<String> tags) t
 
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(ApiClient.CollectionFormat.valueOf("csv".toUpperCase(Locale.ROOT)), "tags", tags));
 
+
         final String[] localVarAccepts = { 
             "application/xml", "application/json"
          };

samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/api/UserApi.java

@@ -328,6 +328,7 @@ public ResponseEntity<String> loginUserWithHttpInfo(String username, String pass
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "username", username));
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "password", password));
 
+
         final String[] localVarAccepts = { 
             "application/xml", "application/json"
          };

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

@@ -349,6 +349,7 @@ public ResponseEntity<Void> testBodyWithQueryParamsWithHttpInfo(String query, Us
 
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "query", query));
 
+
         final String[] localVarAccepts = {  };
         final List<MediaType> localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
         final String[] localVarContentTypes = { 
@@ -575,6 +576,7 @@ public ResponseEntity<Void> testEnumParametersWithHttpInfo(List<String> enumHead
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "enum_query_integer", enumQueryInteger));
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "enum_query_double", enumQueryDouble));
 
+
         if (enumHeaderStringArray != null)
         localVarHeaderParams.add("enum_header_string_array", apiClient.parameterToString(enumHeaderStringArray));
         if (enumHeaderString != null)
@@ -655,6 +657,7 @@ public ResponseEntity<Void> testGroupParametersWithHttpInfo(Integer requiredStri
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "string_group", stringGroup));
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "int64_group", int64Group));
 
+
         if (requiredBooleanGroup != null)
         localVarHeaderParams.add("required_boolean_group", apiClient.parameterToString(requiredBooleanGroup));
         if (booleanGroup != null)
@@ -839,6 +842,7 @@ public ResponseEntity<Void> testQueryParameterCollectionFormatWithHttpInfo(List<
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(ApiClient.CollectionFormat.valueOf("csv".toUpperCase(Locale.ROOT)), "url", url));
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(ApiClient.CollectionFormat.valueOf("multi".toUpperCase(Locale.ROOT)), "context", context));
 
+
         final String[] localVarAccepts = {  };
         final List<MediaType> localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
         final String[] localVarContentTypes = {  };

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

@@ -186,6 +186,7 @@ public ResponseEntity<List<Pet>> findPetsByStatusWithHttpInfo(List<String> statu
 
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(ApiClient.CollectionFormat.valueOf("csv".toUpperCase(Locale.ROOT)), "status", status));
 
+
         final String[] localVarAccepts = { 
             "application/xml", "application/json"
          };
@@ -240,6 +241,7 @@ public ResponseEntity<Set<Pet>> findPetsByTagsWithHttpInfo(Set<String> tags) thr
 
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(ApiClient.CollectionFormat.valueOf("csv".toUpperCase(Locale.ROOT)), "tags", tags));
 
+
         final String[] localVarAccepts = { 
             "application/xml", "application/json"
          };

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

@@ -322,6 +322,7 @@ public ResponseEntity<String> loginUserWithHttpInfo(String username, String pass
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "username", username));
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "password", password));
 
+
         final String[] localVarAccepts = { 
             "application/xml", "application/json"
          };

samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/api/FakeApi.java

@@ -349,6 +349,7 @@ public ResponseEntity<Void> testBodyWithQueryParamsWithHttpInfo(String query, Us
 
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "query", query));
 
+
         final String[] localVarAccepts = {  };
         final List<MediaType> localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
         final String[] localVarContentTypes = { 
@@ -575,6 +576,7 @@ public ResponseEntity<Void> testEnumParametersWithHttpInfo(List<String> enumHead
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "enum_query_integer", enumQueryInteger));
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "enum_query_double", enumQueryDouble));
 
+
         if (enumHeaderStringArray != null)
         localVarHeaderParams.add("enum_header_string_array", apiClient.parameterToString(enumHeaderStringArray));
         if (enumHeaderString != null)
@@ -655,6 +657,7 @@ public ResponseEntity<Void> testGroupParametersWithHttpInfo(Integer requiredStri
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "string_group", stringGroup));
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "int64_group", int64Group));
 
+
         if (requiredBooleanGroup != null)
         localVarHeaderParams.add("required_boolean_group", apiClient.parameterToString(requiredBooleanGroup));
         if (booleanGroup != null)
@@ -839,6 +842,7 @@ public ResponseEntity<Void> testQueryParameterCollectionFormatWithHttpInfo(List<
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(ApiClient.CollectionFormat.valueOf("csv".toUpperCase(Locale.ROOT)), "url", url));
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(ApiClient.CollectionFormat.valueOf("multi".toUpperCase(Locale.ROOT)), "context", context));
 
+
         final String[] localVarAccepts = {  };
         final List<MediaType> localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
         final String[] localVarContentTypes = {  };

samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/api/PetApi.java

@@ -186,6 +186,7 @@ public ResponseEntity<List<Pet>> findPetsByStatusWithHttpInfo(List<String> statu
 
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(ApiClient.CollectionFormat.valueOf("csv".toUpperCase(Locale.ROOT)), "status", status));
 
+
         final String[] localVarAccepts = { 
             "application/xml", "application/json"
          };
@@ -240,6 +241,7 @@ public ResponseEntity<Set<Pet>> findPetsByTagsWithHttpInfo(Set<String> tags) thr
 
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(ApiClient.CollectionFormat.valueOf("csv".toUpperCase(Locale.ROOT)), "tags", tags));
 
+
         final String[] localVarAccepts = { 
             "application/xml", "application/json"
          };

samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/api/UserApi.java

@@ -322,6 +322,7 @@ public ResponseEntity<String> loginUserWithHttpInfo(String username, String pass
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "username", username));
         localVarQueryParams.putAll(apiClient.parameterToMultiValueMap(null, "password", password));
 
+
         final String[] localVarAccepts = { 
             "application/xml", "application/json"
          };