[BUG][JAVA][JAXRS-SPEC] Multiple javadoc @return tags generated

Description

Generator jaxrs-spec generates invalid javadoc: It generates multiple @return tags: one for each possible response of the operation call. However, this is invalid (javadoc complains), since only a single instance of @return tag is expected.

openapi-generator version

open-api-generator-maven-plugin 7.11.0

OpenAPI declaration file content or url

The issue is reproducible with any OpenAPI declaration file declaring at least 2 responses for an operation, e.g.

https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/modules/openapi-generator-gradle-plugin/samples/local-spec/petstore-v3.0.yaml

generates multiple @return tags for any method in PetsApi.java

Generation Details

Use the following spec in pom.xml

    <build>
        <plugins>
            <plugin>
                <groupId>org.openapitools</groupId>
                <artifactId>openapi-generator-maven-plugin</artifactId>
                <version>7.11.0</version>
                <executions>
                    <execution>
                        <id>multipleResponses</id>
                        <phase>generate-sources</phase>
                        <goals>
                            <goal>generate</goal>
                        </goals>
                        <configuration>
                            <inputSpec>https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/modules/openapi-generator-gradle-plugin/samples/local-spec/petstore-v3.0.yaml</inputSpec>
                            <output>${project.build.directory}/generated-sources/cxf-rest/multiple-responses</output>
                            <generatorName>jaxrs-spec</generatorName>
                            <configOptions>
                                <apiPackage>com.multipleresponses.service</apiPackage>
                                <modelPackage>com.multipleresponses.data</modelPackage>
                                <sourceFolder>.</sourceFolder>
                                <useSwaggerAnnotations>false</useSwaggerAnnotations>
                                <generatePom>false</generatePom>
                                <interfaceOnly>true</interfaceOnly>
                                <useBeanValidation>true</useBeanValidation>
                                <useTags>true</useTags>
                                <dateLibrary>java8</dateLibrary>
                                <openApiSpecFileLocation />
                                <legacyDiscriminatorBehavior>false</legacyDiscriminatorBehavior>
                                <useJakartaEe>true</useJakartaEe>
                            </configOptions>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

Steps to reproduce

Run mvn generate-sources

Related issues/PRs

Suggest a fix

Multiple responses should be covered by a single @return tag (e.g. as a list).

Reproduce the issue with the Maven configuration and sample OpenAPI document, then inspect the generated PetsApi.java output after mvn generate-sources. Locate the jaxrs-spec generator template or entry point responsible for operation Javadocs and verify that generation produces one @return tag per method while preserving the response information and valid Javadoc.