How to configure swagger with Jetty 11 running with jakarta EE 9 namespace?

Question

I am very new to swagger world and getting confused about how to go around configuring openapi.yaml from my apis. I am doing a CODE FIRST approach where we document the existing APIs using swagger. Since my server is Jetty 11, it can not work with javax.servlet, javax.* and swagger.jersey2.jaxrs dependencies.

After following the guidelines from Swagger 2.X Integration and Configuration and following the configuration for hooking swagger with jetty from Swagger Setup for Embedded Jetty Server, I used the following approach -

package com.example.hfs;

import com.example.hfs.*
import jakarta.servlet.Servlet;
import jakarta.servlet.ServletContainerInitializer;
import org.eclipse.jetty.server.HttpConfiguration;
import org.eclipse.jetty.server.HttpConnectionFactory;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.ServerConnector;
import org.eclipse.jetty.server.handler.ContextHandler;
import org.eclipse.jetty.server.handler.ContextHandlerCollection;
import org.eclipse.jetty.servlet.ServletContextHandler;
import org.eclipse.jetty.servlet.ServletHolder;
import org.eclipse.jetty.util.thread.QueuedThreadPool;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

/**
 *
 */
public class HFS {
    static public Properties props;

    // Constants
    final static public String RESPONSE_CONTENT_TYPE_JSON = "application/json;charset=UTF-8";
    //final static public String RESPONSE_CONTENT_TYPE_TEXT = "text/html;charset=UTF-8";

    public static void main(String[] args) throws Exception {
        System.out.println("StartHFS");

        initProperties();

        // Create and configure a ThreadPool.
        QueuedThreadPool threadPool = new QueuedThreadPool();
        threadPool.setName("server");

        // Create a Server instance.
        Server server = new Server(threadPool);

        // HTTP configuration and connection factory.
        HttpConfiguration httpConfig = new HttpConfiguration();
        HttpConnectionFactory http11 = new HttpConnectionFactory(httpConfig);

        // Create a ServerConnector to accept connections from clients.
        ServerConnector connector = new ServerConnector(server, 1, 1, http11);
        connector.setPort(8080);
        connector.setHost("0.0.0.0");
        connector.setAcceptQueueSize(128);
        server.addConnector(connector);

        // Swagger Setup for Embedded Jetty Server
        ServletContextHandler servletContextHandler = new ServletContextHandler(ServletContextHandler.SESSIONS);
        servletContextHandler.setContextPath("/");
        server.setHandler(servletContextHandler);

        // Setup API resources
        ServletHolder apiServlet = servletContextHandler.addServlet(Servlet.class, "/api/*");
        apiServlet.setInitOrder(1);
        apiServlet.setInitParameter("com.sun.jersey.config.property.packages", "com.api.resources;io.swagger.jakarta.json;io.swagger.jakarta.listing");

        // Setup Swagger Servlet
        ServletHolder swaggerServlet = servletContextHandler.addServlet("DefaultJakartaConfig.class", "/swagger-core");
        swaggerServlet.setInitOrder(2);
        swaggerServlet.setInitParameter("api.version", "1.0.0");

        addHandlers(server);

        // Start the Server so it starts accepting connections from clients.
        server.start();
        server.join();

        System.out.println("StartHFS DONE");
    }

And my gradle contains following dependencies :

plugins {
    id 'java'
//    id 'io.swagger.core.v3.swagger-gradle-plugin' version '2.1.9'
}


dependencies {
    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.6.0'
    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine'
    compile 'org.eclipse.jetty:jetty-server:11.0.0'
    compile 'org.eclipse.jetty:jetty-util:11.0.0'
    compile group: 'org.json', name: 'json', version: '20201115'
    compile group: 'org.eclipse.jetty', name: 'jetty-servlet', version: '11.0.0'
    compile group: 'io.swagger.core.v3', name: 'swagger-core-jakarta', version: '2.1.9'
    implementation 'io.swagger.core.v3:swagger-jaxrs2-jakarta:2.1.9'
    implementation 'io.swagger.core.v3:swagger-jaxrs2-servlet-initializer-v2-jakarta:2.1.9'
    compile 'org.apache.commons:commons-lang3:3.7'
    compile 'io.swagger.core.v3:swagger-jaxrs2-jakarta:2.1.7'
    compile 'jakarta.ws.rs:jakarta.ws.rs-api:3.0.0'
    compile 'jakarta.servlet:jakarta.servlet-api:5.0.0'
}

//resolve {
//    outputFileName = 'HfsOpenAPI'
//    outputFormat = 'YAML'
//    classpath = sourceSets.main.runtimeClasspath
//    buildClasspath = classpath
//    resourcePackages = ['io.test']
//    outputDir = file('main/resources')
//}

Now even after adding metadata into my code, I am not seeing only 404 on HTTP://localhost:8080/api/openapi.yaml. What is the mistake I am doing?

Answer 1

I was able to solve the issue with proper configuration on build.gradle and servlet configured into Jetty 11 server. The detailed solution is blogged on here - Hooking up openapi with Jetty 11.