How to deploy a JAX-RS application on a Java SE en

Question

I want to code a RESTful web service with JAX-RS, and I want publish it on localhost like http://localhost:[port]. I read the following in this answer:

The Java SE 7 (JSR 336) and the Java SE 8 (JSR 337) specifications don't incorporate the JAX-RS component. However, JAX-RS applications can be published in Java SE environments (using RuntimeDelegate) and JAX-RS implementations also may support publication via JAX-WS.

The RuntimeDelegate is mentioned. How can I use it? If there are good examples on how to achieve it task, please share them with me.

Answer 1

To deploy a JAX-RS application in a Java SE environment, you could use RuntimeDelegate and a HTTP server supported by your JAX-RS implementation. A servlet container is not required.

The JSR 339 states the following:

In a Java SE environment a configured instance of an endpoint class can be obtained using the createEndpoint method of RuntimeDelegate. The application supplies an instance of Application and the type of endpoint required. An implementation MAY support zero or more endpoint types of any desired type.

How the resulting endpoint class instance is used to publish the application is outside the scope of this specification.

Jersey, the JAX-RS reference implementation, supports a range of HTTP servers which you can use to deploy JAX-RS applications in Java SE.

For example, with Grizzly and RuntimeDelegate, you can have the following:

public class Example {

    public static void main(String[] args) {

        ResourceConfig resourceConfig = new ResourceConfig();
        resourceConfig.register(GreetingsResource.class);

        HttpHandler handler = RuntimeDelegate.getInstance()
                .createEndpoint(resourceConfig, HttpHandler.class);

        HttpServer server = HttpServer.createSimpleServer(null, 8080);
        server.getServerConfiguration().addHttpHandler(handler);

        try {
            server.start();
            System.out.println("Press any key to stop the server...");
            System.in.read();
        } catch (Exception e) {
            System.err.println(e);
        }
    }

    @Path("/greetings")
    public static class GreetingsResource {

        @GET
        @Produces(MediaType.TEXT_PLAIN)
        public String getGreeting(){
            return "Hello from the other side.";
        }
    }
}

The application will be available at http://localhost:8080/greetings.

The following dependencies are required for the example shown above:

<dependency>
    <groupId>org.glassfish.grizzly</groupId>
    <artifactId>grizzly-http-server</artifactId>
    <version>2.3.30</version>
</dependency>
<dependency>
    <groupId>org.glassfish.jersey.containers</groupId>
    <artifactId>jersey-container-grizzly2-http</artifactId>
    <version>2.25.1</version>
</dependency>

Other supported implementations include:

• JDK HTTP Server
• Simple Server
• Jetty HTTP Server
• Netty HTTP Server

Jersey documentation also describes other deployment alternatives for a Java SE environment without RuntimeDelegate.