MediaType.APPLICATION_XML and MediaType.APPLICATION_JSON in a Jersey demo application

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JAX-RS has a bunch of built-in handlers that can marshal to and from a few different specific Java types.

Once we start dealing with custom data-binding (marshalling/unmarshalling to Java objects), we are in a different ball game. We now require some other MessageBodyWriters and MesageBodyReaders.

Fortunately, there are already readers and writers available for XML and JSON data-binding. JAX-RS comes with a standard XML marshalling/unmarshalling, with one caveat.. we must use JAXB annotations. So for your Test class, assuming it's like this

public class Test {
    private String name;
    private int age;

    public String getName() { return name; }
    public void setName(String name) { this.name = name;}
    public int getAge() { return age; }
    public void setAge(int age) { this.age = age; }  
}

to make allow the JAXB provider to unmarshall/marshall, we should provide, at minimum, an @XmlRootElement

@XmlRootElement
public class Test {
   ....
}

Doing this should allow the XML to work.

As far as the JSON, JSON binding is not a standard par of the specification, but we can simply add a dependency to the project, that will automatically register the needed provider to handle JSON binding. You can look at the pom.xml for the json-moxy example. You will see this needed dependency

<dependency>
    <groupId>org.glassfish.jersey.media</groupId>
    <artifactId>jersey-media-moxy</artifactId>
</dependency>

What the dependency allows application to do, is marshal/unmarshal jSON to/from our Java objects, using the JAXB annotations. So just by adding this dependency to the pom.xml. The application should work. Just tested.

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user2737950
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user2737950

Updated on November 02, 2020

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  • user2737950
    user2737950 over 3 years

    Once I got this Question Latest Jersey example does not work answered, I run into another curious problem:

    The server, GET methods work fine. I tested and added some test code for helloworld-pure-jax-rs example, and esp. added a POST request for JSON:

    package org.glassfish.jersey.examples.helloworld.jaxrs;
    
    import javax.ws.rs.Consumes;
    import javax.ws.rs.GET;
    import javax.ws.rs.POST;
    import javax.ws.rs.Path;
    import javax.ws.rs.PathParam;
    import javax.ws.rs.Produces;
    import javax.ws.rs.core.MediaType;
    import javax.ws.rs.core.Response;
    
    
    @Path("helloworld")
    public class HelloWorldResource
    {
        public static final String  CLICHED_MESSAGE = "Hello World!";
    
        @GET
        @Produces(MediaType.TEXT_PLAIN)
        public String getHello()
        {
            return CLICHED_MESSAGE;
        }
    
        @GET
        @Produces(MediaType.APPLICATION_JSON)
        public String getHelloJson()
        {
            return "{ \"message\":" + CLICHED_MESSAGE + "}";
        }
    
        @GET
        @Produces(MediaType.TEXT_HTML)
        public String getHelloHtml()
        {
            return "<html> " + "<title>" + "Hello Jersey" + "</title>" + "<body><h1>" + CLICHED_MESSAGE
                    + "</body></h1>" + "</html> ";
        }
    
        @GET
        @Produces(MediaType.TEXT_PLAIN)
        @Path("/v2")
        public String getHello2()
        {
            return CLICHED_MESSAGE + " v2";
        }
    
        @GET
        @Produces(MediaType.TEXT_PLAIN)
        @Path("/{id}")
        public String getHelloId(@PathParam("id") String id)
        {
            return CLICHED_MESSAGE + " Parameter: " + id;
        }
    
        @GET
        @Produces(MediaType.TEXT_PLAIN)
        @Path("/id/{id : [a-zA-Z][a-zA-Z_0-9]}")
        public String getHelloIdId(@PathParam("id") String id)
        {
            return CLICHED_MESSAGE + " Parameter: " + id;
        }
    
        @POST
        @Consumes(MediaType.TEXT_PLAIN)
        @Produces(MediaType.TEXT_PLAIN)
        public Response test(String test)
        {
            if (test.equals("test"))
                return Response.status(400).entity("Error: " + test).build();
            return Response.status(200).entity(test).build();
        }
    
        @POST
        @Path("/test")
        @Consumes(MediaType.APPLICATION_JSON)
        @Produces(MediaType.APPLICATION_JSON)
        public Response testJSON(Test test)
        {
            String result = "Test JSON created : " + test.getName() + "" + test.getAge();
            // return result;
            return Response.status(200).entity(result).build();
        }
    
        @POST
        @Path("/test")
        @Consumes(MediaType.APPLICATION_XML)
        @Produces(MediaType.APPLICATION_XML)
        public Response testXML(Test test)
        {
            String result = "Test XML created : " + test.getName() + "" + test.getAge();
            // return result;
            return Response.status(200).entity(result).build();
        }
    
    }
    

    Here ist the rest of the classes:

    package org.glassfish.jersey.examples.helloworld.jaxrs;
    
    import java.io.IOException;
    import java.net.InetSocketAddress;
    import java.net.URI;
    
    import javax.ws.rs.core.UriBuilder;
    import javax.ws.rs.ext.RuntimeDelegate;
    
    import com.sun.net.httpserver.HttpHandler;
    import com.sun.net.httpserver.HttpServer;
    
    /**
     * Hello world application using only the standard JAX-RS API and lightweight
     * HTTP server bundled in JDK.
     *
     * @author Martin Matula (martin.matula at oracle.com)
     */
    @SuppressWarnings("restriction")
    public class App
    {
    
        /**
         * Starts the lightweight HTTP server serving the JAX-RS application.
         *
         * @return new instance of the lightweight HTTP server
         * @throws IOException
         */
        static HttpServer startServer() throws IOException
        {
            // create a new server listening at port 8080
            HttpServer server = HttpServer.create(new InetSocketAddress(getBaseURI().getPort()), 0);
    
            // create a handler wrapping the JAX-RS application
            HttpHandler handler = RuntimeDelegate.getInstance().createEndpoint(new JaxRsApplication(),
                    HttpHandler.class);
    
            // map JAX-RS handler to the server root
            server.createContext(getBaseURI().getPath(), handler);
    
            // start the server
            server.start();
    
            return server;
        }
    
        public static void main(String[] args) throws IOException
        {
            System.out.println("\"Hello World\" Jersey Example Application");
    
            HttpServer server = startServer();
    
            System.out.println("Application started.\n" + "Try accessing " + getBaseURI()
                    + "helloworld in the browser.\n" + "Hit enter to stop the application...");
            System.in.read();
            server.stop(0);
        }
    
        private static int getPort(int defaultPort)
        {
            final String port = System.getProperty("jersey.config.test.container.port");
            if (null != port)
            {
                try
                {
                    return Integer.parseInt(port);
                }
                catch (NumberFormatException e)
                {
                    System.out.println("Value of jersey.config.test.container.port property"
                            + " is not a valid positive integer [" + port + "]."
                            + " Reverting to default [" + defaultPort + "].");
                }
            }
            return defaultPort;
        }
    
        /**
         * Gets base {@link URI}.
         *
         * @return base {@link URI}.
         */
        public static URI getBaseURI()
        {
            return UriBuilder.fromUri("http://localhost/").port(getPort(8080)).build();
        }
    }
    
    
    public class Test
    {
        public int      age     = 0;
        public String   name    = "";
    
        /**
         * 
         */
        public Test()
        {
            super();
        }
    
        /**
         * @param age
         */
        public Test(int age)
        {
            super();
            this.age = age;
        }
    
        /**
         * @param name
         */
        public Test(String name)
        {
            super();
            this.name = name;
        }
    
        /**
         * @param name
         * @param age
         */
        public Test(String name, int age)
        {
            super();
            this.name = name;
            this.age = age;
        }
    
        public int getAge()
        {
            return age;
        }
    
        public String getName()
        {
            return name;
        }
    
        public void setAge(int age)
        {
            this.age = age;
        }
    
        public void setName(String name)
        {
            this.name = name;
        }
    }
    
    package org.glassfish.jersey.examples.helloworld.jaxrs;
    
    import java.util.Collections;
    import java.util.HashSet;
    import java.util.Set;
    import javax.ws.rs.core.Application;
    
    public class JaxRsApplication extends Application
    {
        private final Set<Class<?>> classes;
    
        public JaxRsApplication()
        {
            HashSet<Class<?>> c = new HashSet<Class<?>>();
            c.add(HelloWorldResource.class);
            classes = Collections.unmodifiableSet(c);
        }
    
        @Override
        public Set<Class<?>> getClasses()
        {
            return classes;
        }
    }
    

    This works fine for the plain text post message, but fpr the json (MediaType.APPLICATION_JSON )and xml part (MediaType.APPLICATION_XML) it fails stating not a supported media type. Any idea what could be wrong?