Empty answer when trying to get JSON from Jersey Server-webservice

Empty answer when trying to get JSON from Jersey Server

try to build a RESTfull webservice.
On the backend I use a Jersey Server. On the Frontend I want to get the data with jQuery using ajax methods.
I took the example from http:-//www.mkyong.-com/webservices/jax-rs/json-example-with-jersey-jackson/ and tried to get the Data with $.getJSON and $.GET.

The problem is, that I always can't access the response data. Also jQuery always only executes the fail method.
After that I tried it with a simple servlet. With that I get the same result.

Does somebody know what I am doing wrong or how I can make this stuff working?

The project is deployed on a Tomcat 7.

<!DOCTYPE html>
<html>
<head>
    <script src="assets/js/jquery-2.0.2.js"></script></head>
<body>
<div id="first" class="container"></div>
<script type="text/javascript">
    var url = "http://127.0.0.1:8080/RESTfulExample/rest/json/metallica/get";
    $.get(url, function(data){
        alert("success");
        $("#first").empty().append(JSON.stringify(data))
    })
            .fail(function(){alert("fail");})
    ;
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
    <script src="assets/js/jquery-2.0.2.js"></script></head>
<body>
<div id="first" class="container"></div>
<script type="text/javascript">
    var url = "http://127.0.0.1:8080/RESTfulExample/rest/json/metallica/get";
    $.get(url, function(data){
        alert("success");
        $("#first").empty().append(JSON.stringify(data))
    })
            .fail(function(){alert("fail");})
    ;
</script>
</body>
</html>

Servlet:

JSONServlet.java
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package de.liebich.test.servlet.json;

import java.io.*;

import javax.servlet.*;
import javax.servlet.http.*;

import org.json.JSONArray;

public class JSONServlet extends HttpServlet {
    private static final long serialVersionUID = -462470710392739675L;

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        JSONArray arrayObj = new JSONArray();
        arrayObj.put("MCA");
        arrayObj.put("Amit Kumar");
        arrayObj.put("19-12-1986");
        arrayObj.put(24);
        arrayObj.put("Scored");
        arrayObj.put(new Double(66.67));


        response.setContentType("application/json");
        PrintWriter out = response.getWriter();
        out.println(arrayObj);
        out.close();
    }
}
package de.liebich.test.servlet.json;

import java.io.*;

import javax.servlet.*;
import javax.servlet.http.*;

import org.json.JSONArray;

public class JSONServlet extends HttpServlet {
private static final long serialVersionUID = -462470710392739675L;

public void doGet(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
  JSONArray arrayObj = new JSONArray();
  arrayObj.put("MCA");
  arrayObj.put("Amit Kumar");
  arrayObj.put("19-12-1986");
  arrayObj.put(24);
  arrayObj.put("Scored");
  arrayObj.put(new Double(66.67));


  response.setContentType("application/json");
  PrintWriter out = response.getWriter();
  out.println(arrayObj);
  out.close();
}
}

web.xml
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<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    id="WebApp_ID" version="3.0">
    <display-name>Test</display-name>
    <servlet>
      <servlet-name>JSONServlet</servlet-name>
      <servlet-class>de.liebich.test.servlet.json.JSONServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>JSONServlet</servlet-name>
        <url-pattern>/JSONServlet</url-pattern>
   </servlet-mapping>
</web-app>
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
id="WebApp_ID" version="3.0">
<display-name>Test</display-name>
<servlet>
      <servlet-name>JSONServlet</servlet-name>
      <servlet-class>de.liebich.test.servlet.json.JSONServlet</servlet-class>
    </servlet>
<servlet-mapping>
        <servlet-name>JSONServlet</servlet-name>
        <url-pattern>/JSONServlet</url-pattern>
   </servlet-mapping>
</web-app>

Jersey

Track.java
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package com.mkyong;

public class Track {

    String title;
    String singer;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getSinger() {
        return singer;
    }

    public void setSinger(String singer) {
        this.singer = singer;
    }

    @Override
    public String toString() {
        return "Track [title=" + title + ", singer=" + singer + "]";
    }

}
package com.mkyong;

public class Track {

String title;
String singer;

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}

public String getSinger() {
return singer;
}

public void setSinger(String singer) {
this.singer = singer;
}

@Override
public String toString() {
return "Track [title=" + title + ", singer=" + singer + "]";
}

}

JSONService
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package com.mkyong.rest;

import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;

import com.mkyong.Track;

@Path("/json/metallica")
public class JSONService {

    @GET
    @Path("/get")
    @Produces(MediaType.APPLICATION_JSON)
    public Track getTrackInJSON() {

        Track track = new Track();
        track.setTitle("Enter Sandman");
        track.setSinger("Metallica");

        return track;

    }

    @POST
    @Path("/post")
    @Consumes(MediaType.APPLICATION_JSON)
    public Response createTrackInJSON(Track track) {

        String result = "Track saved : " + track;
        return Response.status(201).entity(result).build();

    }

}
package com.mkyong.rest;

import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;

import com.mkyong.Track;

@Path("/json/metallica")
public class JSONService {

@GET
@Path("/get")
@Produces(MediaType.APPLICATION_JSON)
public Track getTrackInJSON() {

  Track track = new Track();
  track.setTitle("Enter Sandman");
  track.setSinger("Metallica");

return track;

}

@POST
@Path("/post")
@Consumes(MediaType.APPLICATION_JSON)
public Response createTrackInJSON(Track track) {

  String result = "Track saved : " + track;
  return Response.status(201).entity(result).build();

}

}

web.xml
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<web-app id="WebApp_ID" version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
    <display-name>Restful Web Application</display-name>

    <servlet>
        <servlet-name>jersey-serlvet</servlet-name>
        <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
        <init-param>
            <param-name>com.sun.jersey.config.property.packages</param-name>
            <param-value>com.mkyong.rest</param-value>
        </init-param>
        <init-param>
            <param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name>
            <param-value>true</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>jersey-serlvet</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>

</web-app>

I recently had to consume a REST API with a cross-domain call and i��ve found a solution in this excellent blog post from Kdecherf.

The problem with this implementation is that you need to call a method for each of your api��s methods.

So with the ContainerResponseFilter interface, you could do this for ALL of your methods �� transparently.
1 �C Configure web.xml

You just have to add an init-param to your Jersey Servlet
<init-param>
    <param-name>com.sun.jersey.spi.container.ContainerResponseFilters</param-name>
    <param-value>com.ezakus.api.web.security.ResponseCorsFilter</param-value>
</init-param>
2 �C ResponseCorsFilter
package com.ezakus.api.web.security;

import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.ResponseBuilder;

import com.sun.jersey.spi.container.ContainerRequest;
import com.sun.jersey.spi.container.ContainerResponse;
import com.sun.jersey.spi.container.ContainerResponseFilter;

public class ResponseCorsFilter implements ContainerResponseFilter {

    @Override
    public ContainerResponse filter(ContainerRequest req, ContainerResponse contResp) {

        ResponseBuilder resp = Response.fromResponse(contResp.getResponse());
        resp.header("Access-Control-Allow-Origin", "*")
                .header("Access-Control-Allow-Methods", "GET, POST, OPTIONS");

        String reqHead = req.getHeaderValue("Access-Control-Request-Headers");

        if(null != reqHead && !reqHead.equals("")){
            resp.header("Access-Control-Allow-Headers", reqHead);
        }

        contResp.setResponse(resp.build());
            return contResp;
    }

}