JAVA JSON Restfull WebService No 'Access-Control-Allow-Origin' header is present on the requested resource <p>I have a JAVA RESTful webservice which will return JSON string and it was written in Java. My problem is when I send request to that webservice with below URL</p> <pre><code>http://localhost:8080/WebServiceXYZ/Users/insert </code></pre> <p>it's giving me the below error message</p> <pre><code>XMLHttpRequest cannot load http://localhost:8080/WebServiceXYZ/Users/insert/. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:8100' is therefore not allowed access. The response had HTTP status code 500. </code></pre> <p>Here is my Code</p> <pre><code>package com.lb.jersey; import javax.ws.rs.POST; import javax.ws.rs.Path; import javax.ws.rs.Produces; import javax.ws.rs.core.MediaType; import org.json.JSONException; import org.json.JSONObject; @Path("/Users") public class RegistrationService { @POST @Produces(MediaType.APPLICATION_JSON) @Path("/insert") public String InsertCredentials (String json) throws JSONException { java.util.Date dt = new java.util.Date(); java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String currentTime = sdf.format(dt); String phone = null; JSONObject returnJson = new JSONObject(); try { JSONObject obj = new JSONObject(json); JSONObject result1 = obj.getJSONObject("Credentials"); phone = result1.getString("phone"); DBConnection conn = new DBConnection(); int checkUserID = conn.GetUserIDByPhone(phone); if(checkUserID &lt;= 0) { DBConnection.InsertorUpdateUsers(phone, currentTime); } int userID = conn.GetUserIDByPhone(phone); int otp = (int) Math.round(Math.random()*1000); DBConnection.InsertorUpdateCredentials(userID, otp, currentTime); JSONObject createObj = new JSONObject(); createObj.put("phone", phone); createObj.put("otp", otp); createObj.put("reqDateTime", currentTime); returnJson.put("Credentials", createObj); System.out.println(returnJson); } catch (Exception e) { } return returnJson.toString(); } } </code></pre> <p>My web.xml code</p> <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt; &lt;web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5"&gt; &lt;display-name&gt;WebServiceXYZ&lt;/display-name&gt; &lt;servlet&gt; &lt;servlet-name&gt;Jersey REST Service&lt;/servlet-name&gt; &lt;servlet-class&gt;com.sun.jersey.server.impl.container.servlet.ServletAdaptor&lt;/servlet-class&gt; &lt;init-param&gt; &lt;param-name&gt;com.sun.jersey.config.property.packages&lt;/param-name&gt; &lt;param-value&gt;com.lb.jersey&lt;/param-value&gt; &lt;/init-param&gt; &lt;load-on-startup&gt;1&lt;/load-on-startup&gt; &lt;/servlet&gt; &lt;servlet-mapping&gt; &lt;servlet-name&gt;Jersey REST Service&lt;/servlet-name&gt; &lt;url-pattern&gt;/*&lt;/url-pattern&gt; &lt;/servlet-mapping&gt; &lt;/web-app&gt; </code></pre> <p>I already read many articles but no progress, so please let me know, How can I handle this issue?</p>