Hello World to Direct Web Remoting

This is a simple article that how to hello world to DWR (Direct Web Remoting).

First, go http://directwebremoting.org/dwr/download.html download dwr.jar, for me I download 2.0.6 version in order it can be supported in Google Appengine. Put dwr.jar in WEB-INF/lib

Second, download commons-logging-1.1.1.jar, put this jar in WEB-INF/lib also.

Third, modify web.xml to add this content of

  <display-name>DWR Servlet</display-name>


Fourth, create dwr.xml and with the content of

    "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN"

    <create creator="new" javascript="DWRStuff">
      <param name="class" value="com.fyhao.secs.DWRStuff"/>

Then you have to create DWRStuff.java file with the content of

package com.fyhao.secs;

public class DWRStuff {

    public String shownum(int a) {
        return "" + (a * 3);

Create a JSP file, called ajax.jsp with the content of

<%@ page contentType="text/html; charset=utf-8" language="java" import="java.sql.*" errorPage="" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "
<html xmlns="
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
<script src=’dwr/interface/DWRStuff.js’></script>
<script src=’dwr/engine.js’></script>
<script type="text/javascript">
function update() {
    DWRStuff.shownum(5, function(data) {

<div id="num"></div>

Remember the DWRStuff.js shown in the script source there.

Now, you can try to see if it is success.

Author: fyhao

Jebsen & Jessen Comms Singapore INTI University College Bsc (Hon) of Computer Science, Coventry University

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