DWR for page Push Simple instance

Implementation function: Sendmsg.jsp sends a message to the background, the background pushes the message to the Showmsg.jsp page.

1, Web. XML configuration, add the following content in Web. xml:

<!--using DWR for page message push  --><servlet><display-name>dwr servlet</display-name>< Servlet-name>dwr-invoker</servlet-name><servlet-class>org.directwebremoting.servlet.dwrservlet </servlet-class><init-param><param-name>debug</param-name><param-value>true</ param-value></init-param><!--the way to use polling and comet--><init-param><param-name> pollandcometenabled</param-name><param-value>true</param-value></init-param>< Load-on-startup>1</load-on-startup></servlet><servlet-mapping><servlet-name> Dwr-invoker</servlet-name><url-pattern>/dwr/*</url-pattern></servlet-mapping>

2, Configuration Dwr.xml

<! DOCTYPE dwr public    "-//getahead limited//dtd Direct Web Remoting 3.0//en"    "HTTP://GETAHEAD.ORG/DWR/DWR30.DTD" ><dwr>  <allow>  <!--The JavaScript value here is the name of the third JS file referenced by the page--    <create creator= "new" javascript= "sendmsg" >      <param Name= "class" >iwco.dwrs.SendMsg</param>      </create>  </allow></dwr>

3. Java class Sendmsg.java

Package Iwco.dwrs;import Java.util.collection;import Org.directwebremoting.scriptbuffer;import Org.directwebremoting.scriptsession;import Org.directwebremoting.webcontext;import Org.directwebremoting.webcontextfactory;import Org.directwebremoting.proxy.dwr.util;public class SendMsg {@ Suppresswarnings ("deprecation") public void sendmsg (String msg) {//get context webcontext Contex = Webconte                    Xtfactory.get ();          Get the page you want to push to DWR3 for the project name, be sure to add it.                  collection<scriptsession> sessions = Contex.getscriptsessionsbypage ("/dwrtest/showmsg.jsp");                  Do not know how to explain this, Util Util = new Util (sessions);           The following is the creation of a JavaScript script, which is equivalent to adding a sentence show (msg) to the page script;          Scriptbuffer sb = new Scriptbuffer ();          Sb.appendscript ("Show (");          Sb.appenddata (msg);                    Sb.appendscript (")");      Push Util.addscript (SB); }  }

4. Page

sendmsg.jsp

<%@ page language= "java" import= "java.util.*" pageencoding= "UTF-8"%><%string path = Request.getcontextpath () ; String basepath = request.getscheme () + "://" +request.getservername () + ":" +request.getserverport () +path+ "/";%> <! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" >
showmsg.jsp
<%@ page language= "java" import= "java.util.*" pageencoding= "UTF-8"%><%string path = Request.getcontextpath () ; String basepath = request.getscheme () + "://" +request.getservername () + ":" +request.getserverport () +path+ "/";%> <! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" >

DWR for page Push Simple instance