有关dwr推送的笔记

想做一个web推送相关的东东，昨天搞了一天，终于把这些杂乱的配制弄清了，今天写出来方便以后记住，也方便大家看一下吧

1：引入dwr包，我用的是maven

<dependency>
    <groupId>org.directwebremoting</groupId>
    <artifactId>dwr</artifactId>
    <version>3.0.M1</version>
</dependency>

2：配制web.xml

我是在springMVC下进行的

<?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_2_5.xsd"
    version="2.5">
    <display-name>SmallSP Web Application</display-name>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <listener>
        <listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>
    </listener>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>

    <servlet>
        <servlet-name>springMVC</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath*:mvc/springMVC.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springMVC</servlet-name>
       <url-pattern>/dwr/*</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>springMVC</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
    
    
    <servlet-mapping>
       <servlet-name>default</servlet-name>
       <url-pattern>*.js</url-pattern>
    </servlet-mapping>
    
    <filter>
        <filter-name>Set Encoding</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>utf8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>Set Encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

以上代码中添加的是以下这一段

<servlet-mapping>
        <servlet-name>springMVC</servlet-name>
       <url-pattern>/dwr/*</url-pattern>
    </servlet-mapping>
<servlet-mapping>

3：配制springMVC.xml

在原有springMVC配制中添加以下

    <dwr:configuration /> 
    <dwr:annotation-config id="dwr" />
    <!-- 要求DWR将util.js和engine.js映射到dwrController -->
    <dwr:url-mapping />
    <!-- 定义dwr -->
    <dwr:controller id="dwrController" debug="true">
        <dwr:config-param name="allowScriptTagRemoting" value="true" />
        <dwr:config-param name="crossDomainSessionSecurity" value="false" />
        <dwr:config-param name="pollAndCometEnabled " value="true"/>
        <dwr:config-param name="activeReverseAjaxEnabled" value="true"/>
        <dwr:config-param name="debug " value="true"/>
    </dwr:controller>

4：配制 RemoteProxy

@Controller
@RemoteProxy(name = "directController") 
public class MyDwrController {
    
  @RemoteMethod 
  public String ShowHello(){
      return "hello";
  }
  
  @RemoteMethod
  public void send(HttpServletRequest request,String msg){   

        ServletContext sc = request.getSession().getServletContext();   
        ServerContext sctx = ServerContextFactory.get(sc);   
       
        //获得当前浏览 index.jsp 页面的所有脚本session   
        Collection<ScriptSession> sessions = sctx.getScriptSessionsByPage("/show");
        
        Util util = new Util(sessions);
        

        
        ScriptBuffer sb = new ScriptBuffer();  
        sb.appendScript("show(");  
        sb.appendData(msg);  
        sb.appendScript(")");  
          
        //推送  
        util.addScript(sb);  
        
        //util.addFunctionCall("show", ": " + msg);            
        //dwrtest为javascript函数     
        } 
}

5：发送页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> 
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>123</title>
<script type='text/javascript' src='/static/jquery-min.js'></script>  
<script type='text/javascript' src='<c:url value="/dwr/engine.js"/>'></script>  
<script type='text/javascript' src='<c:url value="/dwr/util.js" />'></script>  
<script type='text/javascript'  
    src='<c:url value="/dwr/interface/directController.js" />'></script>  
<script type="text/javascript">  
    function view() {  
        directController.ShowHello(function(data) {  
            alert(data);  
        });  
    } 
    
    function send(){
        dwr.engine.setActiveReverseAjax(true);  
        directController.send($("#msg").val()); 
    }
    
   
</script>  
</head>
<body>
     
      <input type="text" id="msg"  />  
     <input type="button" value="发送" id="but" onclick="send();" />  
    
</body>
</html>

6：接收页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>     
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type='text/javascript' src='/static/jquery-min.js'></script>  
<script type='text/javascript' src='<c:url value="/dwr/engine.js"/>'></script>  
<script type='text/javascript' src='<c:url value="/dwr/util.js" />'></script>  
<%-- <script type='text/javascript'  
    src='<c:url value="/dwr/interface/directController.js" />'></script>  --%>
    
<script type="text/javascript">  
    $(function(){  
        //这句话千万不能少 ，表示允许使用推送技术  
        dwr.engine.setActiveReverseAjax(true);  
    });  
    //这个函数是提供给后台推送的时候  调用的    
    function show(msg){  
        $("#message").text(msg);  
    }  
</script>
 
</head>
<body>
<div id="message" style=" 200px;height: 200px;border: 1px solid red ; text-align: center; padding: 5px;"></div> 
</body>
</html>

总结：就是以上步骤了。