基于Tomcat的WebSocket
- - ITeye博客之前大概的看过WebSocket,当时Tomcat还不支持WebSocket,所以当时写了一篇基于Jetty的WebSocket实现,地址如下:. 现在Tomcat7.0.27发布了,从这个版本开始Tomcat就支持WebSocket了. Tomcat的WebSocket和Jetty的大致上差不多,大同小异,这里就简单的贴两个类吧:.
之前大概的看过WebSocket,当时Tomcat还不支持WebSocket,所以当时写了一篇基于Jetty的WebSocket实现,地址如下:
http://redstarofsleep.iteye.com/blog/1307608
现在Tomcat7.0.27发布了,从这个版本开始Tomcat就支持WebSocket了。
Tomcat的WebSocket和Jetty的大致上差不多,大同小异,这里就简单的贴两个类吧:
第一个类,这个和Jetty一样,需要一个Servlet来处理WebSocket请求:
package lhc.websocket; import org.apache.catalina.websocket.StreamInbound; import org.apache.catalina.websocket.WebSocketServlet; public class MyWebSocketServlet extends WebSocketServlet { private static final long serialVersionUID = -7178893327801338294L; @Override protected StreamInbound createWebSocketInbound(String arg0) { System.out.println("##########"); return new MyMessageInbound(); } }
这个Servlet继承自WebSocketServlet,实现createWebSocketInbound方法。该方法返回第二个类的实例。
第二个类,处理每一次具体的WebSocket任务:
package lhc.websocket; import java.io.IOException; import java.nio.ByteBuffer; import java.nio.CharBuffer; import org.apache.catalina.websocket.MessageInbound; public class MyMessageInbound extends MessageInbound { @Override protected void onBinaryMessage(ByteBuffer arg0) throws IOException { // TODO Auto-generated method stub } @Override protected void onTextMessage(CharBuffer msg) throws IOException { System.out.println("~~~~~~~:" + msg); } }
这个类继承自MessageInbound类,必须实现onBinaryMessage和onTextMessage方法。Jetty中只有一个onMessage方法,而Tomcat细化成了2个方法。
最后,web.xml中进行一下Servlet的配置。
<?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" 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_3_0.xsd" id="WebApp_ID" version="3.0"> <display-name>wsoc</display-name> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> <servlet> <servlet-name>mywebsocket</servlet-name> <servlet-class>lhc.websocket.MyWebSocketServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>mywebsocket</servlet-name> <url-pattern>*.do</url-pattern> </servlet-mapping> </web-app>
页面的话,就是标准的HTML5的websocket,这个和服务器是否是Tomcat或者Jetty是无关的:
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Index</title> <script type="text/javascript"> var ws = null; function startWebSocket() { if ('WebSocket' in window) ws = new WebSocket("ws://localhost:8080/wsoc/mywebsocket.do"); else if ('MozWebSocket' in window) ws = new MozWebSocket("ws://localhost:8080/wsoc/mywebsocket.do"); else alert("not support"); ws.onmessage = function(evt) { alert(evt.data); }; ws.onclose = function(evt) { alert("close"); }; ws.onopen = function(evt) { alert("open"); }; } function sendMsg() { ws.send(document.getElementById('writeMsg').value); } </script> </head> <body onload="startWebSocket();"> <input type="text" id="writeMsg"></input> <input type="button" value="send" onclick="sendMsg()"></input> </body> </html>