1.需要Tomcat7.0所以服务器
2.需要JDK7.0
3.手工加入Tomcat7.0中lib目录下的一下三个包catalina.jar、tomcat-coyote.jar、websocket-api.jar
4.项目部署后，请将服务器中当前项目下的catalina.jar、tomcat-coyote.jar、websocket-api.jar三个包删除。
5.项目目录结构如下
Servlet代码
package com.yc.websockets;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
import org.apache.catalina.websocket.MessageInbound;
import org.apache.catalina.websocket.StreamInbound;
import org.apache.catalina.websocket.WebSocketServlet;
import org.apache.catalina.websocket.WsOutbound;
@SuppressWarnings({"deprecation","unused", "serial"})
public class WebSocketTest extends WebSocketServlet {
private static List<MyMessageInbound> userList = new ArrayList<MyMessageInbound>();
private HttpSession session;
@Override
protected StreamInbound createWebSocketInbound(String str, HttpServletRequest request) {
session=request.getSession();
return new MyMessageInbound();
}
private class MyMessageInbound extends MessageInbound {
WsOutbound myoutbound;
/**
* 当用户登录时，WebSocket握手完成，创建完毕，WsOutbound用于向客户端发送数据
*/
public void onOpen(WsOutbound outbound) {
try {
System.out.println("Open Client.");
this.myoutbound = outbound;
userList.add(this); //添加当前用户
//向客服端发送信息
outbound.writeTextMessage(CharBuffer.wrap("Hello!"));
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 用户退出时，WebSocket关闭事件，参数status应该来自org.apache.catalina.websocket.Constants
* 中定义的几个常量，可以参考文档或者核对一下Tomcat的源码
*/
@Override
public void onClose(int status) {
userList.remove(this); //移除当前用户
}
/**
* 接受用户发过来的信息，有文本消息数据到达
*/
@Override
public void onTextMessage(CharBuffer cb) throws IOException {
for (MyMessageInbound mmib:userList){ //循环向所有在线用户发送当前用户的信息
CharBuffer buffer = CharBuffer.wrap(cb);
mmib.myoutbound.writeTextMessage(buffer); //调用指定用户的发送方法发送当前用户信息
mmib.myoutbound.flush(); //清空缓存
}
}
/**
* 有二进制消息数据到达，暂时没研究出这个函数什么情况下触发，js的WebSocket按理说应该只能send文本信息才对
*/
@Override
public void onBinaryMessage(ByteBuffer bb) throws IOException {
}
}
}
web.xml配置文件
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee;
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<display-name></display-name>
<servlet>
<servlet-name>webServlet</servlet-name>
<servlet-class>com.yc.websockets.WebSocketTest</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>webServlet</servlet-name>
<url-pattern>/webServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
</web-app>
index.html
<!DOCTYPE html>
<html>
<head>
<meta charset=UTF-8>
<title>Tomcat WebSocket Chat</title>
<script>
//设定WebSocket,注意协议是ws，请求是指向对应的WebSocketServlet的
/*设定WebSocket,注意协议是ws，请求是指向对应的WebSocketServlet的
var url = "ws://127.0.0.1:8080/j2ee6/echo.ws";
// 创建WebSocket实例，下面那个MozWebSocket是Firefox的实现
if (‘WebSocket‘ in window) {
ws = new WebSocket(url);
} else if (‘MozWebSocket‘ in window) {
ws = new MozWebSocket(url);
} else {
alert(‘Unsupported.‘);
return;
}*/
var ws = new WebSocket("ws://218.196.14.208:8080/webSocket/webServlet");
//WebSocket握手完成，连接成功的回调
//有个疑问，按理说new WebSocket的时候就会开始连接了，如果在设置onopen以前连接成功，是否还会触发这个回调
ws.onopen = function() {
//请求成功
};
//收到服务器发送的文本消息, event.data表示文本内容
ws.onmessage = function(message) {
document.getElementById("talkInfo").innerHTML+=message.data+"<hr style=‘border: 1px dashed #CCC‘/>";
};
//关闭WebSocket的回调
ws.onclose = function() {
//alert(‘Closed!‘);
};
// 通过WebSocket想向服务器发送一个文本信息
function postToServer() {
ws.send(document.getElementById("content").value);
document.getElementById("content").value = "";
}
//关闭WebSocket
function closeConnect() {
ws.close();
}
</script>
<style>
* {
margin: 0 auto;
padding: 0px;
font-size: 12px;
font-family: "微软雅黑";
line-height: 26px;
}
#bigbox {
margin:0px auto;
padding:0px;
width:70%;
}
#talkInfo{
width:100%;
height:500px;
border:1px solid red;
overflow: scorll;
}
#operation{
width:100%;
height:30px;
margin-top:10px;
}
#content{
height:30px;
line-height:30px;
}
</style>
</head>
<body>
<div id="bigbox">
<div id="talkInfo"></div>
<div id="operation">
<center>
<input type="text" name="content" id="content" size="100"/>
<input type="button" value=" 发送 " onclick="postToServer()" />
<input type="button" value=" 我闪 " onclick="closeConnect()" />
</center>
</div>
</div>
</body>
</html>