1、首先引用以下包pom.xml
<dependency> <groupId>org.apache.tomcat</groupId> <artifactId>catalina</artifactId> <version>6.0.26</version> </dependency> <dependency> <groupId>javax.websocket</groupId> <artifactId>javax.websocket-api</artifactId> <version>1.0</version> </dependency> <dependency> <groupId>org.apache.tomcat</groupId> <artifactId>tomcat-coyote</artifactId> <version>9.0.0.M13</version> </dependency>
2、web.xml
<servlet> <servlet-name>wsChat</servlet-name> <servlet-class>com.r7.galaxy.websocket.servlet.MyWebSocket</servlet-class> </servlet> <servlet-mapping> <servlet-name>wsChat</servlet-name> <url-pattern>/websocket/chat</url-pattern> </servlet-mapping>
3、java代码
import java.io.IOException;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import com.test.core.WebSocketManager;
import com.test.User;
/***
* 该注解用来指定一个URI，客户端可以通过这个URI来连接到WebSocket。类似Servlet的注解mapping。无需在web.xml中配置。
* @author Wangcc
*
*/
@ServerEndpoint("/chat")
public class MyWebSocket {
Log log = LogFactory.getLog(MyWebSocket.class);
/**
* 连接建立成功调用的方法
* @param session 可选的参数。session为与某个客户端的连接会话，需要通过它来给客户端发送数据
*/
@OnOpen
public void onOpen(Session session){
WebSocketManager wsm = WebSocketManager.getInstance();
User mu = new User();
mu.setId("44");
wsm.registerWebSocket(mu, session);
}
/**
* 连接关闭调用的方法
*/
@OnClose
public void onClose(Session session){
WebSocketManager wsm = WebSocketManager.getInstance();
User mu = new User();
mu.setId("44");
wsm.unregisterWebSocket(mu, session);
}
/**
* 收到客户端消息后调用的方法
* @param message 客户端发送过来的消息
* @param session 可选的参数
*/
@OnMessage
public void onMessage(String message, Session session) {
WebSocketManager wsm = WebSocketManager.getInstance();
User mu = new User();
mu.setId("44");
try {
wsm.sendMessage(message, mu, null);
} catch (IOException e) {
log.error(" send message have error in webSocket "+e.getMessage());
}
}
/**
* 发生错误时调用
* @param session
* @param error
*/
@OnError
public void onError(Session session, Throwable error){
log.error("websocket have error");
}
}
package com.test.core;
import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArraySet;
import javax.websocket.Session;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import com.test.User;
/***
*
* @author charles.k
*
*/
public class WebSocketManager {
Log log = LogFactory.getLog(WebSocketManager.class);
// 静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。
private static int onlineCount = 0;
// concurrent包的线程安全Set，用来存放每个客户端对应的WebSocketSession对象。若要实现服务端与单一客户端通信的话，可以使用Map来存放，其中Key可以为用户标识
private static ConcurrentHashMap<String, CopyOnWriteArraySet<Session>> websocketMap = new ConcurrentHashMap<String, CopyOnWriteArraySet<Session>>();
private static WebSocketManager instance;
/***
* 单例
*
* @return
*/
public static WebSocketManager getInstance() {
if (instance == null) {
synchronized (WebSocketManager.class) {
if (instance == null)
instance = new WebSocketManager();
}
}
return instance;
}
/****
* 连接
* @param mu
* @param session
*/
public void registerWebSocket(User mu, Session session) {
CopyOnWriteArraySet<Session> set = websocketMap.get(mu.getId());
if(set==null||set.size()==0){
set = new CopyOnWriteArraySet<Session> ();
}
set.add(session);
websocketMap.put(mu.getId(), set);
setOnlineNumber();
}
/**
* 连接关闭
*/
public void unregisterWebSocket(User mu, Session session) {
CopyOnWriteArraySet<Session> set = websocketMap.get(mu.getId());
if(set!=null){
set.remove(session);
if(set.size()>0){
websocketMap.put(mu.getId(), set);
}
}
setOnlineNumber();
}
/**
* 收到客户端消息后调用的方法
*
* @param message 客户端发送过来的消息
* @param session 可选的参数
* @throws IOException
*/
public void sendMessage(String message, User mu ,Session session) throws IOException {
CopyOnWriteArraySet<Session> sessionSet = websocketMap.get(mu.getId());
// 群发消息
if(sessionSet!=null){
for (Session clientSession : sessionSet) {
clientSession.getBasicRemote().sendText(message);
}
}
if(session!=null){
session.getBasicRemote().sendText(message);
}
}
private void setOnlineNumber(){
onlineCount=websocketMap.size();
}
}
package com.test;
public class User {
private String id;
private String userAge;
private String userName;
private String userPassword;
public User(){
super();
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getUserPassword() {
return userPassword;
}
public void setUserPassword(String userPassword) {
this.userPassword = userPassword;
}
public String getUserAge() {
return userAge;
}
public void setUserAge(String userAge) {
this.userAge = userAge;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getUserPassward() {
return userPassword;
}
public void setUserPassward(String userPassward) {
this.userPassword = userPassward;
}
public User(String id, String userAge, String userName) {
super();
this.id = id;
this.userAge = userAge;
this.userName = userName;
}
}
4、html代码
<!DOCTYPE HTML> <html> <head> <base href="<%=basePath%>"> <title>My WebSocket</title> <script type="text/JavaScript"> </script> </head> <body> Welcome <br /> <input id="text" type="text" /> <button onclick="send()">Send</button> <button onclick="closeWebSocket()">Close</button> <div id="message"></div> </body> <script type="text/JavaScript"> var websocket = null; //判断当前浏览器是否支持WebSocket console.log(window); if ('WebSocket' in window) { websocket = new WebSocket("ws://localhost:8080/projectName/chat"); } else { alert('Not support websocket'); } //连接发生错误的回调方法 websocket.onerror = function(e) { e = e||event; setMessageInnerHTML(e.data); }; //连接成功建立的回调方法 websocket.onopen = function(e) { e = e||event; setMessageInnerHTML("open"); }; //接收到消息的回调方法 websocket.onmessage = function(e) { e = e||event; setMessageInnerHTML(e.data); }; //连接关闭的回调方法 websocket.onclose = function() { setMessageInnerHTML("close"); }; //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。 window.onbeforeunload = function() { websocket.close(); }; //将消息显示在网页上 function setMessageInnerHTML(innerHTML) { document.getElementById('message').innerHTML += innerHTML + '<br/>'; } //关闭连接 function closeWebSocket() { websocket.close(); } //发送消息 function send() { var message = document.getElementById('text').value; websocket.send(message); } </script> </html>
ok
注意要是tomcat启动出现问题，
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