一、入门简介
正常聊天程序需要使用消息组件ActiveMQ或者Kafka等，这里是一个Websocket入门程序。
有人有疑问这个技术有什么作用，为什么要有它？
其实我们虽然有http协议，但是它有一个缺陷就是不能主动向客户端发送消息，而我们的基于Tcp协议的Websocket能够做到，所以这在多台机器之间通信提供了大大的方便。
二、入门案例
本案例使用Springboot+WebSocket+Thymeleaf
1.1pom.xml
<!-- websocket -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>
<!-- StringUtils -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
</dependency>
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1.2WebSocketConfig
package cn.xdl.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;
/**
* 开启WebSocket支持
* @author liurui
*
*/
@Configuration
public class WebSocketConfig {
@Bean
public ServerEndpointExporter serverEndpointExporter() {
return new ServerEndpointExporter();
}
}
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1.3CheckCenterController连接测试
package cn.xdl.controller;
import java.io.IOException;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
import cn.xdl.utils.result.AllResult;
/**
* 调用WebSocketServer
* @author liurui
*
*/
@Controller
@RequestMapping("/checkcenter")
public class CheckCenterController {
//页面请求
@GetMapping("/socket/{cid}")
public ModelAndView socket(@PathVariable String cid) {
ModelAndView mav=new ModelAndView("/socket");
mav.addObject("cid", cid);
return mav;
}
//推送数据接口
@ResponseBody
@RequestMapping("/socket/push/{cid}")
public AllResult pushToWeb(@PathVariable String cid,String message) {
try {
WebSocketServer.sendInfo(message,cid);
} catch (IOException e) {
e.printStackTrace();
return AllResult.build(500,cid+"#"+e.getMessage());
}
return AllResult.ok(cid);
}
}
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1.4测试socket.html
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>websocket</title>
<script type="text/javascript" src="http://nim.prec-robot.com/jzrobot/liurui/js/jquery.js"></script>
</head>
<body>
<h3>websocket测试页面</h3>
<input type="hidden" name="cid" th:value="${cid}" id="cid">
<input type="button" value="测试" onclick="push()">
<script>
var cid = $("#cid").val();
console.info("cid===="+cid);
var socket;
if(typeof(WebSocket) == "undefined") {
console.log("您的浏览器不支持WebSocket");
}else{
console.log("您的浏览器支持WebSocket");
//实现化WebSocket对象，指定要连接的服务器地址与端口 建立连接
//等同于socket = new WebSocket("ws://localhost:8083/checkcentersys/websocket/20");
socket = new WebSocket(("http://localhost:8888/hello-boot/websocket/"+cid).replace("http","ws"));
//打开事件
socket.onopen = function() {
console.log("Socket 已打开");
//socket.send("这是来自客户端的消息" + location.href + new Date());
};
//获得消息事件
socket.onmessage = function(msg) {
console.log(msg.data);
//发现消息进入 开始处理前端触发逻辑
};
//关闭事件
socket.onclose = function() {
console.log("Socket已关闭");
};
//发生了错误事件
socket.onerror = function() {
alert("Socket发生了错误");
//此时可以尝试刷新页面
}
//离开页面时，关闭socket
//jquery1.8中已经被废弃，3.0中已经移除
// $(window).unload(function(){
// socket.close();
//});
}
function push(){
var socket = new WebSocket(("http://localhost:8888/hello-boot/websocket/push/"+cid).replace("http","ws"));
}
</script>
</body>
</html>
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1.5聊天ImController
package cn.xdl.controller;
import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import cn.xdl.utils.result.AllResult;
import lombok.extern.slf4j.Slf4j;
/**
* websocket通信
* @author liurui
*
*/
@ServerEndpoint("/im/{userId}")
@Component
@Slf4j
public class ImController {
//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;
//旧：concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象。
//private static CopyOnWriteArraySet<ImController> webSocketSet = new CopyOnWriteArraySet<ImController>();
//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
private Session session;
//新：使用map对象，便于根据userId来获取对应的WebSocket
private static ConcurrentHashMap<String,ImController> websocketList = new ConcurrentHashMap<>();
//接收sid
private String userId="";
/**
* 连接建立成功调用的方法*/
@OnOpen
public void onOpen(Session session,@PathParam("userId") String userId) {
this.session = session;
websocketList.put(userId,this);
log.info("websocketList->"+JSON.toJSONString(websocketList));
//webSocketSet.add(this); //加入set中
addOnlineCount(); //在线数加1
log.info("有新窗口开始监听:"+userId+",当前在线人数为" + getOnlineCount());
this.userId=userId;
try {
sendMessage(JSON.toJSONString(AllResult.ok("连接成功")));
} catch (IOException e) {
log.error("websocket IO异常");
}
}
/**
* 连接关闭调用的方法
*/
@OnClose
public void onClose() {
if(websocketList.get(this.userId)!=null){
websocketList.remove(this.userId);
//webSocketSet.remove(this); //从set中删除
subOnlineCount(); //在线数减1
log.info("有一连接关闭！当前在线人数为" + getOnlineCount());
}
}
/**
* 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*/
@OnMessage
public void onMessage(String message, Session session) {
log.info("收到来自窗口"+userId+"的信息:"+message);
if(StringUtils.isNotBlank(message)){
JSONArray list=JSONArray.parseArray(message);
for (int i = 0; i < list.size(); i++) {
try {
//解析发送的报文
JSONObject object = list.getJSONObject(i);
String toUserId=object.getString("toUserId");
String contentText=object.getString("contentText");
object.put("fromUserId",this.userId);
//传送给对应用户的websocket
if(StringUtils.isNotBlank(toUserId)&&StringUtils.isNotBlank(contentText)){
ImController socketx=websocketList.get(toUserId);
//需要进行转换，userId
if(socketx!=null){
log.debug("服务端发送给客户端信息--object:{}",object);
socketx.sendMessage(JSON.toJSONString(AllResult.ok(object)));
//此处可以放置相关业务代码，例如存储到数据库
}
}
}catch (Exception e){
e.printStackTrace();
}
}
}
}
/**
*
* @param session
* @param error
*/
@OnError
public void onError(Session session, Throwable error) {
log.error("发生错误");
error.printStackTrace();
}
/**
* 实现服务器主动推送
*/
public void sendMessage(String message) throws IOException {
this.session.getBasicRemote().sendText(message);
}
/**
* 群发自定义消息
* */
/*public static void sendInfo(String message,@PathParam("userId") String userId) throws IOException {
log.info("推送消息到窗口"+userId+"，推送内容:"+message);
for (ImController item : webSocketSet) {
try {
//这里可以设定只推送给这个sid的，为null则全部推送
if(userId==null) {
item.sendMessage(message);
}else if(item.userId.equals(userId)){
item.sendMessage(message);
}
} catch (IOException e) {
continue;
}
}
}*/
public static synchronized int getOnlineCount() {
return onlineCount;
}
public static synchronized void addOnlineCount() {
ImController.onlineCount++;
}
public static synchronized void subOnlineCount() {
ImController.onlineCount--;
}
}
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1.6聊天socket_im.html
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<style>
.chat_div{
500px;
height:500px;
border:1px solid red;
text-align:center;
}
.chat_send_div{
float:left;
196px;
height:498px;
border:1px solid blue;
}
.chat_receive_div{
float:right;
290px;
height:498px;
border:1px solid green;
}
</style>
<script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.js"></script>
<script>
var socket;
function openSocket() {
if(typeof(WebSocket) == "undefined") {
console.log("您的浏览器不支持WebSocket");
}else{
console.log("您的浏览器支持WebSocket");
//实现化WebSocket对象，指定要连接的服务器地址与端口 建立连接
//等同于socket = new WebSocket("ws://localhost:8888/xxxx/im/25");
//var socketUrl="${request.contextPath}/im/"+$("#userId").val();
var socketUrl="http://localhost:8888/hello-boot/im/"+$("#userId").val();
socketUrl=socketUrl.replace("https","ws").replace("http","ws");
console.log(socketUrl)
socket = new WebSocket(socketUrl);
//打开事件
socket.onopen = function() {
console.log("websocket已打开");
//socket.send("这是来自客户端的消息" + location.href + new Date());
};
//获得消息事件
socket.onmessage = function(msg) {
console.log(msg);
//发现消息进入 开始处理前端触发逻辑contentText
//$.parseJSON(msg);
var data = msg.data;
var result = $.parseJSON(data);
var str = '';
if(result.data=="连接成功"){
console.info("test----if----"+data);
str +='<h3 style="color:blue;">';
str +='server:'+result.data;
str +='</h3>';
$(".chat_receive_div").append(str);
}else{
console.info("test---else-----"+result.data.contentText);
str +='<h3 style="color:blue;">';
str +='server:'+result.data.contentText;
str +='</h3>';
$(".chat_receive_div").append(str);
}
};
//关闭事件
socket.onclose = function() {
console.log("websocket已关闭");
};
//发生了错误事件
socket.onerror = function() {
console.log("websocket发生了错误");
}
}
}
function sendMessage() {
if(typeof(WebSocket) == "undefined") {
console.log("您的浏览器不支持WebSocket");
}else {
var str = '';
console.log("您的浏览器支持WebSocket");
console.log('[{"toUserId":"'+$("#toUserId").val()+'","contentText":"'+$("#contentText").val()+'"}]');
socket.send('[{"toUserId":"'+$("#toUserId").val()+'","contentText":"'+$("#contentText").val()+'"}]');
str +='<h3 style="color:gold;">';
str +=$("#toUserId").val()+':'+$("#contentText").val();
str +='</h3>';
$(".chat_send_div").append(str);
}
}
</script>
<body>
<p>【userId】：<div><input id="userId" name="userId" type="text" value="25"></div>
<p>【toUserId】：<div><input id="toUserId" name="toUserId" type="text" value="26"></div>
<p>【toUserId】：<div><input id="contentText" name="contentText" type="text" value="嗷嗷嗷"></div>
<p>【操作】：<div><a onclick="openSocket()">开启socket</a></div>
<p>【操作】：<div><a onclick="sendMessage()">发送消息</a></div>
<div class="chat_div">
<div class="chat_send_div">
<h3>
发送消息
</h3>
</div>
<div class="chat_receive_div">
<h3>
接受消息
</h3>
</div>
</div>
</body>
</html>
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本程序实现SpringBoot基于websocket的网页聊天。
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