SpringBoot2.0集成WebSocket，实现后台向前端推送信息

文章整体参考博客《SpringBoot2.0集成WebSocket，实现后台向前端推送信息》
我的博客只写我个人的代码

一、依赖引入

<modelVersion>4.0.0modelVersion>
	<parent>
		<groupId>org.springframework.bootgroupId>
		<artifactId>spring-boot-starter-parentartifactId>
		<version>2.1.4.RELEASEversion>
		<relativePath/> 
	parent>
	<groupId>cn.linkpowergroupId>
	<artifactId>SpringbootWebSocketTestartifactId>
	<version>0.0.1-SNAPSHOTversion>
	<name>SpringbootWebSocketTestname>
	<description>test demodescription>

	<properties>
		<java.version>1.8java.version>
		<project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8project.reporting.outputEncoding>
	properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.bootgroupId>
			<artifactId>spring-boot-starterartifactId>
		dependency>

		<dependency>
			<groupId>org.springframework.bootgroupId>
			<artifactId>spring-boot-starter-webartifactId>
		dependency>
		
		<dependency>
		    <groupId>org.springframework.bootgroupId>
		    <artifactId>spring-boot-starter-thymeleafartifactId>          
		dependency>
		
		<dependency>
			<groupId>org.springframework.bootgroupId>
			<artifactId>spring-boot-starter-websocketartifactId>
		dependency>
		<dependency>
			<groupId>org.springframework.bootgroupId>
			<artifactId>spring-boot-devtoolsartifactId>
			<scope>runtimescope>
			<optional>trueoptional> 
		dependency>
	dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.bootgroupId>
				<artifactId>spring-boot-maven-pluginartifactId>
			plugin>
		plugins>
	build>

二、代码布局和配置

2.1、配置

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

/**
 * 配置websocket
 * @author 7651
 *
 */
@Configuration
public class WebSocketConfig {
	
	@Bean
	public ServerEndpointExporter serverEndpointExporter(){
		return new ServerEndpointExporter();
	}
}

2.2、controller

import java.io.IOException;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
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 cn.linkpower.api.WebSocketServer;

@Controller
public class Test {
	
	@RequestMapping("/resTest")
	@ResponseBody
	public String resTest(){
		return "66666";
	}
	
	@RequestMapping("/test")
	public String test(){
		System.out.println("********");
		return "test/one";
	}
	
	@RequestMapping("/testtwo")
	public String testtwo(){
		System.out.println("********");
		return "two";
	}
	
	@GetMapping("/socket/{cid}")
	public String socket(@PathVariable String cid,Model model){
		model.addAttribute("cid", cid);
		return "socket";
	}
	
	//用于触发服务器去推送消息至指定的界面上
	@ResponseBody
	@RequestMapping("/socket/push/{cid}")
	public String pushToWeb(@PathVariable String cid,String message) {  
		try {
			WebSocketServer.sendInfo(message,cid);
		} catch (IOException e) {
			e.printStackTrace();
			return cid+"#"+e.getMessage();
		}  
		return cid +" ~~~ ";
	} 
}

2.3、socket服务

import java.io.IOException;
import java.util.concurrent.CopyOnWriteArraySet;

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.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

@ServerEndpoint("/websocket/{sid}")
@Component
public class WebSocketServer {
	private static Logger log = LoggerFactory.getLogger(WebSocketServer.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MyWebSocket对象。
	private static CopyOnWriteArraySet<WebSocketServer> webSocketSet = new CopyOnWriteArraySet<WebSocketServer>();

	// 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;

	// 接收sid
	private String sid = "";
	/**
     * 连接建立成功调用的方法*/
    @OnOpen
    public void onOpen(Session session,@PathParam("sid") String sid) {
        this.session = session;
        webSocketSet.add(this);     //加入set中
        addOnlineCount();           //在线数加1
        log.info("有新窗口开始监听:"+sid+",当前在线人数为" + getOnlineCount());
        this.sid=sid;
        try {
        	 sendMessage("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() {
        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"+sid+"的信息:"+message);
        //群发消息
        for (WebSocketServer item : webSocketSet) {
            try {
                item.sendMessage(message);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

	/**
	 * 
	 * @param session
	 * @param error
	 */
    @OnError
    public void onError(Session session, Throwable error) {
        log.error("发生错误  错误信息为："+error.getMessage());
        //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("sid") String sid) throws IOException {
    	log.info("推送消息到窗口"+sid+"，推送内容:"+message);
        for (WebSocketServer 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(sid==null) {
            		item.sendMessage(message);
            	}else if(item.sid.equals(sid)){
            		item.sendMessage(message);
            	}
            } catch (IOException e) {
                continue;
            }
        }
    }

    public static synchronized int getOnlineCount() {
        return onlineCount;
    }

    public static synchronized void addOnlineCount() {
        WebSocketServer.onlineCount++;
    }

    public static synchronized void subOnlineCount() {
        WebSocketServer.onlineCount--;
    }
}

2.4、页面

<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>666666title>
head>
<body>
	传递来的数据值cid:
	<input type="text" th:value="${cid}" id="cid"  />
body>
<script type="text/javascript">
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  
        
       	var cid = document.getElementById("cid").value;
       	console.log("cid-->"+cid);
       	var reqUrl = "http://localhost/websocket/"+cid;
       	socket = new WebSocket(reqUrl .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();  
        //});  
}

script>
html>

三、测试

四、完整代码demo

我的github 项目地址