springboot整合websocket

网上有一些例子,但是关于类并不是很全,所以写了这篇;

目录结构:

2.引用

[code]<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<groupId>com.springredis</groupId>
<artifactId>websocket</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>websocket</name>
<description>Demo project for Spring Boot</description>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>

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

<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>

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

</project>

默认启动类:

[code]import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;

@SpringBootApplication
public class WebsocketApplication {

public static void main(String[] args) {
SpringApplication.run(WebsocketApplication.class, args);
}
}

配置:

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

@Configuration
public class WebSocketConfig {
@Bean
public ServerEndpointExporter serverEndpointExporter() {
return new ServerEndpointExporter();
}

}

需要注意的是如果采用tomcat启动,引用javee对应jar,则不需要添加配置;

[code]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.ServerEndpoint;

import org.springframework.stereotype.Component;
@ServerEndpoint(value = "/websocket")
@Component
public class WebSocketServer {
//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;

/**
* 连接建立成功调用的方法*/
@OnOpen
public void onOpen(Session session) {
this.session = session;
webSocketSet.add(this);     //加入set中
addOnlineCount();           //在线数加1
System.out.println("有新连接加入！当前在线人数为" + getOnlineCount());
try {
sendMessage("连接成功");
} catch (IOException e) {
System.out.println("websocket IO异常");
}
}
//	//连接打开时执行
//	@OnOpen
//	public void onOpen(@PathParam("user") String user, Session session) {
//		currentUser = user;
//		System.out.println("Connected ... " + session.getId());
//	}

/**
* 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
System.out.println("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) {
System.out.println("来自客户端的消息:" + 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) {
System.out.println("发生错误");
error.printStackTrace();
}

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) throws IOException {
System.out.println(message);
for (WebSocketServer item : webSocketSet) {
try {
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--;
}
}

上面是一个经典例子

关于页面,分为Controller和页面部分

Controller

[code]import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/")
public class IndexController {
@RequestMapping("/")
public String Index() {
return "forward:/index.html";
}
}

页面

[code]<!DOCTYPE HTML>
<html>
<head>
<title>My WebSocket</title>
</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
if('WebSocket' in window){
websocket = new WebSocket("ws://localhost:8080/websocket");
}
else{
alert('Not support websocket')
}

//连接发生错误的回调方法
websocket.onerror = function(){
setMessageInnerHTML("error");
};

//连接成功建立的回调方法
websocket.onopen = function(event){
setMessageInnerHTML("open");
}

//接收到消息的回调方法
websocket.onmessage = function(event){
setMessageInnerHTML(event.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>

访问链接http://localhost:8080/