springboot整合websocket

1.创建springboot项目，引入spring-boot-starter-websocket依赖

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

全部依赖如下：

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.7.10</version><relativePath/> <!-- lookup parent from repository --></parent><groupId>com.cherry</groupId><artifactId>demo</artifactId><version>0.0.1-SNAPSHOT</version><name>demo</name><description>Demo project for Spring Boot</description><properties><java.version>1.8</java.version></properties><dependencies>
<!--        // springboot整合websocket--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-websocket</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId><scope>runtime</scope><optional>true</optional></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></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><configuration><excludes><exclude><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></exclude></excludes></configuration></plugin></plugins></build></project>

2.创建一个TextWebSocketHandler的子类，重写handleTextMessage、afterConnectionEstablished、afterConnectionClosed方法

handleTextMessage()

handleTextMessage()方法通过英文方法名可知，用于处理文本信息。它有两个参数分别是：WebSocketSession和TextMessage。WebSocketSession可以通过sendMessage将消息发送给前台。TextMessage通过调用getPayload（）接收前台消息体。

afterConnectionEstablished()

afterConnectionEstablished方法通过英文方法名可知，用于连接确立之后。
通过WebSocketSession的sendMessage方法，将创建的TextMessage对象给前台。

afterConnectionClosed

afterConnectionClosed方法用于连接关闭之后。参数有WebSocketSession和CloseStatus。WebSocketSession的方法sendMessage可以向前台发送消息，CloseStatus的getReason方法获得关闭的原因。

package com.cherry.demo.handler;import org.springframework.stereotype.Component;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.TextWebSocketHandler;import java.io.IOException;@Component
public class MyHandler extends TextWebSocketHandler {// 客户端想服务器发消息@Overridepublic void handleTextMessage(WebSocketSession session, TextMessage message)throws IOException {// 接收客户端的消息  message.getPayload()消息体System.out.println("获取到消息 >> " + message.getPayload());session.sendMessage(new TextMessage("消息已收到"));// 向服务端发送消息if(message.getPayload().equals("10")){for (int i = 0; i < 10; i++) {session.sendMessage(new TextMessage("消息 -> " + i));try {Thread.sleep(100);} catch (InterruptedException e) {e.printStackTrace();}}}}// 建议连接时@Overridepublic void afterConnectionEstablished(WebSocketSession session) throwsException {session.sendMessage(new TextMessage("欢迎连接到ws服务"));}// 关闭连接@Overridepublic void afterConnectionClosed(WebSocketSession session, CloseStatus status)throws Exception {System.out.println("断开连接！");}
}

3.创建WebSocketConfigurer接口的子类，重写registerWebSocketHandlers方法。

registerWebSocketHandlers()方法参数是WebSocketHandlerRegistry 。调用WebSocketHandlerRegistry 的addHandler方法传递处理器和路径。处理器参数是上一步创建的TextWebSocketHandler 的子类。路径是客户端调用时跟在端口后的路径。再调用WebSocketHandlerRegistry 的setAllowedOrigins方法传递星号，允许跨域访问。

WebSocketHandlerRegistry

addHandler()方法第一个传输传递处理器，第一个参数传递路径
setAllowedOrigins()方法设置允许源，传递星号，否则跨域。

import com.cherry.demo.handler.MyHandler;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {@Autowiredprivate MyHandler myHandler;public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {registry.addHandler(this.myHandler, "/ws").setAllowedOrigins("*");}}

4.使用easyswoole在线工具，测试websocket功能

http://www.easyswoole.com/wstool.html