19-springboot实现websocket

1 创建项目，添加依赖库，修改pom.xml

      org.springframework.boot
      spring-boot-starter-web
      2.4.2


       org.projectlombok
       lombok
       1.18.20
       provided

  
       org.springframework.boot
       spring-boot-starter-websocket
       2.3.5.RELEASE
  

2 创建WebSocket配置类

package com.demo.cfg;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
import javax.annotation.Resource;

/**
 * 代码描述: websocket配置类
 *
 * @author wujianping
 * @since 2022/5/16 14:25
 */
@EnableWebSocket
@Configuration
public class WebSocketConfig implements WebSocketConfigurer {
    @Resource
    WebSocketHandler defaultHandler;
    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        registry.addHandler(defaultHandler, "/ws").addInterceptors().setAllowedOrigins("*");
    }
}

3 创建websocket操作句柄

package com.demo.handler;

import org.springframework.stereotype.Component;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.WebSocketMessage;
import org.springframework.web.socket.WebSocketSession;

/**
 * 代码描述: 自定义处理器需要实现 WebSocketHandler 接口
 *
 * @author wujianping
 * @since 2022/5/16 14:28
 */
@Component
public class DefaultHandler implements WebSocketHandler {

    /**
     * 建立连接
     * @param session
     * @throws Exception
     */
    @Override
    public void afterConnectionEstablished(WebSocketSession session) throws Exception {
        // 缓存用户信息: userInfo
    }

    /**
     * 接收消息
     * @param session
     * @param message
     * @throws Exception
     */
    @Override
    public void handleMessage(WebSocketSession session, WebSocketMessage message) throws Exception {
    }

    /**
     * 发生错误
     * @param session
     * @param exception
     * @throws Exception
     */
    @Override
    public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
        // 清除用户缓存信息
    }

    /**
     * 关闭连接
     * @param session
     * @param closeStatus
     * @throws Exception
     */
    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus) throws Exception {
        // 清除用户缓存信息
    }

    @Override
    public boolean supportsPartialMessages() {
        return false;
    }
}

4 创建拦截器

package com.demo.handler;

import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.HandshakeInterceptor;

import java.util.Map;

/**
 * 代码描述: 拦截器可以在 websocket 连接握手阶段做一些校验，还可以存储用户的连接信息,返回 false 拒绝连接，true 则通过
 *
 * @author wujianping
 * @since 2022/5/16 14:29
 */
@Component
public class DefaultInterceptor implements HandshakeInterceptor {
    @Override
    public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Map attributes) throws Exception {
        // TODO
        return false; // [1]
    }

    @Override
    public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Exception exception) {

    }
}

5 创建测试页面

   
   
   
    
      
        
   
   
   
      

         运行 WebSocket