webSocket实时通信02——基于Spring【纯后端——JAVA】

这里是基于Spring整合websoket后来实现的实时通信，这里只有java的代码，通过在线网站 http://www.websocket-test.com/测试即可

1. 导包

	<dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-websocket</artifactId>
      <version>2.1.6.RELEASE</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>5.1.8.RELEASE</version>
    </dependency>
	
	<dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
      <version>2.1.6.RELEASE</version>
    </dependency>

2. 拦截器

public class MyHandshakeInterceptor implements HandshakeInterceptor {

    /**
     * 握手前 可进行业务逻辑处理 例如用户校验啥的
     * @param serverHttpRequest
     * @param serverHttpResponse
     * @param webSocketHandler
     * @param map
     * @return
     * @throws Exception
     */
    @Override
    public boolean beforeHandshake(ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse, WebSocketHandler webSocketHandler, Map<String, Object> map) throws Exception {
        return true;
    }

    /**
     * 握手后
     * @param serverHttpRequest
     * @param serverHttpResponse
     * @param webSocketHandler
     * @param e
     */
    @Override
    public void afterHandshake(ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse, WebSocketHandler webSocketHandler, Exception e) {

    }
}

3. 处理器

可以用set来存储客户端对象，也可以用map来存储，具体根据实际场景来就行，在onOpen()等几个方法中，具体的代码根据自己的业务逻辑来实现即可。

public class MyWebSocketHandler implements WebSocketHandler {

    /**
     * 用来存储每一个客户端对象对应的WebSocketSession对象
     */
    private static final Set<WebSocketSession> users = new CopyOnWriteArraySet<>();

    /**
     * 链接成功之后的处理
     */
    @Override
    public void afterConnectionEstablished(WebSocketSession webSocketSession) throws Exception {
        users.add(webSocketSession);
        System.out.println(webSocketSession.hashCode() + "建立连接成功");
    }

    /**
     * 服务器接收到消息的处理
     * @param webSocketSession
     * @param webSocketMessage
     * @throws Exception
     */
    @Override
    public void handleMessage(WebSocketSession webSocketSession, WebSocketMessage<?> webSocketMessage) throws Exception {
        try {
            webSocketSession.sendMessage(new TextMessage("接收到消息：" + webSocketMessage.getPayload()));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 推送消息给所有人
     * @param text
     */
    public static void sendMsgToAll(String text) {
        for (WebSocketSession session : users) {
            try {
                session.sendMessage(new TextMessage(text));
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 连接异常的处理
     * @param webSocketSession
     * @param throwable
     * @throws Exception
     */
    @Override
    public void handleTransportError(WebSocketSession webSocketSession, Throwable throwable) throws Exception {
        System.out.println(webSocketSession.hashCode() + "连接异常");
        throwable.printStackTrace();
    }

    /**
     * 连接关闭时的处理
     * @param webSocketSession
     * @param closeStatus
     * @throws Exception
     */
    @Override
    public void afterConnectionClosed(WebSocketSession webSocketSession, CloseStatus closeStatus) throws Exception {
        users.remove(webSocketSession);
        System.out.println(webSocketSession.hashCode() + "连接关闭");
    }

	/**
     * 是否支持分片消息
     * @return
     */
    @Override
    public boolean supportsPartialMessages() {
        return false;
    }
}

4. 配置类

这里用一个接口来推送消息给所有连接到服务器的客户端

@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {
    /**
     * 配置服务器的ws地址 跨域校验
     * @param webSocketHandlerRegistry
     */
    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry webSocketHandlerRegistry) {
        webSocketHandlerRegistry.addHandler(myWebSocketHandler(), "/webSocketBySpring").addInterceptors(new MyHandshakeInterceptor()).setAllowedOrigins("*");
        webSocketHandlerRegistry.addHandler(myWebSocketHandler(), "/sockjs/webSocketBySpring").addInterceptors(new MyHandshakeInterceptor()).setAllowedOrigins("*").withSockJS();
    }

    @Bean
    public WebSocketHandler myWebSocketHandler() {
        return new MyWebSocketHandler();
    }
}

5. 控制器

@RestController
public class MsgController2 {

    @GetMapping("/sendMsg")
    public void sendMsg(@RequestParam(value = "text") String text) {
        MyWebSocketHandler.sendMsgToAll(text);
    }
}

6. 启动类

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

7. 测试

1. 使用不同的浏览器访问http://www.websocket-test.com/
   进入到网页后会自动连接到网站系统的websocket服务器，这需要我们先断开连接，将地址填成我们的地址
   
   链接成功调用afterConnectionEstablished()
   

2. 通过定义的接口推送消息
   直接通过浏览器调用本地地址http://192.168.16.144:8800/sendMsg?text=你是来拉屎的吗