websocket 点对点、广播推送

废话就不多说了。

1、springboot项目引入websocket依赖

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

2、springbooot在启动类中注入 ServerEndpointExporter

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

3、Websocket组件类

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

import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.atomic.AtomicInteger;

@Component
@ServerEndpoint("/websocket/{sessionId}")
public class WebSocket {

    private static final Logger logger = LoggerFactory  .getLogger(WebSocket.class);

    private static final AtomicInteger onlineCount = new AtomicInteger(0);

    private Session session;

    private static CopyOnWriteArraySet<WebSocket> webSockets = new CopyOnWriteArraySet<>();

    private String sessionId="";

    @OnOpen
    public void onOpen(Session session,@PathParam("sessionId") String sessionId) {
        this.session = session;
        this.sessionId=sessionId;
        webSockets.add(this);
        int count = onlineCount.incrementAndGet(); // 在线数加1
        logger.info("有连接加入，当前连接数为:{}", count);
        sendMessage("0");

    }

    /**
     * 关闭调用方法
     */
    @OnClose
    public void onClose() {
        webSockets.remove(this);
        int count = onlineCount.decrementAndGet();
        logger.info("有连接关闭，当前连接数为:{}", count);
    }

    @OnError
    public void onError(Session session, Throwable error) {
        logger.error("发生错误：{}，Session ID： {}",error.getMessage(),session.getId());
        error.printStackTrace();
    }

    @OnMessage
    public void onMessage(String message, Session session) {
        logger.info("收到来自客户"+sessionId+"的信息:{}", message);
        sendMessage(message);
    }

    /**
     * 实现服务器主动推送
     */
    public void sendMessage(String message){
        try {//推送消息和当前socket通道的会话id (客户)
            this.session.getBasicRemote().sendText(message +"=="+ sessionId);
        } catch (IOException e) {
            logger.error("websocket异常: "+ e.toString());
        }
    }


    public static void sendInfo(String message,@PathParam("sessionId") String sessionId){
        logger.info("推送消息到窗口"+sessionId+"，推送内容:"+message);
        for (WebSocket item : webSockets) {
                //这里可以设定只推送给这个sid的，为null则全部推送
                if(sessionId==null) {
                    item.sendMessage(message);
                }else if(item.sessionId.equals(sessionId)){
                    item.sendMessage(message);
                }
        }

    }

    /**
     * 消息广播到前台
     *
     * @param message
     */
    public void sendAllMessage(String message) {
        for (WebSocket webSocket : webSockets) {
            try {
                webSocket.session.getBasicRemote().sendText(message);
            } catch (IOException e) {
                logger.error("websocket异常: "+ e.toString());
            }
        }
    }

}

4、测试方法点对点推送，偶数给客户a推送奇数给客户b推送推荐一个在线websocket测试工具：戳这里

    @Autowired
    private WebSocket webSocket;

    @RequestMapping(value = "/test", method = RequestMethod.POST, produces = "application/json;charset=utf-8")
    public String test(){
        String sessionId = "";

        for(int i=0;i<8;i++){
            JSONObject js = new JSONObject();
            js.put("isHasNewMessage", i);
            if (i %2 ==0){
                sessionId = "a";
            }else{
                sessionId ="b";
            }
            webSocket.sendInfo(js.toString(), sessionId);
        }
        return "成功";
    }

输入本机websocket地址 ws://ip:port/websocket/{} 说明 /websocket/{} 是websocket组件类的@ServerEndpoint("/websocket/{sessionId}") 中指明的路径后缀

如图,现在建立a客户的socket连接通道

再建立b客户的socket连接通道

然后postman调用测试方法 http://localhost:8080/test, 分别查看客户a和客户b的消息推送结果

客户a：

客户b：

5、测试方法广播推送，所有数据给客户a、客户b推送

    @Autowired
    private WebSocket webSocket;

    @RequestMapping(value = "/test", method = RequestMethod.POST, produces = "application/json;charset=utf-8")
    public String test(){
        String sessionId = "";

        for(int i=0;i<8;i++){
            JSONObject js = new JSONObject();
            js.put("isHasNewMessage", i);
            if (i %2 ==0){
                sessionId = "a";
            }else{
                sessionId ="b";
            }
            webSocket.sendAllMessage(js.toString());
        }
        return "成功";
    }

同样的，先建立两个客户a和客户b的连接，这里就不在重复操作截图了，直接调用测试方法，然后看客户a、客户b是否收到了消息

客户a