springboot#整合websocket

        <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.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

package com.websocket.config;

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

@Configuration
public class WebSocketConfig {

    /**
     * 注入一个ServerEndpointExporter,该Bean会自动注册使用@ServerEndpoint注解申明的websocket endpoint
     */
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }

}

package com.websocket.endpoint;

import com.websocket.bean.SessionContext;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;


@Slf4j
@ServerEndpoint(value = "/test/{param}")
@Component
public class CustomWebSocket {

    private static AtomicInteger onlineCount = new AtomicInteger(0);
    public static Map<String, SessionContext> clients = new ConcurrentHashMap<>();


    @OnOpen
    public void onOpen(Session session, @PathParam("param") String param) {

        String queryString = session.getQueryString();
        System.out.println("param is :" + param);
        System.out.println("queryString is = " + queryString);
        
        onlineCount.incrementAndGet(); // 在线数加1
        clients.put(session.getId(), SessionContext.newInstance(session, param));
        log.info("有新连接加入：{}，当前在线数为：{}", session.getId(), onlineCount.get());
    }

    @OnClose
    public void onClose(Session session) {
        onlineCount.decrementAndGet(); // 在线数减1
        clients.remove(session.getId());
        log.info("有一连接关闭：{}，当前在线数为：{}", session.getId(), onlineCount.get());
    }

    @OnMessage
    public void onMessage(String message, Session session) {
        log.info("服务端收到客户端[{}]的消息:{}", session.getId(), message);
    }

    @OnError
    public void onError(Session session, Throwable error) {
        log.error("发生错误");
        error.printStackTrace();
    }
}

package com.websocket;

import com.websocket.endpoint.CustomWebSocket;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

@EnableScheduling
@SpringBootApplication
public class WebsocketApplication {

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

    @Scheduled(cron = "*/2 * * * * *")
    public void run() {
        CustomWebSocket.clients.forEach((k, v)->{
            try {
                v.getSession().getBasicRemote().sendText(v.getParam()+" send @"+new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()));
            } catch (IOException e) {
                e.printStackTrace();
            }
        });
    }

}

package com.websocket.bean;

import lombok.Getter;
import lombok.Setter;

import javax.websocket.Session;

@Getter
@Setter
public class SessionContext {
    private Session session;
    private String param;

    public static SessionContext newInstance(Session session) {
        SessionContext ctx = new SessionContext();
        ctx.setSession(session);
        return ctx;
    }

    public static SessionContext newInstance(Session session,String param) {
        SessionContext ctx = new SessionContext();
        ctx.setSession(session);
        ctx.setParam(param);
        return ctx;
    }
}