Java Springboot websocket使用案例详解

什么是WebSocket

WebSocket是一种在单个TCP连接上进行全双工通信的协议 …

为什么要实现握手监控管理

如果说,连接随意创建,不管的话,会存在错误,broken pipe

表面看单纯报错,并没什么功能缺陷等,但实际,请求数增加,容易导致系统奔溃。这边画重点。

出现原因有很多种,目前我这边出现的原因,是因为客户端已关闭连接,服务端还持续推送导致。

如何使用

下面将使用springboot集成的webSocket

导入Maven

首先SpringBoot版本


    org.springframework.boot
    spring-boot-starter-parent
    1.5.8.RELEASE

集成websocket

// 加个web集成吧

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


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

Java代码

Config配置

首先,我们需要重写WebSocketHandlerDecoratorFactory

主要用来监控客户端握手连接进来以及挥手关闭连接

代码

需要一个管理Socket的类

package com.li.manager;

import lombok.extern.slf4j.Slf4j;
import org.springframework.web.socket.WebSocketSession;

import java.util.concurrent.ConcurrentHashMap;

/**
 * socket管理器
 */
@Slf4j
public class SocketManager {
    private static ConcurrentHashMap manager = new ConcurrentHashMap();

    public static void add(String key, WebSocketSession webSocketSession) {
        log.info("新添加webSocket连接 {} ", key);
        manager.put(key, webSocketSession);
    }

    public static void remove(String key) {
        log.info("移除webSocket连接 {} ", key);
        manager.remove(key);
    }

    public static WebSocketSession get(String key) {
        log.info("获取webSocket连接 {}", key);
        return manager.get(key);
    }


}
package com.li.factory;

import com.li.manager.SocketManager;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.WebSocketHandlerDecorator;
import org.springframework.web.socket.handler.WebSocketHandlerDecoratorFactory;

import java.security.Principal;

/**
 * 服务端和客户端在进行握手挥手时会被执行
 */
@Component
@Slf4j
public class WebSocketDecoratorFactory implements WebSocketHandlerDecoratorFactory {
    @Override
    public WebSocketHandler decorate(WebSocketHandler handler) {
        return new WebSocketHandlerDecorator(handler) {
            @Override
            public void afterConnectionEstablished(WebSocketSession session) throws Exception {
                log.info("有人连接啦  sessionId = {}", session.getId());
                Principal principal = session.getPrincipal();
                if (principal != null) {
                    log.info("key = {} 存入", principal.getName());
                    // 身份校验成功,缓存socket连接
                    SocketManager.add(principal.getName(), session);
                }


                super.afterConnectionEstablished(session);
            }

            @Override
            public void afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus) throws Exception {
                log.info("有人退出连接啦  sessionId = {}", session.getId());
                Principal principal = session.getPrincipal();
                if (principal != null) {
                    // 身份校验成功,移除socket连接
                    SocketManager.remove(principal.getName());
                }
                super.afterConnectionClosed(session, closeStatus);
            }
        };
    }
}
注意:以上session变量,需要注意两点,一个是getId(),一个是getPrincipal().getName()

getId() : 返回的是唯一的会话标识符。

getPrincipal() : 经过身份验证,返回Principal实例,未经过身份验证,返回null

Principal: 委托人的抽象概念,可以是公司id,名字,用户唯一识别token等

当你按上面代码使用,你会发现getPrincipal()返回null,为什么?这边还需要重写一个DefaultHandshakeHandler

代码
package com.li.handler;

import lombok.extern.slf4j.Slf4j;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.support.DefaultHandshakeHandler;

import javax.servlet.http.HttpServletRequest;
import java.security.Principal;
import java.util.Map;

/**
 * 我们可以通过请求信息,比如token、或者session判用户是否可以连接,这样就能够防范非法用户
 */
@Slf4j
@Component
public class PrincipalHandshakeHandler extends DefaultHandshakeHandler {
    @Override
    protected Principal determineUser(ServerHttpRequest request, WebSocketHandler wsHandler, Map attributes) {
        /**
         * 这边可以按你的需求,如何获取唯一的值,既unicode
         * 得到的值,会在监听处理连接的属性中,既WebSocketSession.getPrincipal().getName()
         * 也可以自己实现Principal()
         */
        if (request instanceof ServletServerHttpRequest) {
            ServletServerHttpRequest servletServerHttpRequest = (ServletServerHttpRequest) request;
            HttpServletRequest httpRequest = servletServerHttpRequest.getServletRequest();
            /**
             * 这边就获取你最熟悉的陌生人,携带参数,你可以cookie,请求头,或者url携带,这边我采用url携带
             */
            final String token = httpRequest.getParameter("token");
            if (StringUtils.isEmpty(token)) {
                return null;
            }
            return new Principal() {
                @Override
                public String getName() {
                    return token;
                }
            };
        }
        return null;
    }
}
需要的东西都有了,那准备装载吧
代码
package com.li.config;

import com.li.factory.WebSocketDecoratorFactory;
import com.li.handler.PrincipalHandshakeHandler;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.web.socket.config.annotation.AbstractWebSocketMessageBrokerConfigurer;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
import org.springframework.web.socket.config.annotation.WebSocketTransportRegistration;


/**
 * WebSocketConfig配置
 */
@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer {

    @Autowired
    private WebSocketDecoratorFactory webSocketDecoratorFactory;
    @Autowired
    private PrincipalHandshakeHandler principalHandshakeHandler;

    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        /**
         * myUrl表示 你前端到时要对应url映射
         */
        registry.addEndpoint("/myUrl")
                .setAllowedOrigins("*")
                .setHandshakeHandler(principalHandshakeHandler)
                .withSockJS();
    }

    @Override
    public void configureMessageBroker(MessageBrokerRegistry registry) {
        /**
         * queue 点对点
         * topic 广播
         * user 点对点前缀
         */
        registry.enableSimpleBroker("/queue", "/topic");
        registry.setUserDestinationPrefix("/user");
    }

    @Override
    public void configureWebSocketTransport(WebSocketTransportRegistration registration) {
        registration.addDecoratorFactory(webSocketDecoratorFactory);
        super.configureWebSocketTransport(registration);
    }
}

终于完成了

最后,来一个通过http请求,将其发送到客户端

代码
package com.li.controller;

import com.li.manager.SocketManager;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.messaging.handler.annotation.MessageMapping;
import org.springframework.messaging.handler.annotation.SendTo;
import org.springframework.messaging.simp.SimpMessagingTemplate;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.socket.WebSocketSession;

import java.util.Map;

@RestController
@Slf4j
public class TestController {

    @Autowired
    private SimpMessagingTemplate template;

    /**
     * 服务器指定用户进行推送,需要前端开通 var socket = new SockJS(host+'/myUrl' + '?token=1234');
     */
    @RequestMapping("/sendUser")
    public void sendUser(String token) {
        log.info("token = {} ,对其发送您好", token);
        WebSocketSession webSocketSession = SocketManager.get(token);
        if (webSocketSession != null) {
            /**
             * 主要防止broken pipe
             */
            template.convertAndSendToUser(token, "/queue/sendUser", "您好");
        }

    }

    /**
     * 广播,服务器主动推给连接的客户端
     */
    @RequestMapping("/sendTopic")
    public void sendTopic() {
        template.convertAndSend("/topic/sendTopic", "大家晚上好");

    }

    /**
     * 客户端发消息,服务端接收
     *
     * @param message
     */
    // 相当于RequestMapping
    @MessageMapping("/sendServer")
    public void sendServer(String message) {
        log.info("message:{}", message);
    }

    /**
     * 客户端发消息,大家都接收,相当于直播说话
     *
     * @param message
     * @return
     */
    @MessageMapping("/sendAllUser")
    @SendTo("/topic/sendTopic")
    public String sendAllUser(String message) {
        // 也可以采用template方式
        return message;
    }

    /**
     * 点对点用户聊天,这边需要注意,由于前端传过来json数据,所以使用@RequestBody
     * 这边需要前端开通var socket = new SockJS(host+'/myUrl' + '?token=4567');   token为指定name
     * @param map
     */
    @MessageMapping("/sendMyUser")
    public void sendMyUser(@RequestBody Map map) {
        log.info("map = {}", map);
        WebSocketSession webSocketSession = SocketManager.get(map.get("name"));
        if (webSocketSession != null) {
            log.info("sessionId = {}", webSocketSession.getId());
            template.convertAndSendToUser(map.get("name"), "/queue/sendUser", map.get("message"));
        }
    }


}

前端代码

可以直接启动





Spring Boot WebSocket+广播式


    
    

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