https://blog.csdn.net/u013565163/article/details/80659828
SpringBoot+websocket+定时任务
SpringBoot+websocket概念websocket:由于http协议时基于 请求-响应模型 服务端的每次响应都必须有客户端发起(浏览器)的请求。如果服务端想主动推送消息到客户端是很难满足的。 如果一定想使用http来做服务端主动推动,只能客户端不停的发起轮询请求,如果访问量很很大,这种模式会拖垮服务器。造成很大的通信开销和服务端流量压力。使用websocket可以完成要求实时性的应用:股票的变动、天气、彩票、即时通讯、通知。
WebSocket 是web客户端和服务器之间新的通讯方式, 依然架构在HTTP协议之上。使用WebSocket连接, web应用程序可以执行实时的交互, 而不是以前的poll方式。
WebSocket是HTML5开始提供的一种在单个 TCP 连接上进行全双工通讯的协议,可以用来创建快速的更大规模的健壮的高性能实时的web应用程序。WebSocket通信协议于2011年被IETF定为标准RFC 6455,WebSocketAPI被W3C定为标准。
在WebSocket API中,浏览器和服务器只需要做一个握手的动作,然后,浏览器和服务器之间就形成了一条快速通道。两者之间就直接可以数据互相传送。现在大概了解了websocket的概念和应用,现在我们来看看如何在springBoot中集成websocket。
配置类
创建一个配置类: 使用@Configuration注解 声明这个类为配置类。 使用@EnableWebSocket注解表明这是一个websocket配置类,我们会在这个类配置一些websocket的参数和地址。 我们的配置类实现WebSocketConfigurer接口。重写registerWebSocketHandlers方法,
//配置指定地址:/demo的处理器,及通信允许的域名,这里使用*,表示匹配所有。
webSocketHandlerRegistry.addHandler(new WebSocketDemoHanlder(),"/demo").setAllowedOrigins("*"); /** * @author xuelongjiang */@Configuration@EnableWebSocketpublic class WebsocketConfig implements WebSocketConfigurer{@Override
public void registerWebSocketHandlers(WebSocketHandlerRegistry webSocketHandlerRegistry) { webSocketHandlerRegistry.addHandler(new WebSocketDemoHanlder(),"/demo").setAllowedOrigins("*");}}处理器这里我们主要绑定WebSocketSession和我们的推送目标。如果是聊天室,则根据约定的规则,进行用户与用户,用户与聊天室的绑定。
如果是彩票,推送消息到所有的WebSocketSession。
package com.xuelongjiang.websocketdemo.websocket;
import com.alibaba.fastjson.JSONObject;
import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.web.socket.CloseStatus;import org.springframework.web.socket.TextMessage;import org.springframework.web.socket.WebSocketSession;import org.springframework.web.socket.handler.TextWebSocketHandler;import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;/**
* @author xuelongjiang*/public class WebSocketDemoHanlder extends TextWebSocketHandler {
private Logger logger = LoggerFactory.getLogger(WebSocketDemoHanlder.class);
private static Map<String,WebSocketSession> userIdSessionMap = new ConcurrentHashMap();
private static Map<WebSocketSession,String> sessionUserIdMap = new ConcurrentHashMap<>(); @Overrideprotected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {String payload = message.getPayload();
logger.info("websocket请求参数payload:{}",payload); JSONObject jsonObject = JSONObject.parseObject(payload); String action = jsonObject.getString("action");if("register".equals(action)){
logger.info("注册websocket连接"); String userId = jsonObject.getString("userId"); logger.info("userId:{}注册session:{}",userId,session.getId()); userIdSessionMap.put(userId,session); sessionUserIdMap.put(session,userId); }}//定时任务获取session
public static Map<String,WebSocketSession> getUserIdSessionMap(){ return userIdSessionMap;}@Override
public void afterConnectionEstablished(WebSocketSession session) throws Exception { super.afterConnectionEstablished(session);}@Override
public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {//连接关闭后移除
String userId = sessionUserIdMap.get(session); userIdSessionMap.remove(userId); logger.info("websocket session:{}关闭原因:{}",session,status);}}到这里我们测试一下是否可以连接。
从上面可以看到我们已经和服务端建立了连接。
websocketSession:可以理解为http的一个会话。会话记录了这一次的通讯对象,我们可以使用seesion发送消息给客户端。
定时任务
在上面我们用一个线程安全的map,存储了userId和websocketSession的关系。现在我们用定时任务来发送消息给连接。在springboot启动类增加注解@EnableScheduling
由于websocket和定时任务启动的时候会报错。的时候会报错。增加taskScheduler()方法。@SpringBootApplication
@EnableSchedulingpublic class WebsocketdemoApplication {public static void main(String[] args) {
SpringApplication.run(WebsocketdemoApplication.class, args);} /** * 使用 websockt注解的时候,使用@EnableScheduling注解 * 启动的时候一直报错,增加这个bean 则报错解决。 * 报错信息: Unexpected use of scheduler. *https://stackoverflow.com/questions/49343692/websocketconfigurer-and-scheduled-are-not-work-well-in-an-application * * @return */@Beanpublic TaskScheduler taskScheduler(){ThreadPoolTaskScheduler taskScheduler = new ThreadPoolTaskScheduler();
taskScheduler.setPoolSize(10); taskScheduler.initialize(); return taskScheduler; }}定时任务package com.xuelongjiang.websocketdemo.schedule;import com.xuelongjiang.websocketdemo.websocket.WebSocketDemoHanlder;
import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.scheduling.annotation.Scheduled;import org.springframework.stereotype.Service;import org.springframework.web.socket.TextMessage;import org.springframework.web.socket.WebSocketSession;import java.util.Map;
/**
* 定时任务 * @author xuelongjiang */@Servicepublic class ScheduleTask {private Logger logger = LoggerFactory.getLogger(ScheduleTask.class);
@Scheduled(cron = "* * 0/1 * * ?")
public void sendMessage(){String message = "你好";
Map<String,WebSocketSession> map = WebSocketDemoHanlder.getUserIdSessionMap();
WebSocketSession session = map.get("xuelongjiang");//这里用户ID的获取可以根据具体业务,这里为了更简单的演示。
if(session != null){ try { session.sendMessage(new TextMessage(message)); }catch (Exception e){ logger.error("定时任务异常:{}",e); } }}} websocket测试地址:http://www.blue-zero.com/WebSocket/ 源码地址:https://github.com/longjiangxue/websocketDemo--------------------- 作者:我爱看明朝 来源:CSDN 原文:https://blog.csdn.net/u013565163/article/details/80659828 版权声明:本文为博主原创文章,转载请附上博文链接!
SpringMVC 使用websocket向前端实时推送信息
一、maven项目添加websocket依赖
在pom.xml中添加依赖 二、项目中添加websocket相关配置 1、创建一个WebSocket配置类(这里也可以用配置文件来实现其实),实现接口来配置Websocket请求的路径和拦截器package com.example.websocket;
import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.stereotype.Component;
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;@Configuration@EnableWebSocketpublic class WebSocketConfig implements WebSocketConfigurer {@Override
public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) { registry.addHandler(myHandler(), "/myHandler").addInterceptors(new WebSocketInterceptor()).setAllowedOrigins("*"); }@Bean
public WebSocketHandler myHandler() { return new MyHandler(); }}
加个setAllowedOrigins(“*”)不然可能会报403的错误3、创建拦截器,用来记录用户标识,便于后面向特定用户发送消息
package com.example.websocket;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;import org.springframework.http.server.ServletServerHttpRequest;import org.springframework.stereotype.Component;import org.springframework.web.socket.WebSocketHandler;import org.springframework.web.socket.server.HandshakeInterceptor;import javax.servlet.http.HttpSession;
import java.util.Map;@Component
public class WebSocketInterceptor implements HandshakeInterceptor {@Override
public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler handler, Map<String, Object> map) throws Exception { if (request instanceof ServletServerHttpRequest) { ServletServerHttpRequest serverHttpRequest = (ServletServerHttpRequest) request; HttpSession session = serverHttpRequest.getServletRequest().getSession(); if (session != null) { map.put("username", session.getAttribute("username")); }}
return true; }@Override
public void afterHandshake(ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse, WebSocketHandler webSocketHandler, Exception e) {}
}4、实现Websocket建立连接、发送消息、断开连接等时候的处理类。package com.example.websocket;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;import org.springframework.web.socket.CloseStatus;import org.springframework.web.socket.TextMessage;import org.springframework.web.socket.WebSocketMessage;import org.springframework.web.socket.WebSocketSession;import org.springframework.web.socket.handler.TextWebSocketHandler;import java.io.IOException;
import java.util.HashMap;import java.util.Map;import java.util.Set;@Service
public class MyHandler extends TextWebSocketHandler { //在线用户列表 private static final Map<String, WebSocketSession> users; //用户标识 private static final String CLIENT_ID = "username";static {
users = new HashMap<String, WebSocketSession>(); }@Override
public void afterConnectionEstablished(WebSocketSession session) throws Exception { System.out.println("成功建立连接"); String username= getClientId(session); System.out.println("5555"+username); if (username != null) { users.put(username, session); session.sendMessage(new TextMessage("成功建立socket连接")); System.out.println(username); System.out.println(session); } }@Override
public void handleTextMessage(WebSocketSession session, TextMessage message) { // ... System.out.println(message.getPayload());WebSocketMessage message1 = new TextMessage("server:"+message);
try { session.sendMessage(message1); } catch (IOException e) { e.printStackTrace(); } }/**
* 发送信息给指定用户 * @param clientId * @param message * @return */ public boolean sendMessageToUser(String clientId, TextMessage message) { if (users.get(clientId) == null) { System.out.println("1313313"); return false; } WebSocketSession session = users.get(clientId); System.out.println("sendMessage:" + session); if (!session.isOpen()) { System.out.println("7657"); return false; } try { session.sendMessage(message); } catch (IOException e) { System.out.println(e); return false; } return true; }/**
* 广播信息 * @param message * @return */ public boolean sendMessageToAllUsers(TextMessage message) { boolean allSendSuccess = true; Set<String> clientIds = users.keySet(); WebSocketSession session = null; for (String clientId : clientIds) { try { session = users.get(clientId); if (session.isOpen()) { session.sendMessage(message); } } catch (IOException e) { e.printStackTrace(); allSendSuccess = false; } }return allSendSuccess;
} @Override public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception { if (session.isOpen()) { session.close(); } System.out.println("连接出错"); users.remove(getClientId(session)); }@Override
public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception { System.out.println("连接已关闭:" + status); users.remove(getClientId(session)); }@Override
public boolean supportsPartialMessages() { return false; }/**
* 获取用户标识 * @param session * @return */ private String getClientId(WebSocketSession session) { try { String clientId = (String) session.getAttributes().get(CLIENT_ID); return clientId; } catch (Exception e) { return null; } }}5、controller@Controller
public class SocketController {@Autowired
MyHandler handler; @RequestMapping("/login/{username}") public @ResponseBody String login(HttpSession session, @PathVariable("username") String username) { System.out.println("登录接口,username="+usename); session.setAttribute("username", username); System.out.println(session.getAttribute("username"));return "成功";
}@RequestMapping("/message")
public @ResponseBody String sendMessage() { boolean flag = handler.sendMessageToAllUser(4, new TextMessage("你好")); System.out.println(flag); return "发送"; }}
6、前端//建立websocket
var ws = new WebSocket("ws://localhost:8080/你的项目名/myHandler")--------------------- 作者:HOMERUNIT 来源:CSDN 原文:https://blog.csdn.net/HOMERUNIT/article/details/80861096 版权声明:本文为博主原创文章,转载请附上博文链接!