SpringMVC WebSocket实现消息推送

╰半橙微兮° 2022-02-27 02:30 458阅读 0赞

## 第一步： 添加Spring WebSocket的依赖jar包 ##

<dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-websocket</artifactId>
          <version>${spring-framework.version}</version>
      </dependency>
      <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-messaging</artifactId>
          <version>${spring-framework.version}</version>
      </dependency>

## 第二步：建立一个类实现WebSocketConfigurer接口 ##

package com.my.spring.context;
    
    import com.my.business.spring.SpringWebSocketHandler;
    import lombok.AllArgsConstructor;
    import org.springframework.context.annotation.Bean;
    import org.springframework.web.servlet.config.annotation.EnableWebMvc;
    import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;
    import org.springframework.web.socket.config.annotation.EnableWebSocket;
    import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
    import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
    import org.springframework.web.socket.handler.TextWebSocketHandler;
    import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;
    
    import java.util.HashMap;
    
    /** * Spring Context - web socket配置 * @author my Team * @version 2.0 * @see com.my.business.spring.SpringWebSocketHandler */
    @AllArgsConstructor(onConstructor = @__({ @Autowired}))
    @EnableWebMvc
    @EnableWebSocket
    public class SpringWebSocketConfig extends WebMvcConfigurationSupport implements WebSocketConfigurer { 
    
        @Override
        public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) { 
    		//HttpSessionHandshakeInterceptor拦截器，可以自定义，由于系统实现了session登录，这里就不需要再实现session与用户的绑定。
            registry.addHandler(webSocketHandler(), "/websocket").addInterceptors(new HttpSessionHandshakeInterceptor());
            registry.addHandler(webSocketHandler(), "/sockjs").addInterceptors(new HttpSessionHandshakeInterceptor()).withSockJS();
        }
    
        @Bean
        public TextWebSocketHandler webSocketHandler(){ 
            SpringWebSocketHandler springWebSocketHandler = new SpringWebSocketHandler();
            return springWebSocketHandler;
        }
    }

## 第三步：继承WebSocketHandler对象。 ##

实现websocket的登录、关闭、异常、发送消息等方法。

package com.my.business.spring;
    
    import com.my.business.entity.Person;
    import com.my.business.model.Principal;
    import com.my.business.service.PersonService;
    import com.my.spring.context.ApplicationUtils;
    import com.my.spring.core.Assert;
    import lombok.Setter;
    import org.apache.shiro.subject.SimplePrincipalCollection;
    import org.apache.shiro.subject.support.DefaultSubjectContext;
    import org.springframework.web.socket.CloseStatus;
    import org.springframework.web.socket.TextMessage;
    import org.springframework.web.socket.WebSocketSession;
    import org.springframework.web.socket.adapter.standard.StandardWebSocketSession;
    import org.springframework.web.socket.handler.TextWebSocketHandler;
    
    import java.io.IOException;
    import java.util.Date;
    import java.util.HashMap;
    import java.util.Map;
    import java.util.Set;
    import java.util.concurrent.TimeUnit;
    
    /** * websocket 发送消息 */
    public class SpringWebSocketHandler extends TextWebSocketHandler { 
    
        @Setter
        private static Map<Long, WebSocketSession> sessionMap = new HashMap<>();
    
        /** * 连接成功的时候，触发页面上onopen方法 * @param session session * @throws Exception 异常 */
        @Override
        public void afterConnectionEstablished(WebSocketSession session) throws Exception { 
            Person person = getLoginer(session);
            Assert.notNull(person);
            sessionMap.put(person.getId(), session);
            //TODO 发送离线消息
        }
    
        @Override
        public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception { 
            Person person = getLoginer(session);
            Assert.notNull(person);
            sessionMap.remove(person.getId());
        }
    
        @Override
        public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception { 
            if (session.isOpen()) { 
                session.close();
            }
            Person person = getLoginer(session);
            if (person != null) { 
                sessionMap.remove(person.getId());
            }
        }
    
        /** * 获取当前登录人。这里直接获取用户登录拦截器所存入的用户session * @param session session * @return 登录人 */
        private Person getLoginer(WebSocketSession session) { 
            Assert.notNull(session);
            SimplePrincipalCollection simplePrincipalCollection = (SimplePrincipalCollection) session.getAttributes().get(DefaultSubjectContext.PRINCIPALS_SESSION_KEY);
            if (simplePrincipalCollection == null) { 
                return null;
            }
            Set<Object> objectSet = simplePrincipalCollection.asSet();
            for (Object object : objectSet) { 
                if (object instanceof Principal) { 
                    Principal principal = (Principal) object;
                    return ApplicationUtils.getBean(PersonService.class).findByUser(principal.getSn());
                }
            }
            return null;
        }
    
        /** * 发送消息 * @param session session * @param message 消息内容 */
        private boolean sendMessage(WebSocketSession session, TextMessage message) throws IOException { 
            Assert.notNull(session);
            Assert.notNull(message);
            if (session.isOpen()) { 
                session.sendMessage(message);
                return true;
            } else { 
                return false;
            }
        }
    
        /** * 向用户发送消息 * @param personId 用户id * @param message message * @return */
        public boolean sendMessageToUser(Long personId, String message) { 
            Assert.notNull(personId);
            Assert.notEmpty(message);
            WebSocketSession session = sessionMap.get(personId);
            if (session == null) { 
                return false;
            }
            TextMessage textMessage = new TextMessage(message);
            try { 
                return sendMessage(session, textMessage);
            } catch (IOException e) { 
                e.printStackTrace();
                return false;
            }
        }
    }

## 第四部 测试代码 ##

**HTML代码**

<!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
    
    <script src="./resources/js/jquery-1.11.3.min.js"></script>
    <script src="./resources/js/sockjs.js"></script>
    <script> var websocket = null; if ('WebSocket' in window) { websocket = new WebSocket("ws://localhost:8801/websocket"); } else if ('MozWebSocket' in window) { websocket = new MozWebSocket("ws://localhost:8801/websocket"); } else { websocket = new SockJS("http://localhost:8801/sockjs"); } websocket.onopen = onOpen; websocket.onmessage = onMessage; websocket.onerror = onError; websocket.onclose = onClose; function onOpen(openEvt) { //alert(openEvt.Data); } //接收消息方法 function onMessage(evt) { alert(evt.data); } function onError() { } function onClose() { } //发送消息 function doSend() { if (websocket.readyState == websocket.OPEN) { var msg = document.getElementById("inputMsg").value; websocket.send(msg);//调用后台handleTextMessage方法 alert("发送成功!"); } else { alert("连接失败!"); } } window.close=function() { websocket.onclose(); } </script>
    </body>
    </html>

**java代码**

package com.my.business.controller;
    
    import com.my.business.model.Pageable;
    import com.my.business.service.PersonService;
    import com.my.business.spring.SpringWebSocketHandler;
    import lombok.AllArgsConstructor;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.ModelMap;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    @AllArgsConstructor(onConstructor = @__({ @Autowired}))
    @Controller
    @RequestMapping("/test")
    public class TestController { 
        private PersonService personService;
        private SpringWebSocketHandler webSocketHandler;
    
        @RequestMapping(method = RequestMethod.GET)
        public String test(String name, ModelMap model) { 
            model.addAttribute("name", name);
            model.addAttribute("persons", personService.findPage(new Pageable()).getContent());
            return "/test";
        }
    
        @ResponseBody
        @RequestMapping(value = "/name", method = RequestMethod.GET)
        public boolean name(String name) { 
            return webSocketHandler.sendMessageToUser(personService.findLoginer().getId(), "你好socket");
        }
    }

先访问http://localhost:8801/test返回页面，创建WebSocket连接，再访问http://localhost:8801/test/name向当前用户发送消息。

[代码及sockjs.js下载][sockjs.js]

本文参考：[https://www.cnblogs.com/3dianpomian/p/5902084.html][https_www.cnblogs.com_3dianpomian_p_5902084.html]

[sockjs.js]: https://download.csdn.net/download/michean/11061441
[https_www.cnblogs.com_3dianpomian_p_5902084.html]: https://www.cnblogs.com/3dianpomian/p/5902084.html