本文共 7822 字，大约阅读时间需要 26 分钟。

1 配置

1.0 pom.xml

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

1.2 静态文件加载

package com.company.system.config;import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;import org.springframework.web.servlet.config.annotation.InterceptorRegistry;import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;import org.springframework.context.annotation.Configuration;@Configurationpublic class StaticResourceLoadingConfig implements WebMvcConfigurer{       @Override     public void addResourceHandlers(ResourceHandlerRegistry registry){           registry.addResourceHandler("/**")        .addResourceLocations("classpath:/resources/")        .addResourceLocations("classpath:/static/")        .addResourceLocations("classpath:/css");    } }

1.2 websocket配置

package com.company.system.config;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.web.socket.server.standard.ServerEndpointExporter;/** * 开启WebSocket支持 */@Configuration  public class WebSocketConfig {        @Bean      public ServerEndpointExporter serverEndpointExporter() {             return new ServerEndpointExporter();    }  }

2 Websocket路由

package com.company.system.config;import java.io.IOException;import java.util.concurrent.ConcurrentHashMap;import javax.websocket.OnClose;import javax.websocket.OnError;import javax.websocket.OnMessage;import javax.websocket.OnOpen;import javax.websocket.Session;import javax.websocket.server.PathParam;import javax.websocket.server.ServerEndpoint;import com.alibaba.fastjson.JSON;import com.alibaba.fastjson.JSONObject;import org.apache.commons.lang.StringUtils;import org.springframework.stereotype.Component;import org.slf4j.Logger;import org.slf4j.LoggerFactory;@ServerEndpoint("/imserver/{userId}")@Componentpublic class WebSocketServerConfig {       static Logger log=LoggerFactory.getLogger(WebSocketServerConfig.class);    //当前在线连接数    private static int onlineCount = 0;    //concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象    private static ConcurrentHashMap
   
     webSocketMap = new ConcurrentHashMap<>();    //与某个客户端的连接会话，需要通过它来给客户端发送数据    private Session session;    //接收userId    private String userId="";    /**     * 连接建立成功调用的方法*/    @OnOpen    public void onOpen(Session session,@PathParam("userId") String userId) {           this.session = session;        this.userId=userId;        if(webSocketMap.containsKey(userId)){               webSocketMap.remove(userId);            webSocketMap.put(userId,this);            //加入set中        }else{               webSocketMap.put(userId,this);            //加入set中            addOnlineCount();            //在线数加1        }        log.info("用户连接:"+userId+",当前在线人数为:" + getOnlineCount());        try {               sendMessage("我在线上");        } catch (IOException e) {               log.error("用户:"+userId+",网络异常!!!!!!");        }    }    /**     * 连接关闭调用的方法     */    @OnClose    public void onClose() {           if(webSocketMap.containsKey(userId)){               webSocketMap.remove(userId);            //从set中删除            subOnlineCount();        }        log.info("用户退出:"+userId+",当前在线人数为:" + getOnlineCount());    }    /**     * 收到客户端消息后调用的方法     * @param message 发送的信息     * @param session 会话     */    @OnMessage    public void onMessage(String message, Session session) {           log.info("用户消息:"+userId+",报文:"+message);        //可以群发消息        //消息保存到数据库、redis        if(StringUtils.isNotBlank(message)){               try {                   //解析发送的报文                JSONObject jsonObject = JSON.parseObject(message);                //追加发送人(防止串改)                jsonObject.put("fromUserId",this.userId);                String toUserId=jsonObject.getString("toUserId");                //传送给对应toUserId用户的websocket                if(StringUtils.isNotBlank(toUserId)&&webSocketMap.containsKey(toUserId)){                       webSocketMap.get(toUserId).sendMessage(jsonObject.toJSONString());                }else{                       log.error("请求的userId:"+toUserId+"不在该服务器上");                    //否则不在这个服务器上，发送到mysql或者redis                }            }catch (Exception e){                   e.printStackTrace();            }        }    }    /**     * 数据传输错误     * @param session 会话     * @param error 错误     */    @OnError    public void onError(Session session, Throwable error) {           log.error("用户错误:"+this.userId+",原因:"+error.getMessage());        error.printStackTrace();    }        /**     * 服务端向客户端推送消息     * @param message 推送的消息     * @throws IOException 抛出异常     */    public void sendMessage(String message) throws IOException {           this.session.getBasicRemote().sendText(message);    }    /**     * 自定义发送消息     * @param message 发送的消息     * @param userId 用户ID     * @throws IOException 抛出异常     */    public static void sendInfo(String message,@PathParam("userId") String userId) throws IOException {           log.info("发送消息到:"+userId+"，报文:"+message);        if(StringUtils.isNotBlank(userId)&&webSocketMap.containsKey(userId)){               webSocketMap.get(userId).sendMessage(message);        }else{               log.error("用户"+userId+",不在线！");        }    }    public static synchronized int getOnlineCount() {           return onlineCount;    }    public static synchronized void addOnlineCount() {           WebSocketServerConfig.onlineCount++;    }    public static synchronized void subOnlineCount() {           WebSocketServerConfig.onlineCount--;    }}
   

3 自定义回调接口

package com.company.system.controller;import java.util.Map;import java.util.HashMap;import com.company.system.config.WebSocketServerConfig;import org.springframework.http.ResponseEntity;import org.springframework.web.bind.annotation.CrossOrigin;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.PathVariable;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.RequestBody;import org.springframework.web.bind.annotation.ResponseBody;import org.springframework.web.bind.annotation.RestController;import org.springframework.stereotype.Controller;import org.springframework.web.servlet.ModelAndView;import java.io.IOException;@CrossOrigin(origins="*", maxAge=3600)@RequestMapping("/websocket")@Controllerpublic class MsgController {       /**     * web消息发送测试     * @return     */    @GetMapping("/instance/message")    public String page(){           return "websocket/chatpage";    }    /**     * 回调接口,向客户端推送实时消息     * @param params 消息数据结构     * @param toUserId 发动到用户ID     * @return     * @throws IOException 异常     */    @RequestMapping(value="/push/{toUserId}", method=RequestMethod.POST)    @ResponseBody    public Map pushToWeb(@RequestBody Map params,@PathVariable String toUserId) throws IOException {           String message = params.get("message").toString();        WebSocketServerConfig.sendInfo(message,toUserId);        Map returnMap = new HashMap();        returnMap.put("code", 200);        returnMap.put("msg", "成功发送消息");        return returnMap;    }}

4 对话消息展示

4.1 前端html

    
       
   
    
    
当前用户
    
        
    
好友
    
        
    
消息记录
    
    
   
   
    
    
操作
    
    开启socket    
    发送消息
   
   
    
    
消息记录
    
      
   

4.2 对话展示

浏览器打开两个页面,分别访问:http://localhost:10106/websocket/instance/message

4.3 接口推送消息

通过接口给小红发送消息,在用户小红对话框历史中可以看到该条记录:测试消息.

编码后的URL:http://localhost:10106/websocket/push/%E5%B0%8F%E8%8A%B1

【参考文献】

转载地址：http://npht.baihongyu.com/