WebSocket实现前后端消息推送

环境

jdk8 tomcat7 谷歌浏览器和火狐浏览器（浏览器得支持websocket）
本文用webSocket建立一个简单的聊天室，直接上代码。。。
websocket 用到jar包：

  
        org.springframework  
        spring-websocket  
        ${spring-framework.version}  
      
      
        org.springframework  
        spring-messaging  
        ${spring-framework.version}  
     

先准备一个普通的maven工程 springMVC框架

后台代码：

主要是建立拦截器拦截webSocket请求并交于handler进行处理。
webSocket配置如下：
1.MySocketConfig：注册拦截器+handler

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
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 com.zzm.test.websocket.socket.WebSocketInterceptor;


@Configuration
@EnableWebMvc
@EnableWebSocket
public class MySocketConfig extends WebMvcConfigurerAdapter implements WebSocketConfigurer{

    @Autowired
    private MySocketHandle mySocketHandle;//自己的handler

    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        //注册处理拦截器,拦截url为socketServer的请求
        registry.addHandler(mySocketHandle, "/socketChatroom.do").addInterceptors(new WebSocketInterceptor());//拦截的请求，（注意首先得被servlet拦截到，即要注意web-inf0中的配置）
    }

}

拦截器：拦截请求将httpSession用户保存到WebSocketSession里，用于区别webSocketSession是哪个用户的

import java.util.Map;

import javax.servlet.http.HttpSession;

import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.HandshakeInterceptor;

public class MySocketInterceptor implements HandshakeInterceptor{
    /**
     * 握手后报存用户信息到webSocketSession
     */
    @Override
    public boolean beforeHandshake(ServerHttpRequest request,
            ServerHttpResponse response, WebSocketHandler wsHandler,
            Map attributes) throws Exception {
        if(request instanceof ServerHttpRequest){
              ServletServerHttpRequest servletRequest = (ServletServerHttpRequest) request;
              HttpSession session = servletRequest.getServletRequest().getSession();
              if(session!=null){
                  attributes.put("user", session.getAttribute("user"));
              }
            }
        return true;
    }

    @Override
    public void afterHandshake(ServerHttpRequest request,
            ServerHttpResponse response, WebSocketHandler wsHandler,
            Exception exception) {

    }

}

handler处理类：定义各连接状态的处理，保存连接上的用户，及自定义发送方法

import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.WebSocketMessage;
import org.springframework.web.socket.WebSocketSession;

@Service
public class MySocketHandle implements WebSocketHandler{
    private Logger logger = LoggerFactory.getLogger(MySocketHandle.class);
    private Map users = new ConcurrentHashMap();

    @Override
    public void afterConnectionEstablished(WebSocketSession session)
            throws Exception {
        logger.info("建立socket连接");
        String userName = session.getAttributes().get("user").toString();
        if(null!=userName&&!"".equals(userName)){
            users.put(userName, session);
            session.sendMessage(new TextMessage("system："+userName+"连接成功。。。"));
        }
    }

    @Override
    public void handleMessage(WebSocketSession session,
            WebSocketMessage message) throws Exception {

    }

    @Override
    public void handleTransportError(WebSocketSession session,
            Throwable exception) throws Exception {
        if(session.isOpen()){
            session.close();
        }
        logger.error("连接出现错误",exception);
        users.remove(session.getAttributes().get("user").toString());
    }

    @Override
    public void afterConnectionClosed(WebSocketSession session,
            CloseStatus closeStatus) throws Exception {
        logger.info("连接关闭");
        users.remove(session.getAttributes().get("user").toString());
    }

    @Override
    public boolean supportsPartialMessages() {

        return false;
    }

    public void sendMessageToUsers(String sender,TextMessage message){
        Set> entrySet = users.entrySet();
        for(Map.Entry entry : entrySet){
            String userName = "";
            try{
            userName = entry.getKey();
            if(userName==null||userName.equals(sender)){
                continue;
            }
            WebSocketSession session = entry.getValue();
            session.sendMessage(message);
            }catch(Exception e){
                logger.error("发送信息给"+userName+"失败",e);
            }
        }
    }

    public void sendMessageToUser(String userName,TextMessage message){
        try{
            WebSocketSession session = users.get(userName);
            session.sendMessage(message);
        }catch(Exception e){
            logger.error("发送消息给"+userName+"失败",e);
        }

    }
}

controller类：

import javax.servlet.http.HttpSession;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.socket.TextMessage;

import com.zzm.test.websocket.controller.SocketController;
import com.zzm.test.websocket.service.MySocketHandle;

@Controller
@RequestMapping("socketPushController")
public class SocketPushController {
     private static final Logger logger = LoggerFactory.getLogger(SocketController.class);

      @Autowired
      private MySocketHandle mySocketHandler;

      @RequestMapping("login")
      public String login(HttpSession session,String name){
        logger.info(name+"登录了");

        session.setAttribute("user", name);

        return "../socketPush/chatroom";
      }

      @RequestMapping("sendMessage")
      @ResponseBody
      public String sendMessage(HttpSession session,String message){
          String name = (String) session.getAttribute("user");
          mySocketHandler.sendMessageToUsers( name,new TextMessage(name+" : "+message));
          return "success";
      }
}

前端页面：

登录：用户用姓名登录

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";
%>








    

        姓名：

        
    

发送页面：可以发送和接收信息。

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";
%>










    


    
    
发送

结果图：