HTML5 WebSocket+Tomcat8实现真●Web版即时聊天室(单人+多人)

之前做了一篇tomcat7的websocket聊天室，这是基于tomcat7和jdk1.7下的，有的项目是在tomcat8下的，这个时候就会有问题，因为8下面不支持那种写法，它是以注解的方式来实现websocket，参照HTML5 WebSocket+Tomcat实现Web版即时聊天室 ，下面就介绍一下如何在8下面实现聊天室，多人加单人！
最重要的是获取每个用户登录的session，这里的session是HttpSession，websocket自带了session，但在实际项目中我们可能只用到第一种，如何在8下面获取呢？
这里要写个类，来继承ServerEndpointConfig.Configurator：

package com.socket;

import javax.websocket.HandshakeResponse;
import javax.websocket.server.HandshakeRequest;
import javax.websocket.server.ServerEndpointConfig;

import javax.servlet.http.HttpSession;

public class GetHttpSessionConfigurator extends ServerEndpointConfig.Configurator  {

    @Override
    public void modifyHandshake(ServerEndpointConfig config,HandshakeRequest request, HandshakeResponse response) {
        HttpSession httpSession = (HttpSession) request.getHttpSession();
        config.getUserProperties().put(HttpSession.class.getName(), httpSession);
    }

}

再在websocket服务里添加这个配置，就像这样

@ServerEndpoint(value = /websocket,configurator=GetHttpSessionConfigurator.class)

我将两个HttpSession放在一个map里，由用户进入，就put进去，如下

private static final Map onlineUsers = new HashMap();

代码为

package com.socket;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpSession;
import javax.websocket.EndpointConfig;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;

import utils.MessageUtil;



@ServerEndpoint(value = /websocket,configurator=GetHttpSessionConfigurator.class)
public class ChatServlet {


    private static final Map onlineUsers = new HashMap();

    private static int onlineCount = 0;

    private HttpSession httpSession;

    private Session session;


    @OnOpen
    public void onOpen(Session session,EndpointConfig config){

        this.session = session;
        this.httpSession = (HttpSession) config.getUserProperties().get(HttpSession.class.getName());
        if(httpSession.getAttribute(user) != null){
            onlineUsers.put(httpSession, this);
        }
        String names = getNames();
        String content = MessageUtil.sendContent(MessageUtil.USER,names);
        broadcastAll(content);
        addOnlineCount();           //在线数加1
        System.out.println(有新连接加入!当前在线人数为 + onlineUsers.size());
    }

    @OnClose
    public void onClose(){
        onlineUsers.remove(this);  //从set中删除
        subOnlineCount();           //在线数减1   
        System.out.println(有一连接关闭！当前在线人数为 + getOnlineCount());
    }

    @OnMessage
    public void onMessage(String message, Session session) throws IOException {

        HashMap messageMap = MessageUtil.getMessage(message);    //处理消息类
        String fromName = messageMap.get(fromName);    //消息来自人 的userId
        String toName = messageMap.get(toName);       //消息发往人的 userId
        String mapContent = messageMap.get(content);


        if(toName.isEmpty()){
            sendOffLine(fromName,toName);
            return;
        }

        if(all.equals(toName)){
            String msgContentString = fromName + 对所有人说:  + mapContent;   //构造发送的消息
            String content = MessageUtil.sendContent(MessageUtil.MESSAGE,msgContentString);
            broadcastAll(content);
        }else{
            try {
                String content = MessageUtil.sendContent(MessageUtil.MESSAGE,mapContent);
                singleChat(fromName,toName,content);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }


        System.out.println(来自客户端的消息: + message);
        broadcastAll(message);
    }

    private void singleChat(String fromName, String toName, String mapContent) throws IOException {
        String msgContentString = fromName + 对 + toName + 说:  + mapContent;
        String contentTemp = MessageUtil.sendContent(MessageUtil.MESSAGE,msgContentString);
        boolean isExit = false;
        for (HttpSession key : onlineUsers.keySet()) {
            if(key.getAttribute(user).equals(toName)){
                isExit = true;
            }
        }
        if(isExit){
            for (HttpSession key : onlineUsers.keySet()) {
                if(key.getAttribute(user).equals(fromName) || key.getAttribute(user).equals(toName)){
                    onlineUsers.get(key).session.getBasicRemote().sendText(contentTemp);
                }
            }
        }else{
            String content = MessageUtil.sendContent(MessageUtil.MESSAGE,客服不在线请留言...);
            broadcastAll(content);
        }

    }
    private void sendOffLine(String fromName, String toName) throws IOException {
        String msgContentString = toName + 不在线;
        String content = MessageUtil.sendContent(MessageUtil.MESSAGE,msgContentString);
        for (HttpSession key : onlineUsers.keySet()) {
            if(key.getAttribute(user).equals(fromName) || key.getAttribute(user).equals(toName)){
                onlineUsers.get(key).session.getBasicRemote().sendText(content);
            }
        }
    }
    private static void broadcastAll(String msg) {
        for (HttpSession key : onlineUsers.keySet()) {
            try {
                onlineUsers.get(key).session.getBasicRemote().sendText(msg);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    @OnError
    public void onError(Session session, Throwable error){
        System.out.println(发生错误);
        error.printStackTrace();
    }


    private String getNames() {
        String names = ;
        for (HttpSession key : onlineUsers.keySet()) {
            String name = (String) key.getAttribute(user);
            names += name + ,;
        }
        String namesTemp = names.substring(0,names.length()-1);
        return namesTemp;
    }

    public static synchronized int getOnlineCount() {
        return onlineCount;
    }

    public static synchronized void addOnlineCount() {
        ChatServlet.onlineCount++;
    }

    public static synchronized void subOnlineCount() {
        ChatServlet.onlineCount--;
    }

}

前台的页面没有改变，经测试，可行！！！