Dwr2实现聊天功能

利用的是一种默认的配置。

User和Message是2个Javabean，封装用户及消息数据。

ChatLogon负责登录后跳转到聊天页面。

Chat聊天的主类。

 

如下是具体代码：

User.java:

package com.dwr.chat.demo;

public class User {
	private String userId;
	private String area;

	public String getUserId() {
		return userId;
	}
	public void setUserId(String userId) {
		this.userId = userId;
	}
	public String getArea() {
		return area;
	}
	public void setArea(String area) {
		this.area = area;
	}
}

Message.java:

package com.dwr.chat.demo;

public class Message {
	private String from;
	private String to;
	private String msg;
	private String area;
	public String getFrom() {
		return from;
	}
	public void setFrom(String from) {
		this.from = from;
	}
	public String getTo() {
		return to;
	}
	public void setTo(String to) {
		this.to = to;
	}
	public String getMsg() {
		return msg;
	}
	public void setMsg(String msg) {
		this.msg = msg;
	}
	public String getArea() {
		return area;
	}
	public void setArea(String area) {
		this.area = area;
	}
	
	
}

ChatLogon.java:

package com.dwr.chat.demo;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Servlet implementation class ChatLogon
 */
public class ChatLogon extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public ChatLogon() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		this.doPost(request, response);
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String userId = request.getParameter("userId");
		String area = request.getParameter("area");
		if (userId == null || "".equals(userId) || area == null || "".equals(area)) {
			response.sendRedirect("/chat/jsp/logon.jsp");
		}
		else {
			HttpSession session = request.getSession();
			User user = new User();
			user.setArea(area);
			user.setUserId(userId);
			session.setAttribute("user", user);
			request.getRequestDispatcher("/chat/jsp/chat.jsp").forward(request, response);
		}
	}

}

Chat.java:

package com.dwr.chat.demo;

import java.util.Collection;

import javax.servlet.http.HttpSession;

import org.directwebremoting.ScriptBuffer;
import org.directwebremoting.ScriptSession;
import org.directwebremoting.WebContext;
import org.directwebremoting.WebContextFactory;

public class Chat {
	public void sendMsg(String msg, String to) {
		WebContext context = WebContextFactory.get();
		HttpSession session = context.getSession();
		ScriptSession ss = context.getScriptSession();
		Collection<ScriptSession> sess = context.getAllScriptSessions();
		System.out.println("sess length:" + sess.size());
		if (msg == null || "".equals(msg)) {
			return;
		}

		session.setAttribute("flag", session.hashCode());
		ss.setAttribute("flag", session.hashCode());
		User user = (User) session.getAttribute("user");
		if (ss.getAttribute("user") == null) {
			ss.setAttribute("user", user);
		}

		Message message = new Message();
		message.setFrom(user.getUserId());
		message.setMsg(msg);
		message.setTo("".equals(to) ? "所有人" : to);
		message.setArea(user.getArea());

		ScriptBuffer sbf = new ScriptBuffer();
		sbf.appendScript("Chat.recvMsg(");
		sbf.appendData(message);
		sbf.appendScript(");");
		
		// 是否有这个人
		boolean hasThisPerson = true;
		// 是否可以私聊
		boolean isPPOk = false;
		// 是否在同一区域。
		boolean isInSameArea = true;
		ScriptSession ssTo = null;
		// 是否是与自己聊天
		boolean isWithSlef = false;

		for (ScriptSession ssr : sess) {
			if (ssr != null) {
				User user2 = (User) ssr.getAttribute("user");
				if (user2 != null) {
					if ("".equals(to)) {
						// 发送信息给所有人。
						ssr.addScript(sbf);
						System.out.println("发送给所有人。");
					} else {
						if (user2.getArea().equals(user.getArea())) {
							if (user2.getUserId().equals(to)) {
								// 如果是自己，则不能进行私聊
								if (user2.getUserId().equals(user.getUserId())) {
									isWithSlef = true;
									break;
								}
								else {
									ssTo = ssr; // 私聊
									isPPOk = true;
									break;
								}
							} else { // 没有这个人呢。
								hasThisPerson = false;
								break;
							}
						} else {
							isInSameArea = false; // 用户与您不在同一区域
							break;
						}
					}
				}
			}
		}
		
		if (!hasThisPerson) {// 没有这个人。
			ss.addScript(new ScriptBuffer(// 不能return
			"alert('对不起，没有这个人！');"));
			System.out.println("对不起，没有这个人！");
		}
		
		if (!isInSameArea) {
			ss.addScript(new ScriptBuffer("alert('" + to
					+ "与您不在同一区域！');"));
			System.out.println("不再同一个区域。。。");
		}
		
		if (isPPOk) 
		{
			// 私聊
			ssTo.addScript(sbf);
			// 同时，发给自己
			ss.addScript(sbf);
			System.out.println("私聊。");			// 不能return
			ssTo = null;
		}
		
		if (isWithSlef) {
			ss.addScript(new ScriptBuffer("alert('自己不能跟自己聊天！');"));
			System.out.println("自己不能跟自己聊天。");// 不能return
		}
	}

	public void exitPage() {
		WebContext context = WebContextFactory.get();
		HttpSession ses = context.getSession();
		if (ses.getAttribute("flag") != null) {
			int flag = (Integer) ses.getAttribute("flag");
			Collection<ScriptSession> colls = context.getAllScriptSessions();

			for (ScriptSession ss : colls) {
				if (ss != null) {
					if ((Integer) ss.getAttribute("flag") == flag) {
						ss.invalidate();
						return;
					}
				}
			}
		}
	}
}

Chat.js:

var Chat = new function() {
	this.sendMsg = function(){
		var msg = document.getElementById("msg").value;
		var pp = document.getElementById("pps");

		if (pp.checked) {
			// 如果选中复选框，说明是私聊。
			pp = document.getElementById("pp").value;			
		}
		else {
			pp = "";
		}
		if (msg !== "") {
			ChatServer.sendMsg(msg,pp);
			document.getElementById("msg").value = "";
		}
		else {
			alert("发送的消息不能为空！");
			return;
		}
	};
	this.recvMsg = function(data) {
		var dd = document.getElementById("msgCenter");
		if (data !== null) {
			var tr = document.createElement("tr");
			var td1 = document.createElement("td");
			var td2 = document.createElement("td");
			var td3 = document.createElement("td");
			var td4 = document.createElement("td");
			td1.innerText = dd.rows.length;
			td2.innerText = data.from;
			td3.innerText = data.to;
			td4.innerText = data.msg;
			tr.appendChild(td1);
			tr.appendChild(td2);
			tr.appendChild(td3);
			tr.appendChild(td4);
			dd.appendChild(tr);
		}
	};
	this.keySendMsg = function(e) {
		e = e || event;
		if (e.keyCode == 10) {
			sendMsg();
		}
	};
	
	// 在选中私聊复选框时，显示
	this.showOrHidePP = function(oItem) {
		var pp = document.getElementById("pp");
		if (oItem.checked) {
			pp.style.display =  "block";
		}	
		else {
			pp.style.display = "none";	
		}
	};
};

Login.jsp:

<%@ page language="java" contentType="text/html; charset=gb18030"
	pageEncoding="gb18030"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb18030">
<title>logon</title>
<link href="../css/global.css"></link>
</head>
<body>
	<fieldset style="width: 600px;">
		<legend>用户登录</legend>
		<form action="/dwr/chat/logon.action" method="post">
			<table width="500px" cellpadding="0" cellspacing="0">
				<tr>
					<td>用户ID：</td>
					<td><input type="text" name="userId">
					</td>
				</tr>
				<tr>
					<td>区域：</td>
					<td><input type="radio" name="area" value="etc01"
						checked="checked">电信一区 <input type="radio" name="area"
						value="etc02">电信二区</td>
				</tr>
				<tr align="center">
					<td colspan="2"><input type="submit" value="登录系统">
					</td>
				</tr>
			</table>
		</form>
	</fieldset>
</body>
</html>

chat.jsp:

<%@ page language="java" contentType="text/html; charset=gb18030"
	pageEncoding="gb18030"%>
<%@page import="com.dwr.chat.demo.User"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb18030">
<title>chat</title>
<link href="../css/global.css"></link>
<script type="text/javascript" src="/dwr/dwr/engine.js"></script>
<script type="text/javascript" src="/dwr/dwr/util.js"></script>
<script type="text/javascript" src="/dwr/dwr/interface/ChatServer.js"></script>
<script type="text/javascript" src="/dwr/chat/js/chat.js"></script>
<script type="text/javascript">
	window.onunload = ChatServer.exitPage();
	document.onunload = ChatServer.exitPage();
</script>
</head>
<body onload="dwr.engine.setActiveReverseAjax(true);ChatServer.sendMsg('','');">
<div>
	<%
		User user = (User)session.getAttribute("user");
	%>
	<span style="color:red;font-size:15px;">欢迎<%=user==null?"":user.getUserId() %></span>
</div>
	<div style="width:500px;">
		<fieldset>
			<legend>输入内容</legend>
			<input type="checkbox" id="pps" onclick="Chat.showOrHidePP(this);">私聊<input type="text" id="pp" style="display:none;">
			<table width="500px" cellpadding="0" cellspacing="0">
				<tr>
					<td>输入消息：</td>
					<td><textarea rows="8" cols="55" id="msg" name="msg"></textarea>
					</td>
				</tr>
				<tr align="center">
					<td colspan="2"><input type="button" value="发送" onclick="Chat.sendMsg();">
					</td>
				</tr>
			</table>
		</fieldset>
	</div>
	<div style="width:500px;">
		<fieldset>
			<legend>消息中心：</legend>
			<table width="500px" cellpadding="0" cellspacing="0" id="msgCenter" border="1">
				<tr>
					<td>编号</td>
					<td>发信人</td>
					<td>收信人</td>
					<td>消息内容</td>
				</tr>
			</table>
		</fieldset>
	</div>
</body>
</html>

web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>dwr</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <servlet-name>dwr-invoker</servlet-name>
    <servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>
    <init-param>
      <param-name>activeReverseAjaxEnabled</param-name>
      <param-value>true</param-value>
    </init-param>
    <init-param>
      <param-name>debug</param-name>
      <param-value>true</param-value>
    </init-param>
    <init-param>
             <param-name>crossDomainSessionSecurity</param-name>
             <param-value>false</param-value>
      </init-param>
      <init-param>
            <param-name>allowScriptTagRemoting</param-name>
            <param-value>true</param-value>
      </init-param>
    
  </servlet>
  <servlet-mapping>
  	<servlet-name>dwr-invoker</servlet-name>
  	<url-pattern>/dwr/*</url-pattern>
  </servlet-mapping>
  <servlet>
    <description></description>
    <display-name>ChatLogon</display-name>
    <servlet-name>ChatLogon</servlet-name>
    <servlet-class>com.dwr.chat.demo.ChatLogon</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>ChatLogon</servlet-name>
    <url-pattern>/chat/logon.action</url-pattern>
  </servlet-mapping>
</web-app>

dwr.xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN"
 "http://www.getahead.ltd.uk/dwr/dwr20.dtd">

<dwr>
	<allow>
		<create creator="new" javascript="ChatServer">
			<param name="class" value="com.dwr.chat.demo.Chat"></param>
		</create>
		<convert converter="bean" match="com.dwr.chat.demo.User"></convert>
		<convert converter="bean" match="com.dwr.chat.demo.Message"></convert>
	</allow>
</dwr>