ruanchengui1
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思想斗争了很久，终于开始接触ajax，作为一个初学者，模仿是个不错的学习方法，至少我是这么学过来的，站长巨人的肩膀上。
这次模仿的内容来自《基于J2EE的Ajax宝典》电子书，在此表示感谢。介绍的是Jsp页面聊天器和ajax聊前器的区别，及ajax的特点体现。
---相对于传统的JSP聊天室而言，Ajax聊天室的速度更快，响应更加流畅。对于复杂页面，Ajax的优势将更加明显：Ajax聊天室只需从服务器获取必须更新的聊天记录，而无须下载整个页面。
Ajax聊天室的最大特点是页面无须刷新，用户感觉不到页面的下载。使用Ajax聊天室时，用户感觉到仿佛在使用普通的Socket聊天室，因为聊天室的页面无须刷新，但用户的聊天信息实时更新。这一切都依赖于Ajax的异步发送请求和动态更新页面。
学习能力自称很强的我，在这下才知道是多么的渺小啊，花了整整一天的时间才得以实现，但这个过程虽败犹荣啊，更深刻的了解了ajax功能实现的整个流程。
1：创建XMLHttpRequest对象
2：取得与服务器的连接（用到post请求）
3：发送post请求时应该增加该文件头
4：指定当XMLHttpRequest状态变化时的处理函数（一个监听的过程）
5:发送请求，及发送信息
-1：这里就是步骤4中的处理函数的书写了
下面贴出ajax聊天器的代码（无数据库）
聊天器聊天界面代码：
有三个控制类处理类（servlet）
1：注册控制处理
2：登陆控制处理类：
3：聊天控制处理类：
然后就是web.xml的配置了
最后就是业务处理了：
至此ajax聊天器的程序测试就这样完成了。
这次模仿的内容来自《基于J2EE的Ajax宝典》电子书，在此表示感谢。介绍的是Jsp页面聊天器和ajax聊前器的区别，及ajax的特点体现。
---相对于传统的JSP聊天室而言，Ajax聊天室的速度更快，响应更加流畅。对于复杂页面，Ajax的优势将更加明显：Ajax聊天室只需从服务器获取必须更新的聊天记录，而无须下载整个页面。
Ajax聊天室的最大特点是页面无须刷新，用户感觉不到页面的下载。使用Ajax聊天室时，用户感觉到仿佛在使用普通的Socket聊天室，因为聊天室的页面无须刷新，但用户的聊天信息实时更新。这一切都依赖于Ajax的异步发送请求和动态更新页面。
学习能力自称很强的我，在这下才知道是多么的渺小啊，花了整整一天的时间才得以实现，但这个过程虽败犹荣啊，更深刻的了解了ajax功能实现的整个流程。
1：创建XMLHttpRequest对象
2：取得与服务器的连接（用到post请求）
3：发送post请求时应该增加该文件头
4：指定当XMLHttpRequest状态变化时的处理函数（一个监听的过程）
5:发送请求，及发送信息
-1：这里就是步骤4中的处理函数的书写了
下面贴出ajax聊天器的代码（无数据库）
聊天器聊天界面代码：
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'chat2.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<script type="text/javascript">
var input;
var XMLHttpReq;
function createXMLHttpRequest()
{
input=document.getElementById("123");
input.focus();
XMLHttpReq = new ActiveXObject("Msxml2.XMLHTTP");
var chatMsg=input.value;
var url = "Chat.do";
XMLHttpReq.open("post", url, true);
XMLHttpReq.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
XMLHttpReq.onreadystatechange = processResponse;
//发送请求后，将聊天信息的输入文本框清空
input.value="";
//发送请求，send的参数包含许多的key-value对
//即以“请求参数名=请求参数值”的形式发送请求参数
XMLHttpReq.send("chatMsg=" + chatMsg); // 发送请求
}
function sendEmptyRequest()
{
//创建XMLHttpRequest对象
if(window.XMLHttpRequest)
{
XMLHttpReq=new XMLHttpRequest();
}
if (window.ActiveXObject)
{
try
{
//使用AcitveXObject函数创建浏览器
XMLHttpReq = new ActiveXObject("Msxml2.XMLHTTP");
}
catch (e)
{
//如果出现异常，再次尝试以如下方式创建XMLHttpRequest对象
try
{
XMLHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
}
catch (e)
{
window.alert("internet");
}
}
}
//定义服务器响应的URL
var url = "Chat.do";
//建立与服务器的连接
XMLHttpReq.open("post", url, true);
//设置发送请求的参数格式
XMLHttpReq.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
//指定响应处理函数
XMLHttpReq.onreadystatechange = processResponse;
//发送请求
XMLHttpReq.send(null);
setTimeout("sendEmptyRequest()", 800);
}
function processResponse()
{
//如果服务器响应已经完成
if(XMLHttpReq.readyState == 4)
{
//判断对象状态，如果服务器生成了正常响应
if (XMLHttpReq.status == 200)
{
//信息已经成功返回，开始处理信息
//将聊天文本域的内容设置成聊天信息
document.getElementById("chatArea").value = XMLHttpReq.responseText;
}
else
{
//页面不正常
window.alert("您所请求的页面有异常。");
}
}
}
function enterHandler(event)
{
//定义键盘中发出事件的键
var keyCode=event.keyCode?event.keyCode:event.which?event.which:
event.charCode;//回车键的代码为13，如果按下了回车键
if (keyCode == 13)
{
createXMLHttpRequest();
}
}
</script>
</head >
<body onload="JavaScript:sendEmptyRequest();">
<input type="button" onclick="JavaScript:createXMLHttpRequest();" value="clickme">
<table width="780" border="1" align="center">
<tr>
<td><p align="center">聊天页面</p>
<!-- 下面定义聊天使用的文本域，该文本域用于显示当前聊天信息 -->
<p align="center">
<textarea id="chatArea" name="chatArea" cols="100" rows="30" readonly="readonly"></textarea>
</p>
<div align="center">
<!-- 下面是输入聊天信息所使用的文本，并为onKeyPress事件指定了监听函数 -->
<input id="123" name="chatMsg" type="text" size="90" onKeyPress="JavaScript:enterHandler(event);">
<!-- 下面是输入聊天信息的文本框，并为onclick事件指定了监听函数 -->
<input type="button" name="button" value="提交" onclick="JavaScript:createXMLHttpRequest();">
</div>
<p> </p>
</td>
</tr>
</table>
</body>
</html>
有三个控制类处理类（servlet）
1：注册控制处理
package com.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.method.ChatService;
public class RegServlet extends HttpServlet {
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String name=request.getParameter("username");
String pass=request.getParameter("password");
if(name==null||pass==null)
{
request.setAttribute("tip", "用户名和密码都不能为空");
forward("/reg.jsp", request, response);
}
//开始调用业务逻辑对象的方法
try
{
//调用业务逻辑对象的方法
if (ChatService.instance().addUser(name, pass))
{
//如果注册成功，则将提示信息存入系统的tip属性
request.setAttribute("tip", "注册成功，请登录系统");
//将请求转发到reg.jsp页面显示
forward("/reg.jsp", request, response);
}
else
{
//如果不能正常注册，则将提示信息放入request属性
request.setAttribute("tip", "无法正常注册，请重试");
forward("/reg.jsp", request, response);
}
}
//如果捕捉到异常，例如注册的用户名已经存在
catch (Exception e)
{
//将异常信息设置成request属性
request.setAttribute("tip", e.getMessage());
forward("/reg.jsp", request, response);
}
}
private void forward(String url, HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException
{
ServletContext sc = getServletConfig().getServletContext();
RequestDispatcher rd = sc.getRequestDispatcher(url);
rd.forward(request, response);
}
/**
* Constructor of the object.
*/
public RegServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print(" This is ");
out.print(this.getClass());
out.println(", using the GET method");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print(" This is ");
out.print(this.getClass());
out.println(", using the POST method");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}
2：登陆控制处理类：
package com.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import com.method.ChatService;
public class LoginServlet extends HttpServlet {
/**
* Constructor of the object.
*/
public LoginServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print(" This is ");
out.print(this.getClass());
out.println(", using the GET method");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print(" This is ");
out.print(this.getClass());
out.println(", using the POST method");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String name=request.getParameter("username");
String pass=request.getParameter("password");
if(ChatService.instance().validLogin(name, pass))
{ request.getSession().setAttribute("username", name);
String message=ChatService.instance().getMsg();
request.setAttribute("message", message);
forward("/chat2.jsp",request,response);
}
else
{
request.setAttribute("tip", "用户名和密码不匹配");
forward("/login.jsp",request,response);
}
}
private void forward(String url, HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException
{
ServletContext sc = getServletConfig().getServletContext();
RequestDispatcher rd = sc.getRequestDispatcher(url);
rd.forward(request, response);
}
}
3：聊天控制处理类：
package com.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.method.ChatService;
public class ChatServlet extends HttpServlet {
/**
* Constructor of the object.
*/
public ChatServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print(" This is ");
out.print(this.getClass());
out.println(", using the GET method");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=gbk");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print(" This is ");
out.print(this.getClass());
out.println(", using the GET method");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
String msg=request.getParameter("chatMsg");
String user=(String) request.getSession().getAttribute("username");
if(msg!=null)
{
ChatService.instance().addMsg(user, msg);
}
// String message=ChatService.instance().getMsg();
// request.setAttribute("message", message);
// forward("/chat.jsp",request,response);
//设置中文输出流
response.setContentType("text/html;charset=utf-8");
//获取页面输出流
PrintWriter out = response.getWriter();
//将当前系统的聊天记录输出到页面
out.println(ChatService.instance().getMsg());
}
private void forward(String url, HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException
{
ServletContext sc = getServletConfig().getServletContext();
RequestDispatcher rd = sc.getRequestDispatcher(url);
rd.forward(request, response);
}
}
然后就是web.xml的配置了
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>RegServlet</servlet-name>
<servlet-class>com.servlet.RegServlet</servlet-class>
</servlet>
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>ChatServlet</servlet-name>
<servlet-class>com.servlet.ChatServlet</servlet-class>
</servlet>
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>com.servlet.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>RegServlet</servlet-name>
<url-pattern>/Reg.do</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>ChatServlet</servlet-name>
<url-pattern>/Chat.do</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/Login.do</url-pattern>
</servlet-mapping>
</web-app>
最后就是业务处理了：
package com.method;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.LinkedList;
import java.util.Properties;
public class ChatService {
private static ChatService cs;
private Properties userList;
private LinkedList<String> chatMsg;
private ChatService()
{}
public static ChatService instance()
{
if(cs==null)
{
cs=new ChatService();
}
return cs;
}
public boolean validLogin(String user,String pass)throws IOException
{
if(loadUser().getProperty(user)==null)
{
return false;
}
if(loadUser().getProperty(user).equals(pass))
{
return true;
}
return false;
}
public boolean addUser(String name,String pass)throws Exception
{
if(userList==null)
{
userList=loadUser();
}
if(userList.containsKey(name))
{
throw new Exception("用户名已经存在，请重新选择用户名");
}
userList.setProperty(name,pass);
saveUserList();
return true;
}
public String getMsg()
{
if(chatMsg==null)
{
chatMsg=new LinkedList<String>();
return "";
}
String result="";
for(String tmp:chatMsg)
{
result+=tmp+"\n";
}
return result;
}
public void addMsg(String user,String msg)
{
if(chatMsg==null)
{
chatMsg=new LinkedList<String>();
}
if(chatMsg.size()>40)
{
chatMsg.removeFirst();
}
chatMsg.add(user+"说："+msg);
}
private Properties loadUser()throws IOException
{
if(userList==null)
{
File f=new File("userFile.properties");
if(!f.exists())
f.createNewFile();
userList=new Properties();
userList.load(new FileInputStream(f));
}
return userList;
}
private boolean saveUserList()throws IOException
{
if(userList==null)
{
return false;
}
userList.store(new FileOutputStream("userFile.properties"), "userList");
return true;
}
}
至此ajax聊天器的程序测试就这样完成了。
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学习-学习平台-学习平台源码-学习平台java代码-学习平台设计与实现-基于springboot的学习平台-基于Web的学习平台设计与实现-学习网站-学习网站源码-学习网站java代码-学习项目-学习项目代码-学习系统-学习系统源码-...
Ajax分页组件--web-java,美观通用
积分多的大佬打赏下，缺积分用；积分不够得移步https://www.cnblogs.com/BambooLamp/p/12603299.html 原文：https://segmentfault.com/a/1190000012469713
ajax课件--------Ajax.ppt,绝对经典，放心下载！
Ajax-Online-java-compiler.zip,在线Java编译器,ajax代表异步javascript和xml。它是多种web技术的集合，包括html、css、json、xml和javascript。它用于创建动态网页，其中网页的小部分在不重新加载网页的情况下更改...
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Ajax-magento2-ajax-layered-navigation.zip,ajax分层导航magento 2提供了一个过滤器列表，帮助您的客户以最短的方式搜索和获得他们最喜欢的产品。这个扩展应用了现代ajax技术来增强过滤系统，以提高用户对页面上每...
Ajax-magento2-ajax-cart-quick.zip,magento 2 ajax购物车扩展插件提供舒适的购物体验。客户可以很容易地选择可配置的选项并在弹出窗口中编辑项目，而不会浪费重新加载页面的时间。,ajax代表异步javascript和xml。它...
详细介绍了Ajax技术 简单的实例 让你快速精通Ajax技术
Ajax与Java高级程序设计
AJAX技术入门--详细介绍Ajax的机理和实现技术，包括Javascript语言、Xml、XMLHttpRequest对象等的介绍~~~
Ajax与Java高级程序设计
Ajax与Java高级程序设计
NULL 博文链接：https://lc2586.iteye.com/blog/725751