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标题: 关于AJAX： [打印本页]

作者: 成吉思汗 时间: 2012-4-22 22:08
标题: 关于AJAX：
使用AJAX异步通信时，客户端总是接收不到服务器端返回的信息。这个怎么加速器呢？求解。
谢谢！

作者: 张卯 时间: 2012-4-22 22:34
高手啊，我们还在混基础，你都开始搞AJAX了~

作者: 李震李震李震 时间: 2012-4-23 03:45
你可以贴代码，不然的话这么一问我们也不知道情况的。

作者: liumeng 时间: 2012-4-23 14:18
贴出来源码不然谁知道啊

作者: 成吉思汗 时间: 2012-4-23 17:06
JavaScript代码:
// 浏览器对象
var xmlHttp = null;

/**
* 创建浏览器对象
*/
function getXmlHttpRequest() {
try {
// Internet Explorer
xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
// 微软的IE浏览器
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) {
try {
// Firefox,Poera 8.0+,Safari
xmlHttp = new XMLHttpRequest();
} catch (e) {
alert("您的浏览器不支持AJAX");
return false;
}
}
}
}

function checkUserExists() {
// 获取浏览器对象
getXmlHttpRequest();

var userName = document.getElementById("name");
if (userName.value == "") {
// document.getElementById("nameInfo").innerHTML = "用户名不能为空!";
alert("用户名不能为空");
return false;
}

// 设置连接地址
var url = "MessageServlet.RegisterServlet?userName=" + userName.value
+ "&type=checkName";

if (xmlHttp != null) {

// 设置回调函数
xmlHttp.onreadystatechange = stateChanged;

// 打开与服务器响应的地址连接
xmlHttp.open("get", url);

// 发送请求
xmlHttp.send(null);

}
return true;
}

function stateChanged() {
if (xmlHttp.readyState == 4) {
if (xmlHttp.status == 200) {
document.getElementById("nameInfo").innerHTML = xmlHttp.responseText;
// alert(xmlHttp.responseText);

}
}
}

/**
* 通用函数
*
* @param {Object}
* element ID名称
* @return {TypeName} 对象
*/
function $(element) {
return document.getElementById(element);
}

/**
* 验证用户名是否为空
*
* @return {TypeName}
*/
function checkName() {
var name = $("name");
var nameInfo = $("nameInfo");
if (name.value == "")
return false;
}

/**
* 当密码文本框获取光标时
*/
function pwdOnfocus() {
var pwdInfo = $("pwdInfo");
pwdInfo.innerHTML = "密码由大小写英文字母/数字组成，<br />长度为6-20位";
}

/**
* 当密码文本框失去光标时
*
* @return {TypeName}
*/
function checkPwd() {
var pwd = $("pwd");
var pwdInfo = $("pwdInfo");
var reg = /^([a-zA-Z0-9]){6}$/;
if (pwd.value == "") {
pwdInfo.innerHTML = "密码不能为空!";
} else {
pwdInfo.innerHTML = reg.test(pwd.value) ? "密码格式输入正确" : "密码格式输入错误";
}
return reg.test(pwd.value) ? true : false;
}

/**
* 验证重复密码是否为空和与密码是否一致
*/
function checkRepwd() {
var pwd = $("pwd");
var rePwd = $("repwd");
var rePwdInfo = $("rePwdInfo");
if (rePwd.value == "") {
rePwdInfo.innerHTML = "确认密码不能为空";
} else {
rePwdInfo.innerHTML = pwd.value == rePwd.value ? "确认密码通过"
: "两次密码输入不一致，<br />请重新输入";
}
return pwd.value == rePwd.value ? true : false;
}

/**
* 当Email文本框获取光标时
*/
function emailOnfocus() {
var emailInfo = $("emailInfo");
emailInfo.innerHTML = "XXX@XXX.XXX";
}

/**
* 当Email文本框失去光标时
*
* @return {TypeName}
*/
function checkEmail() {
var email = $("email");
var emailInfo = $("emailInfo");
var reg = /^\w+@\w+(\.[a-zA-Z]{2,3}){1,2}$/;
if (email.value == "") {
emailInfo.innerHTML = "email地址不能为空";
} else {

emailInfo.innerHTML = reg.test(email.value) ? "email输入正确!"
: "email格式输入错误!";
}
return reg.test(email.value) ? true : false;
}

/**
* 验证全部信息
*/
function checkAll() {
var nameInfo = $("nameInfo");
if (nameInfo.innerHTML == "该用户已存在!") {
alert("该用户已注册");
return false;
}
var flag = checkUserExists() && checkPwd() && checkRepwd() && checkEmail() ? true
: false;

return flag;
}

/**
*
*/
function register() {
getXmlHttpRequest();
var name = document.getElementById("name");
var pwd = document.getElementById("pwd");
var email = document.getElementById("email");

// 设置回调函数
xmlHttp.onreadystatechange = aaa;
xmlHttp.open("get", "register.RegisterServlet?type=register&name="
+ name.value + "&pwd=" + pwd.value + "&email=" + email.value, true);

xmlHttp.send(null);
}

function aaa() {

if (xmlHttp.readyState == 4) {
if (xmlHttp.status == 200) {
alert(xmlHttp.responseText);// 就这一步出不来
}
}
}

function resetInfo() {
$("nameInfo").innerHTML = "";
$("pwdInfo").innerHTML = "";
$("rePwdInfo").innerHTML = "";
$("emailInfo").innerHTML = "";
}

作者: 成吉思汗 时间: 2012-4-23 17:07
JSP代码:
<%@ page language="java" import="java.util.*"
contentType="text/html; charset=gbk" pageEncoding="gbk"%>
<%
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>注册页面</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="CSS/register.css">

<script type="text/javascript" src="js/register.js">
</script>

</head>

<body>
<div id="register">
<div id="title"></div>
<div id="body">
<form id="myFormRegister" name="myFormRegister" method="post"
action="javascript:register()" onsubmit="return checkAll()">

<table>
<tr>
<td>
<label for="name">
  用户名: 
</label>
</td>
<td>
<input type="text" id="name" name="name" class="texts"
onblur="checkUserExists()" />
</td>
<td>
<span id="nameInfo"></span>
</td>
</tr>

<tr>
<td>
<label for="pwd">
  密  码: 
</label>
</td>
<td>
<input type="password" id="pwd" name="pwd" class="texts"
onfocus="pwdOnfocus()" onblur="checkPwd()" />
</td>
<td>
<span id="pwdInfo"></span>
</td>
</tr>

<tr>
<td>
<label for="rePwd">
确认密码: 
</label>
</td>
<td>
<input type="password" id="rePwd" name="rePwd" class="texts"
onblur="checkRepwd()" />
</td>
<td>
<span id="rePwdInfo"></span>
</td>
</tr>

<tr>
<td>
<label for="email">
  邮  箱: 
</label>
</td>
<td>
<input type="text" id="email" name="email" class="texts"
onfocus="emailOnfocus()" onblur="checkEmail()" />
</td>
<td>
<span id="emailInfo"></span>
</td>
</tr>

</table>
<p>
<input type="submit" id="reg" name="reg" value="" />
  
<input type="reset" id="reset" name="reset" value=""
onclick="resetInfo()" />
</p>
<p>
<a href="index.jsp"><img src="images/sms_btn_goback.png" /> </a>
</p>
</form>
</div>
</div>
</body>
</html>
Servlet代码:
package com.control;

import java.io.IOException;
import java.io.PrintWriter;

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

import com.biz.UserDaoImpl;
import com.model.entity.User;

@SuppressWarnings("serial")
public class RegisterServlet extends HttpServlet {

/**
   * Constructor of the object.
   */
public RegisterServlet() {
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 {

doPost(request, response);
}

/**
   * 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 {

// 设置输入文本为中文
request.setCharacterEncoding("gbk");
// 设置输出文本为中文
response.setCharacterEncoding("gbk");
response.setContentType("text/html; charset=gbk");

PrintWriter out = response.getWriter();

String type = request.getParameter("type");

System.out.println(type);

// 实例化用户对象
User user = new User();

if (type.equals("checkName")) {

// 获取用户名
String name = request.getParameter("userName");

user.setUserName(name);
int result = new UserDaoImpl().getUserCount(user);
System.out.println("this is line 93:>>>>");
if (result == 0) {
out.print("用户名合法!");
} else {
out.print("该用户已存在!");
}

} else if ("register".equals(type)) {
String name = request.getParameter("name");
String pwd = request.getParameter("pwd");
String email = request.getParameter("email");

user.setUserName(name);
user.setPassword(pwd);
user.setEmail(email);

int result = new UserDaoImpl().addUser(user);

if (result == 1) {
out.print("恭喜你!注册成功!");// 就这句话无法获取

request.getRequestDispatcher("index.jsp").forward(request,
response);

} else {
out.print("很抱歉,注册失败!");
}
}

}

/**
   * Initialization of the servlet. <br>
   *
   * @throws ServletException
   *          if an error occurs
   */
public void init() throws ServletException {
// Put your code here
}

}

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