AJAX 学习笔记[三] get 与post 模式的区别

如果是get 模式的请求,则将传递参数通过URL 地址发送到服务器端;

如果是post 模式的请求,则将传递参数通过send( ) 方法发送到服务器端(并且必须设置请求文件头);

post 模式的代码如下:

<script type="text/javascript">
<!--
var queryString = "firstName=xugang&birthday=1227";
var url = "9-3.aspx?timetamp=" + new Date().getTime();
xmlHttp.open("POST",url);
xmlHttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
xmlHttp.send(queryString); //该语句负责发送数据
//-->
</script>

一个演示get 模式post 模式区别的示例:

客户端(9-3.html)

代码示例:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<title>GET VS. POST</title>
<script language="javascript">
var xmlHttp;
function createXMLHttpRequest(){
if(window.ActiveXObject)
xmlHttp = new ActiveXObject("Microsoft.XMLHttp");
else if(window.XMLHttpRequest)
xmlHttp = new XMLHttpRequest();
}
function createQueryString(){
var firstName = document.getElementById("firstName").value;
var birthday = document.getElementById("birthday").value;
var queryString = "firstName=" + firstName + "&birthday=" + birthday;
return encodeURI(encodeURI(queryString)); //两次编码解决中文乱码问题
}
// GET 模式
function doRequestUsingGET(){
createXMLHttpRequest();
var queryString = "9-3.aspx?";
queryString += createQueryString() + "&timestamp=" + new Date().getTime();
xmlHttp.onreadystatechange = handleStateChange;
xmlHttp.open("GET",queryString);
xmlHttp.send(null);
}
// POST 模式
function doRequestUsingPOST(){
createXMLHttpRequest();
var url = "9-3.aspx?timestamp=" + new Date().getTime();
var queryString = createQueryString();
xmlHttp.open("POST",url);
xmlHttp.onreadystatechange = handleStateChange;
xmlHttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
xmlHttp.send(queryString);
}
function handleStateChange(){
if(xmlHttp.readyState == 4 && xmlHttp.status == 200){
var responseDiv = document.getElementById("serverResponse");
responseDiv.innerHTML = decodeURI(xmlHttp.responseText); //解码
}
}
</script>
</head>
<body>
<h2>输入姓名和生日</h2>
<form>
<input type="text" id="firstName" /><br>
<input type="text" id="birthday" />
</form>
<form>
<input type="button" value="GET" onclick="doRequestUsingGET();" /><br>
<input type="button" value="POST" onclick="doRequestUsingPOST();" />
</form>
<div id="serverResponse"></div>
</body>
</html>

服务器端(9-3.aspx)

代码示例:

<%@ Page Language="C#" ContentType="text/html" ResponseEncoding="gb2312" %>
<%@ Import Namespace="System.Data" %>
<%
if(Request.HttpMethod == "POST")
Response.Write("POST: " + Request["firstName"] + ", your birthday is " + Request["birthday"]);
else if(Request.HttpMethod == "GET")
Response.Write("GET: " + Request["firstName"] + ", your birthday is " + Request["birthday"]);
%>

通常在数据不多,并且不敏感的时候,使用get 模式的请求;

而数据量大,或者数据敏感的时候,使用post 模式的请求。




本文转自钢钢博客园博客,原文链接:http://www.cnblogs.com/xugang/archive/2010/08/07/1794753.html,如需转载请自行联系原作者

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