Simple example analysis based on XMLHTTP in web (figure)

Web|xml
　　 Introduction
　　
We all know that you can get the data from form forms by post or gets, so how do we get the data out of the page without refreshing the submission? This is going to be through the XMLHTTP agreement. XMLHTTP is part of the XMLDOM technology.
　　
The following code is a very simple example, we use XMLHTTP technology to achieve a simple user login.
　　
　　 Start
　　
1. Simple login Page
　　
login.jsp
function Toserver () {
var xml = "<root>" +
"<name>" +document.all (' name '). value+ "</name>" +
"<pwd>" +document.all (' pwd '). value+ "</pwd>" +
"</root>";
　　
var xmlsender = new ActiveXObject ("Microsoft.XMLHTTP");
Xmlsender.open ("POST", ' do_login.jsp ', false);
Xmlsender.send ((XML));
alert (Xmlsender.responsetext); Can handle the results returned by the background
}
　　
Name: <input type= "text" id= "name"/><br>
Password: <input type= "text" id= "pwd"/><br>
<input type= "button" value= "Login" >
　　
2. Background of the Login processing page
do_login.jsp
　　
<%
Read XMLHTTP Stream
Java.io.BufferedReader br = Request.getreader ();
String str = "";
while (str!= null) {
str = Br.readline ();
Process (str); Parsing XML can be implemented in any language for business processing
}
　　
return information
Javax.servlet.ServletOutputStream SOS = Response.getoutputstream ();
Sos.print ("Login Success");
Sos.close ();
%>
　　
3. The results are as follows:
　　
　　 Summary
　　
With the traditional "submit-postback-redraw" type of web system basic operating structure is different, we can through XMLHTTP to achieve without a refreshing client directly with the server interaction, greatly improve the user's feelings.
　　
　　 reference materials
　　
xmlHTTP Method:
　　
Open Bstrmethod, bstrURL, Varasync, Bstruser, Bstrpassword
Bstrmethod: Data transfer mode, i.e. get or post.
bstrURL: URL of the Service Web page.
Varasync: Whether to execute synchronously. The default is true, which is synchronous execution, but can only be implemented synchronously in the DOM.
It is generally set to false in the application, that is, asynchronous execution.
Bstruser: User name, can be omitted.
Bstrpassword: User password, can be omitted.
　　
Send Varbody
Varbody: Instruction set. can be XML format data, or it can be a string, a stream, or an unsigned integer array. You can also omit the instruction by substituting the URL parameter for the open method.
　　
setRequestHeader Bstrheader, Bstrvalue
Bstrheader:http Header (header)
Value of Bstrvalue:http header (header)
If the open method is defined as post, you can define a form to upload:
Xmlhttp.setrequestheader "Content-type", "application/x-www-form-urlencoded"
　　
XMLHTTP Properties:
　　
onReadyStateChange: Gets the event handle that returns the result in the synchronous execution mode. Can only be invoked in the DOM.
Responsebody: The result returns an array of unsigned integers.
Responsestream: The result is returned as a IStream stream.
ResponseText: The result is returned as a string.
Responsexml: Results are returned as XML format data.