Solve the 'no permission' error in cross-domain access in AJAX_javascript skills

Access to non-same domain websites is prohibited. Here is an example to access http://www.google.cn,




Save this code to test.html, directly locally There is no problem opening it with IE, but after uploading the code to the server, a problem occurs - JS prompts a "no permission" error!!! How to solve this?
Think about it below: Since you can’t access non-same-domain addresses, you can only access addresses in the same domain. How do you get the content of non-same-domain web pages from dynamic files in the same domain? We still think of AJAX, but this AJAX is executed on the server side.
The general idea is this: first submit the URL to the file in your own site using AJAX, such as getPage.asp---pass it again in getPage.asp The server XMLHTTP accesses the submitted URL---returns the obtained content to the page where the URL was submitted--displays the content
Let’s start organizing the code, starting with the test.html file




Then there is the getpage.asp file (note: this file must be saved in UTF-8 format to prevent garbled characters), as follows:

response.charset=" UTF-8"
reg="
/]*). /{0,1}>"
'Function name: GetResStr
'Function: Get the HTML code of the specified URL
' Parameters: URL - the URL to be obtained
function GetResStr(URL)
err.clear
dim ResBody,ResStr,PageCode,ReturnStr
Set Http=createobject("MiCROSOFT.XMLHTTP")
Http.open "GET",URL,False
Http.Send()
If Http.Readystate =4 Then
If Http.status=200 Then
ResStr=http.responseText
ResBody =http.responseBody
PageCode=GetCode(ResStr,reg)
ReturnStr=BytesToBstr(http.responseBody,PageCode)
GetResStr=ReturnStr
End If
End If
End Function

'Function name: BytesToBstr
'Function: Convert binary data to characters
'Parameters: Body-binary data, Cset-text encoding method
Function BytesToBstr(Body,Cset)
Dim Objstream
Set Objstream = CreateObject("adodb.stream")
objstream.Type = 1
objstream.Mode =3
objstream.Open
objstream.Write body
objstream. Position = 0
objstream.Type = 2
objstream.Charset =Cset
BytesToBstr = objstream.ReadText
objstream.Close
set objstream = nothing
End Function

'Function name: GetCode
'Function: Convert binary to character
'Parameters: str-string to be queried, regstr-regular expression
Function GetCode(str,regstr)
Dim Reg, serStr
set Reg= new RegExp
Reg.IgnoreCase = True
Reg.MultiLine = True
Reg.Pattern =regstr
if Reg.test(str) then 'If a match is found
Set Cols = Reg.Execute(str)
serStr=Cols(0).SubMatches(0) 'Use the first matched item
else 'Otherwise give the default value gb2312, which is a bit economical Lazy method, if the page does not give the encoding format, it is really troublesome to know
serStr="gb2312"
end if
GetCode=serStr
end function

dim url:url =request.querystring("url")
response.write GetResStr(URL)
%>

The code is organized. After the experiment, the content of http://www.google.cn was successfully extracted. !!!!This can solve the "no permissions" problem.
Actually, a simple getpage.asp can be obtained, but it cannot dynamically process the DOM like js. There is another problem. If you use the first method to access http://www.baidu.com, garbled characters will appear, because baidu encoding is GB2312, and XMLHTTP returns UTF-8 encoding format. Using the second method, such a problem will not occur. As long as the site that defines the encoding format can return information normally (this does not include some sites that use special encoding).