Converting Chinese Characters from UTF-8 to GB2312

Question

Hi,
I need to interact with an external system that only accepts GB2312 encoded strings as input.
I have a site that is used to capture user input before feeding the data to the system. (Refer to the following)
<%
String strName = request.getParameter("strName");
boolean serviceStatus = false;
if (request.getParameter("strName") != null)
serviceStatus=invokeTheService(strName,"text_process");
%>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
How can i encode the "strName" variable value to "GB2312". (Do be informed that i am unable to change the meta Content-Type to GB2312)
I had tried using the following but was unable get it right.
strName = new String(strName.getBytes("UTF-8"),"GB2312");
I had also tried using the CharsetEncoder.encode to attempt to encode it to GB2312 but kept getting a UnmappableCharacterException message.
*Correct me if i'm wrong, but UTF-8 tends to represent characters in 1,2 or 3 bytes.
In the case of chinese characters, each character is represented by 3 bytes.
GB2312 tends to represent each character in 2 bytes.
So if i have a 3 chinese character as input, the original strName.length() would return 9. whereas the Gb2312 encoded strName should return 6 ?

Answer 1

KeithTan wrote:
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
How can i encode the "strName" variable value to "GB2312". (Do be informed that i am unable to change the meta Content-Type to GB2312)Then what is the point of converting to GB2312 if you inform the recipient that it is encoded as something other than GB2312?
>
I had tried using the following but was unable get it right.
strName = new String(strName.getBytes("UTF-8"),"GB2312");That can never ever be right. Java Strings are UNICODE encoded as UTF16. They are always encoded internally as UTF16 so your code says - convert the string to UTF8 bytes and then, even though they are UTF8 bytes and not GB2312 bytes, treat them as GB2312 bytes. That will almost certainly corrupt the String
>
I had also tried using the CharsetEncoder.encode to attempt to encode it to GB2312 but kept getting a UnmappableCharacterException message.Even if Java does support GB2312 then it is a wast of time sending GB2312 content to a client and telling the client that it is UTF-8 .