Java Strings as non-Unicode Encoded Byte Sequences

JSP Tutorials - Herong's Tutorial Examples

∟Non-ASCII Characters Support in JSP Pages

∟Java Strings as non-Unicode Encoded Byte Sequences

This section provides a tutorial example on how to use Java String data type to enter non-ASCII character as byte sequences encoded with a local language encoding schema.

Let's try option 1 mentioned in the previous section first, which uses Java strings to enter non-ASCII characters as byte sequences encoded with a local language encoding schema. Here is my sample JSP page, HelpGB2312Java.jspx:

<?xml version="1.0"?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" version="2.3">
<!-- HelpGB2312Java.jspx
 - Copyright (c) 2006 HerongYang.com. All Rights Reserved.
-->
<jsp:directive.page contentType="text/html; charset=gb2312"/>
<jsp:declaration><![CDATA[
   private java.io.OutputStream outStream;
   private void writeGB(String s) throws Throwable {
      for (int i=0; i<s.length(); i++) {
         char c = s.charAt(i);
         byte b = (byte) (c>>8 & 0x00FF);
         if (b!=0) outStream.write(b);
         b = (byte) (c & 0x00FF);
         outStream.write(b);
      }
   }
]]></jsp:declaration>
<jsp:scriptlet><![CDATA[
   outStream = response.getOutputStream();
   writeGB("<html>");
   writeGB("<meta http-equiv=\"Content-Type\""
      + " content=\"text/html; charset=gb2312\"/>");
   writeGB("<body>");
   writeGB("<b>\uCBB5\uC3F7</b>");
   writeGB("<p>\uD5E2\uCAC7\uD2BB\uB7DD\uB7C7\uB3A3\uBCE4\uB5A5"
      + "\uB5C4\uCBB5\uC3F7\uCAE9\uA1AD</p>");
   writeGB("</body>");
   writeGB("</html>");
]]></jsp:scriptlet>
</jsp:root>

When I opened HelpGB2312Java.jspx with IE, I saw Chinese characters correctly displayed on the screen. So option 1 works! But note that:

Figuring out the byte sequences of non ASCII characters in a particular encoding is not that hard. Simplified Chinese text files are usually written in byte sequences of GB2312 encoding.
Java "char" has 2 bytes. If the first byte is 0x00, it needs to be removed based on GB2312 specification.
Byte sequences can only be entered in Java statements in Hex number format.
response.getOutputStream() need to be called before any other output statements.
Once response.getOutputStream() is called, you can not call response.getWriter() any more. So the entire HTML document must be output in binary mode.
You can not add any static HTML text, because that requires response.getWriter().
A JSP directive.page element is needed to set the Content-Type header of the HTML response with the same charset value as the HTML document.