/*
* Copyright (c) 2002-2003 Che, Dong Email: chedongATbigfoot.com/chedongATchedong.com
* $Id: HelloUnicodeServlet.java,v 1.4 2003/04/19 03:34:39 chedong Exp $
*/
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 一个简单的Servlet试验：用于说明如何自动根据HTTP头中的"Accept-Language"
* 检测客户端的语言字符集设置，正确的将请求中的内容解码，并将内容用正确的
* 编码方式编码反馈给客户端。
*
* @author Che, Dong
*/
public class HelloUnicodeServlet extends HttpServlet {
/**
* Brower language detection demo
* @param req HTTP Servlet Request
* @param res HTTP Servlet Response
* @throws ServletException servlet error
* @throws IOException io error
*/
public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
String clientLanguage = req.getHeader("Accept-Language");
/*
* comment following code to disable brower language detection
*/
if (clientLanguage.equals("zh-cn")) {
//for Simplied Chinese
req.setCharacterEncoding("GBK");
res.setContentType("text/html; charset=GBK");
} else if (clientLanguage.equals("zh-tw")) {
//for Traditional Chinese
req.setCharacterEncoding("BIG5");
res.setContentType("text/html; charset=BIG5");
} else {
//default encoding
req.setCharacterEncoding("ISO-8859-1");
res.setContentType("text/html; charset=ISO-8859-1");
}
//defualt hello string
String hello = "hello world";
if (req.getParameter("hello") != null) {
hello = req.getParameter("hello").trim();
}
PrintWriter pw = res.getWriter();
pw.println(
"");
pw.println("");
pw.println("");
pw.println("" + hello + "");
pw.println("");
pw.println();
pw.println("");
pw.println();
pw.println("'" + hello + "' length=" + hello.length()
+ "
");
//print current request and response charset encoding
pw.println("ServletRequest's Charset Encoding = "
+ req.getCharacterEncoding());
pw.println("
");
pw.println("ServletResponse's Charset Encoding = "
+ res.getCharacterEncoding());
pw.println("
");
//print char array
pw.println(getCharArray(hello));
//show input form
pw.println("");
//print system properties
pw.println("");
System.getProperties().list(pw);
pw.println("");
pw.println("");
pw.close();
}
/**
* print char array
* @param inStr input String
* @return String output String
*/
private static String getCharArray(String inStr) {
char[] myBuffer = inStr.toCharArray();
StringBuffer sb = new StringBuffer();
//list each Charactor in byte value, short value, and UnicodeBlock Mapping
for (int i = 0; i < inStr.length(); i++) {
byte b = (byte) myBuffer[i];
short s = (short) myBuffer[i];
String hexB = Integer.toHexString(b).toUpperCase();
String hexS = Integer.toHexString(s).toUpperCase();
//print char
sb.append("char[");
sb.append(i);
sb.append("]='");
sb.append(myBuffer[i]);
sb.append("'\t");
//byte value
sb.append("byte=");
sb.append(b);
sb.append(" \\u");
sb.append(hexB);
sb.append('\t');
//short value
sb.append("short=");
sb.append(s);
sb.append(" \\u");
sb.append(hexS);
sb.append('\t');
//Unicode Block
sb.append(Character.UnicodeBlock.of(myBuffer[i]));
sb.append("
");
}
return sb.toString();
}
}