在java中，将utf-8字符码影射成汉字

以下是一个字符码转换的工具。
在此留个记号，只能运行在jdk1.6下。
utf16这个类在jre/lib/rt.jar下。

/*
 * (#)CharsetConvertor.java 1.0 2009-8-19  
 */
package com.codelib.util;

import java.io.UnsupportedEncodingException;
import java.lang.Character.UnicodeBlock;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import sun.text.normalizer.UTF16;

/**
 * @author 赵博
 * @version $1.0, 2009-8-19
 * @since JDK6
 */
public class CharsetConvertor
{
	public static void main(String[] args)
	{

		try
		{
			String s = "中国人";
			System.out.println(s);
			System.out.println(s.getBytes().length);
			String fullByte = CharsetConvertor.utf8ToUnicode(s);
			System.out.println(fullByte);
			System.out.println(CharsetConvertor.Unicode2GBK(fullByte));
			System.out.println(CharsetConvertor.Unicode2GBK(fullByte).getBytes("gbk").length);
			 
			// String fullStr = new String( fullByte.getBytes(), "UTF-8");
			// System.out.println("string from GBK to UTF-8 byte:  " + fullStr);

		}
		catch (Exception e)
		{
			e.printStackTrace();
		}
	}

	/**
	 * @param chinese
	 * @return
	 */
	public static byte[] gbk2utf8(String chinese)
	{
		char c[] = chinese.toCharArray();
		byte[] fullByte = new byte[3 * c.length];
		for (int i = 0; i < c.length; i++)
		{
			int m = (int) c[i];
			String word = Integer.toBinaryString(m);
			// System.out.println(word);

			StringBuffer sb = new StringBuffer();
			int len = 16 - word.length();
			// 锟斤拷锟斤拷
			for (int j = 0; j < len; j++)
			{
				sb.append("0");
			}
			sb.append(word);
			sb.insert(0, "1110");
			sb.insert(8, "10");
			sb.insert(16, "10");

			// System.out.println(sb.toString());

			String s1 = sb.substring(0, 8);
			String s2 = sb.substring(8, 16);
			String s3 = sb.substring(16);

			byte b0 = Integer.valueOf(s1, 2).byteValue();
			byte b1 = Integer.valueOf(s2, 2).byteValue();
			byte b2 = Integer.valueOf(s3, 2).byteValue();
			byte[] bf = new byte[3];
			bf[0] = b0;
			fullByte[i * 3] = bf[0];
			bf[1] = b1;
			fullByte[i * 3 + 1] = bf[1];
			bf[2] = b2;
			fullByte[i * 3 + 2] = bf[2];

		}
		return fullByte;
	}

	/**
	 * utf-8 转换�?unicode
	 * 
	 * @author fanhui 2007-3-15
	 * @param inStr
	 * @return
	 */
	public static String utf8ToUnicode(String inStr)
	{
		char[] myBuffer = inStr.toCharArray();

		StringBuffer sb = new StringBuffer();
		for (int i = 0; i < inStr.length(); i++)
		{
			UnicodeBlock ub = UnicodeBlock.of(myBuffer[i]);
			if (ub == UnicodeBlock.BASIC_LATIN)
			{
				// 英文及数字等
				sb.append(myBuffer[i]);
			}
			else if (ub == UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS)
			{
				// 全角半角字符
				int j = (int) myBuffer[i] - 65248;
				sb.append((char) j);
			}
			else
			{
				// 汉字
				short s = (short) myBuffer[i];
				String hexS = Integer.toHexString(s);
				String unicode = "\\u" + hexS;
				sb.append(unicode.toLowerCase());
			}
		}
		return sb.toString();
	}

	/**
	 * unicode 转换�?utf-8
	 * 
	 * @author fanhui 2007-3-15
	 * @param theString
	 * @return
	 */
	public static String unicodeToUtf8(String theString)
	{
		char aChar;
		int len = theString.length();
		StringBuffer outBuffer = new StringBuffer(len);
		for (int x = 0; x < len;)
		{
			aChar = theString.charAt(x++);
			if (aChar == '\\')
			{
				aChar = theString.charAt(x++);
				if (aChar == 'u')
				{
					// Read the xxxx
					int value = 0;
					for (int i = 0; i < 4; i++)
					{
						aChar = theString.charAt(x++);
						switch (aChar)
						{
							case '0':
							case '1':
							case '2':
							case '3':
							case '4':
							case '5':
							case '6':
							case '7':
							case '8':
							case '9':
								value = (value << 4) + aChar - '0';
								break;
							case 'a':
							case 'b':
							case 'c':
							case 'd':
							case 'e':
							case 'f':
								value = (value << 4) + 10 + aChar - 'a';
								break;
							case 'A':
							case 'B':
							case 'C':
							case 'D':
							case 'E':
							case 'F':
								value = (value << 4) + 10 + aChar - 'A';
								break;
							default:
								throw new IllegalArgumentException("Malformed   <a><font color=#4563b9>\\uxxxx</font></a>   encoding.");
						}
					}
					outBuffer.append((char) value);
				}
				else
				{
					if (aChar == 't')
						aChar = '\t';
					else if (aChar == 'r')
						aChar = '\r';
					else if (aChar == 'n')
						aChar = '\n';
					else if (aChar == 'f')
						aChar = '\f';
					outBuffer.append(aChar);
				}
			}
			else
				outBuffer.append(aChar);
		}
		return outBuffer.toString();
	}

	/**
	 * 中文转unicode
	 * 
	 * @param str
	 * @return 反回unicode编码
	 */

	public static String GBK2Unicode(String str)
	{

		StringBuffer result = new StringBuffer();

		for (int i = 0; i < str.length(); i++)
		{

			char chr1 = (char) str.charAt(i);

			if (!CharsetConvertor.isNeedConvert(chr1))
			{

				result.append(chr1);

				continue;

			}

			result.append("\\u" + Integer.toHexString((int) chr1));

		}

		return result.toString();

	}

	/**
	 * unicode转中�?
	 * 
	 * @param str
	 * @return 中文
	 */

	public static String Unicode2GBK(String dataStr)
	{

		int index = 0;

		StringBuffer buffer = new StringBuffer();

		while (index < dataStr.length())
		{

			if (!"\\u".equals(dataStr.substring(index, index + 2)))
			{

				buffer.append(dataStr.charAt(index));

				index++;

				continue;

			}

			String charStr = "";

			charStr = dataStr.substring(index + 2, index + 6);
			char letter = (char) Integer.parseInt(charStr, 16);
			try
			{
				System.out.println("byte length="+(letter+"").getBytes("gbk").length);
				buffer.append(new String((letter+"").getBytes("gbk"),"gbk"));
			}
			catch (UnsupportedEncodingException e)
			{
				e.printStackTrace();
			}

			index += 6;

		}

		return buffer.toString();

	}

	public static boolean isNeedConvert(char para)
	{

		return ((para & (0x00FF)) != para);

	}
	/**
	 * 将文件名中的汉字转为UTF8编码的串,以便下载时能正确显示另存的文件名.
	 * 
	 * @param s
	 *            原文件名
	 * @return 重新编码后的文件名
	 * @author yue
	 */
	public static String toUtf8String(String s)
	{
		if (s == null || s.equals(""))
		{
			return null;
		}
		StringBuffer sb = new StringBuffer();
		try
		{
			char c;
			for (int i = 0; i < s.length(); i++)
			{
				c = s.charAt(i);
				if (c >= 0 && c <= 255)
				{
					sb.append(c);
				}
				else
				{
					byte[] b;

					b = Character.toString(c).getBytes("utf-8");

					for (int j = 0; j < b.length; j++)
					{
						int k = b[j];
						if (k < 0)
							k += 256;
						sb.append("%" + Integer.toHexString(k).toUpperCase());
					}
				}
			}
		}
		catch (Exception e)
		{
			e.printStackTrace();
		}
		return sb.toString();
	}

	/**
	 * 将10进制的utf-8字符码，映射成为汉字。
	 * 
	 * @param code
	 * @return
	 */
	public static String utf8decode(String code)
	{
		Pattern regex = Pattern.compile("&#\\d{5};");
		Matcher matcher = regex.matcher(code);
		int index = 0;
		while (matcher.find())
		{
			code = code.replaceAll(matcher.group(index), UTF16.valueOf(Integer.parseInt(matcher.group(index).replaceAll("[#&;]", ""))));

		}

		return code;
	}
}

如果有同学有更好的方法，请在此留下你的脚印。