Java实现的utf8，gbk，unicode编码相互转换的代码

Java实现的utf8，gbk，unicode编码相互转换的代码

public class UTF2GBK {
	
	public String gbk2utf8(String gbk) {
		String l_temp = GBK2Unicode(gbk);
		l_temp = unicodeToUtf8(l_temp);
		return l_temp;
	}
	public String utf82gbk(String utf) {
		String l_temp = utf8ToUnicode(utf);
		l_temp = Unicode2GBK(l_temp);
		return l_temp;
	}
	/**
	 * 
	 * @param str
	 * @return String
	 */
	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 (!isNeedConvert(chr1)) {
				result.append(chr1);
				continue;
			}
			result.append("\\u" + Integer.toHexString((int) chr1));
		}
		return result.toString();
	}
	/**
	 * 
	 * @param dataStr
	 * @return String
	 */
	public static String Unicode2GBK(String dataStr) {
		int index = 0;
		StringBuffer buffer = new StringBuffer();
		int li_len = dataStr.length();
		while (index < li_len) {
			if (index >= li_len - 1
					|| !"\\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);
			buffer.append(letter);
			index += 6;
		}
		return buffer.toString();
	}
	public static boolean isNeedConvert(char para) {
		return ((para & (0x00FF)) != para);
	}
	/**
	 * utf-8 转unicode
	 * 
	 * @param inStr
	 * @return String
	 */
	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) {
				sb.append(myBuffer[i]);
			} else if (ub == UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS) {
				int j = (int) myBuffer[i] - 65248;
				sb.append((char) j);
			} else {
				short s = (short) myBuffer[i];
				String hexS = Integer.toHexString(s);
				String unicode = "\\u" + hexS;
				sb.append(unicode.toLowerCase());
			}
		}
		return sb.toString();
	}
	/**
	 * 
	 * @param theString
	 * @return String
	 */
	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   \\uxxxx   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();
	}
}