java进行汉字unicode转变成utf-8汉字

/**
     * 将unicode编码转换成汉字
     * @param theString
     * @return
     */
public static String decodeUnicode(String theString) {
char aChar;
int len = theString.length();
StringBuffer outBuffer = new StringBuffer(len);
try {
for (int x = 0; x < len;) {
aChar = theString.charAt(x++);
if (aChar == '\\') {
aChar = theString.charAt(x++);
if (aChar == 'u') {
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);
}
} catch (Exception e) {
// TODO: handle exception
return theString;
}
return outBuffer.toString();
}