将string中的unicode转为汉字 其他不变

public String unescapeUnicode(String str){
StringBuffer c = new StringBuffer();
Matcher m = Pattern.compile("\\\\u([0-9a-fA-F]{4})").matcher(str);
while(m.find()) {
StringBuffer b = new StringBuffer();
b.append((char)Integer.parseInt(m.group(1),16));
m.appendReplacement(c, b.toString());
}
m.appendTail(c);
return c.toString();
}