Zeichenketten in Unicode-Strings umwandeln

"abcd1234567890äöüß"

"\u0061\u0062\u0063\u0064\u0031\u0032\u0033\u0034\u0035\u0036\u0037\u0038\u0039\u0030\u00e4\u00f6\u00fc\u00df"

 private final static String UNICODE_PREFIX = "\\u";
...
 public static String toUnicodeString(String unicodeInput, String inputEncoding) {

  StringBuffer unicodeStringBuffer = new StringBuffer();
  String unicodeString = null;

  try {
   String utf8String = new String(unicodeInput.getBytes(inputEncoding), "UTF-8");
   String hexValueString = null;
   int hexValueLength = 0;
   for (int i = 0; i < utf8String.length(); i++) {

    hexValueString = Integer.toHexString(utf8String.charAt(i));
    hexValueLength = hexValueString.length();
    if (hexValueLength < 4) {
     for (int j = 0; j < (4 - hexValueLength); j++)
      hexValueString = "0" + hexValueString;
    }

    unicodeStringBuffer.append(UNICODE_PREFIX);
    unicodeStringBuffer.append(hexValueString);
   }
   unicodeString = unicodeStringBuffer.toString();
  } catch (UnsupportedEncodingException e) {
   e.printStackTrace();
  }
  return unicodeString;
 }