Java String Unicode Value

Question

How can I get the unicode value of a string in java?

For example if the string is \"Hi\" I need something like \\uXXXX\\uXXXX

Answer 1

This method converts an arbitrary String to an ASCII-safe representation to be used in Java source code (or properties files, for example):

public String escapeUnicode(String input) {
  StringBuilder b = new StringBuilder(input.length());
  Formatter f = new Formatter(b);
  for (char c : input.toCharArray()) {
    if (c < 128) {
      b.append(c);
    } else {
      f.format("\\u%04x", (int) c);
    }
  }
  return b.toString();
}

Answer 2

Some unicode characters span two Java chars. Quote from http://docs.oracle.com/javase/tutorial/i18n/text/unicode.html :

The characters with values that are outside of the 16-bit range, and within the range from 0x10000 to 0x10FFFF, are called supplementary characters and are defined as a pair of char values.

correct way to escape non-ascii:

private static String escapeNonAscii(String str) {

  StringBuilder retStr = new StringBuilder();
  for(int i=0; i<str.length(); i++) {
    int cp = Character.codePointAt(str, i);
    int charCount = Character.charCount(cp);
    if (charCount > 1) {
      i += charCount - 1; // 2.
      if (i >= str.length()) {
        throw new IllegalArgumentException("truncated unexpectedly");
      }
    }

    if (cp < 128) {
      retStr.appendCodePoint(cp);
    } else {
      retStr.append(String.format("\\u%x", cp));
    }
  }
  return retStr.toString();
}