private static boolean isAsciiPrintable(final char ch) {
        return ch >= 32 && ch < 127;
    }

    /**
     * Creates a new String from a char array.
     * <p>
     * Note: This method no longer uses internal JDK APIs for safety and compatibility.
     * It now uses the standard String constructor.
     * </p>
     *
     * @param chars
     *            the char array

  }

  /**
   * Reads a char as specified by {@link DataInputStream#readChar()}, except using little-endian
   * byte order.
   *
   * @return the next two bytes of the input stream, interpreted as a {@code char} in little-endian
   *     byte order
   * @throws IOException if an I/O error occurs
   */
  @CanIgnoreReturnValue // to skip some bytes
  @Override
  public char readChar() throws IOException {

   */
  AppendableWriter(Appendable target) {
    this.target = checkNotNull(target);
  }

  /*
   * Abstract methods from Writer
   */

  @Override
  public void write(char[] cbuf, int off, int len) throws IOException {
    checkNotClosed();
    // It turns out that creating a new String is usually as fast, or faster
    // than wrapping cbuf in a light-weight CharSequence.

   * @param hi the high surrogate pair character
   * @param lo the low surrogate pair character
   */
  public static void assertUnicodeEscaping(
      UnicodeEscaper escaper, String expected, char hi, char lo) {

    int cp = Character.toCodePoint(hi, lo);
    String escaped = computeReplacement(escaper, cp);
    Assert.assertNotNull(escaped);
    Assert.assertEquals(expected, escaped);
  }

   * @param hi the high surrogate pair character
   * @param lo the low surrogate pair character
   */
  public static void assertUnicodeEscaping(
      UnicodeEscaper escaper, String expected, char hi, char lo) {

    int cp = Character.toCodePoint(hi, lo);
    String escaped = computeReplacement(escaper, cp);
    Assert.assertNotNull(escaped);
    Assert.assertEquals(expected, escaped);
  }

    private static final String COMMENT_CHARS = "#!";

    /** The list of possible key/value separators */
    private static final char[] SEPARATORS = new char[] {'=', ':'};

    /** The white space characters used as key/value separators. */
    private static final char[] WHITE_SPACE = new char[] {' ', '\t', '\f'};

    /**
     * Unless standard java props, use UTF-8
     */

    private static final String COMMENT_CHARS = "#!";

    /** The list of possible key/value separators */
    private static final char[] SEPARATORS = new char[] {'=', ':'};

    /** The white space characters used as key/value separators. */
    private static final char[] WHITE_SPACE = new char[] {' ', '\t', '\f'};

    /**
     * Unless standard java props, use UTF-8
     */

        final DecimalFormatSymbols symbols = DecimalFormatSymbolsUtil.getDecimalFormatSymbols(locale);
        final char decimalSep = symbols.getDecimalSeparator();
        final char groupingSep = symbols.getGroupingSeparator();
        final StringBuilder buf = new StringBuilder(20);
        for (int i = 0; i < s.length(); ++i) {
            char c = s.charAt(i);
            if (c == groupingSep) {
                continue;

     */
    public static char[] addAll(final char[] a, final char[] b) {
        if (a == null) {
            return b;
        }
        if (b == null) {
            return a;
        }
        if (a.length == 0) {
            return b;
        }
        if (b.length == 0) {
            return a;
        }
        final char[] array = (char[]) Array.newInstance(char.class, a.length + b.length);

    @Test
    public void testContains_character() throws Exception {
        assertThat(ArrayUtil.contains(new char[] { '1', '2' }, '1'), is(true));
        assertThat(ArrayUtil.contains(new char[] { '1' }, '2'), is(not(true)));
        assertThat(ArrayUtil.contains(new char[] { '2', '1' }, '1'), is(true));
        assertThat(ArrayUtil.contains((char[]) null, '1'), is(not(true)));
    }

    /**
     * @throws Exception
     */
    @Test