CharUtil { public static boolean isWhitespace(char ch) { return ch <= ' '; }  static int toAscii(char ch); static boolean isWhitespace(char ch); static Character toCharacterObject(char ch); static Character toCharacterObject(String str); static char toChar(byte b); static char toChar(Character ch); static char toChar(Character ch, char defaultValue); static char toChar(String str); static char toChar(String str, char defaultValue); static int toIntValue(char ch); static int toIntValue(char ch, int defaultValue); static int toIntValue(Character ch); static int toIntValue(Character ch, int defaultValue); static String toString(char ch); static String toString(Character ch); static String unicodeEscaped(char ch); static String unicodeEscaped(Character ch); static byte[] toSimpleByteArray(char[] carr); static byte[] toSimpleByteArray(CharSequence charSequence); static char[] toSimpleCharArray(byte[] barr); static byte[] toAsciiByteArray(char[] carr); static byte[] toAsciiByteArray(CharSequence charSequence); static byte[] toRawByteArray(char[] carr); static char[] toRawCharArray(byte[] barr); static byte[] toByteArray(char[] carr); static byte[] toByteArray(char[] carr, String charset); static char[] toCharArray(byte[] barr); static char[] toCharArray(byte[] barr, String charset); static boolean equalsOne(char c, char[] match); static int findFirstEqual(char[] source, int index, char[] match); static int findFirstEqual(char[] source, int index, char match); static int findFirstDiff(char[] source, int index, char[] match); static int findFirstDiff(char[] source, int index, char match); static boolean isLowercaseLetter(char c); static boolean isUppercaseLetter(char c); static boolean isLetter(char c); static boolean isDigit(char c); static boolean isLetterOrDigit(char c); static boolean isWordChar(char c); static boolean isPropertyNameChar(char c); static boolean isAscii(char ch); static boolean isAsciiPrintable(char ch); static boolean isAsciiControl(char ch); static boolean isChinese(char c); static char toUpperAscii(char c); static char toLowerAscii(char c);  }
@Test public void isWhitespace() { assertTrue(CharUtil.isWhitespace(' ')); assertTrue(CharUtil.isWhitespace('\t')); assertTrue(CharUtil.isWhitespace('\r')); assertTrue(CharUtil.isWhitespace('\n')); assertFalse(CharUtil.isWhitespace('a')); assertFalse(CharUtil.isWhitespace('0')); assertFalse(CharUtil.isWhitespace('我')); }