Character

Character a = new Character();

Character.isUpperCase(a)    判断给点的字符是否是大写字符

Character.isLowerCase(a)    判断给定的字符是否是小写字符

Character.isDigit(a)    判断给定的字符是否是数字字符

Character.toUpperCase(a)    把给定的字符转换成大写字符

Character.to LowerCase(a)    把给定的字符转换成小写字符