用Java将字符串的首字母转换大小写

  //首字母转小写
  public static String toLowerCaseFirstOne(String s){
    if(Character.isLowerCase(s.charAt(0)))
      return s;
    else
      return (new StringBuilder()).append(Character.toLowerCase(s.charAt(0))).append(s.substring(1)).toString();
  }
  //首字母转大写
  public static String toUpperCaseFirstOne(String s){
    if(Character.isUpperCase(s.charAt(0)))
      return s;
    else
      return (new StringBuilder()).append(Character.toUpperCase(s.charAt(0))).append(s.substring(1)).toString();
  }