判斷字符串是否爲正整數 & 浮點小數

/** * 判斷字符串是否爲數字(正整數和浮點數) * @param str * @return */public static boolean isNumeric(String str) {    String reg = "^[0-9]+(.[0-9]+)?$";    Pattern pattern = Pattern.compile(reg);    Matcher isNum = pattern.matcher(str);    if (!isNum.matches()) {        return false;    }    return true;}