（管用）java正则表达式判断是否是数字

public static boolean isNumericZidaiZhengZe(String str) {
        Pattern pattern = Pattern.compile("-?[0-9]+.?[0-9]+");
        Matcher isNum = pattern.matcher(str);
        if (!isNum.matches()) {
            return false;
        }
        return true;
    }