判断字符串是否是纯数字的几种常用方法

package com.sunlibin;

import java.util.regex.Pattern;

public class StringUtil {

    /**
     * 正则表达式法
     * @param str
     * @return
     */
    public static boolean isNumberStr(String str){
        if (str != null && !"".equals(str.trim())){
            return str.matches("^[0-9]*$");
        }else{
            return false;
        }
    }

    /**
     * 通过解析字符串异常捕获
     * @param str
     * @return
     */
    public static boolean isNumberStr2(String str) {
        try {
            Double.parseDouble(str);
            return true;
        } catch(Exception e){
            return false;
        }
    }

    public static boolean isNumberStr3(String str) {
        return str != null && str.matches("-?\\d+(\\.\\d+)?");
    }

    public static boolean isNumberStr4(String str) {
        Pattern pattern = Pattern.compile("-?\\d+(\\.\\d+)?");
        return str != null && pattern.matcher(str).matches();
    }

}

参考文档链接：

https://blog.youkuaiyun.com/mryang125/article/details/113146057?utm_source=app&app_version=4.5.3
https://www.runoob.com/java/java-regular-expressions.html