Java代码如何判断字符串中是不是都是数字呢?

实现思路:
  正则判断
   或
  借助Character.isDigit方法判断
   或
  char值码匹配
   或
  使用Long中的parse方法判断

package com.java265.test2;
import java.util.regex.Pattern;
 
/**
 * Description: 检验数字字符
 */
public class IsNumberDemo {
    public static void main(String[] args) {
        System.out.println("isNumber1:" + isNumber1("8293222525")); //true
        System.out.println("isNumber2:" + isNumber1("8293222525")); //true
        System.out.println("isNumber3:" + isNumber1("82932$22525")); //false
        System.out.println("isNumber4:" + isNumber1("82932#22525")); //false
    }
 
    //方法1 正则表达式
    private static final Pattern MATCH_PATTERN = Pattern.compile("-?\\d+(\\.\\d+)?");
 
    public static boolean isNumber1(String str) {
        return str != null && MATCH_PATTERN.matcher(str).matches();
    }
 
    //方法2 Stream流(推荐)
    public static boolean isNumber2(String str) {
        return str != null && str.chars().allMatch(Character::isDigit);
    }
 
    //方法3 char码值匹配
    public static boolean isNumber3(String str) {
        for (int i = 0; i < str.length(); i++) {
            char c = str.charAt(i);
            if (c < 48 || c > 57) {
                return false;
            }
        }
        return true;
    }
 
    //方法4 使用Long封装类的parse方法
    public static boolean isNumber4(String str) {
        try {
            Long.parseLong(str);
            return true;
        } catch(Exception e){
            return false;
        }
    }
}