java大整数用法与排序

import java.math.BigInteger;
import java.util.Scanner;
   
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        BigInteger n = sc.nextBigInteger();
        n=n.mod(BigInteger.valueOf(1000000006));
        BigInteger m = sc.nextBigInteger();
        BigInteger one = BigInteger.ONE;
        BigInteger cmp =new BigInteger("1000000007");
        BigInteger res =  one;
        while(n.compareTo(one)>=0) {
            res = res.add(res);
            if(res.compareTo(cmp)>=0)
                res=res.mod(cmp);
            one = one.add(BigInteger.ONE);
        }
        System.out.print(res);
    }
}

Arrays.sort()

import java.lang.reflect.Array;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.*;

public class Main {

    public static void main(String[] args) {
        Scanner cin=new Scanner(System.in);
        BigInteger a[]={BigInteger.valueOf(5), BigInteger.valueOf(5), BigInteger.valueOf(7), 
                BigInteger.valueOf(2), BigInteger.valueOf(0)};
        Comparator cmp = new MyComparator();
        Arrays.sort(a, cmp);
        System.out.println(Arrays.toString(a));
    }
    static class MyComparator implements Comparator<BigInteger>//从大到小排序
    {
        @Override
        public int compare(BigInteger o1, BigInteger o2) {
            if(o1.compareTo(o2)<=0)
                return 1;
            else if(o1.compareTo(o2)==0)
                return 0;
            else
                return -1;
        }

    }
}