Java – intをBigIntegerに変換する方法は？

package com.mkyong;

import java.math.BigInteger;

public class JavaExample {

    public static void main(String[]args) {

        int n = 100;
        System.out.println(n);

       //convert int to Integer
        Integer integer = Integer.valueOf(n);
        System.out.println(integer);

       //convert int to BigInteger
        BigInteger bigInteger = BigInteger.valueOf(n);
        System.out.println(bigInteger);

       //convert Integer to BigInteger
       //BigInteger bigInteger2 = BigInteger.valueOf(integer);//works
        BigInteger bigInteger2 = BigInteger.valueOf(integer.intValue());
        System.out.println(bigInteger2);

    }

}

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