Java之BigInteger的用法

Java之BigInteger用法

BigInteger在Java中用于操作大整数，当一个数超过了Long表示的最大范围时就可以考虑使用BigInteger来操作。

BigInteger的使用方法很多，也可以用于进制转换的一些操作，本文记录了一些BigInteger的常用方法。

一、常用方法

		BigInteger number1 = new BigInteger("4324234132412");
        BigInteger number2 = new BigInteger("54323423423432");
        BigInteger result;
        number1 = number1.add(number2);
        number2 = number2.subtract(number1);
        number2 = number1.multiply(number2);
        number2 = number1.divide(number2);
        number2 = number2.remainder(number1);
        number2 = number2.pow(10);
        number2 = number2.remainder(number1);
        number2 = number2.gcd(number1);
        result = number2.min(number1);
        result = number2.and(number1);
        result = number2.or(number1);
        result = number2.andNot(number1);
        result = number2.not();
        result = number2.xor(number1);
        result = number2.shiftLeft(10);
        result = number2.shiftRight(6);
        BigInteger number3 = new BigInteger("10");
        System.out.println(number3.bitLength());
        System.out.println(number2);
        if (number1.compareTo(number2) > 0) {
            System.out.println("a > b");
        } else if (number1.compareTo(number2) < 0) {
            System.out.println("a < b");
        } else {
            System.out.println("a = b");
        }

二、进制转换

利用BigInteger的构造函数可以实现任意进制的转换。

		// 十进制转二进制
		String str1 = new BigInteger("100", 10).toString(2);
        System.out.println(str1);
		// 二进制转十进制
        String str2 = new BigInteger("1010101010111", 2).toString(10);
        System.out.println(str2);
		// 十六进制转八进制
        String str3 = new BigInteger("7E6A", 16).toString(8);
        System.out.println(str3);