Java 常用类库 之 大精度数值

http://www.verejava.com/?id=17159675312132

import java.math.BigDecimal;
import java.math.BigInteger;

public class Test {

    public static void main(String[] args) {
        // 计算 1 到 30 的相乘的结果
        BigInteger sum = new BigInteger("1");
        for (int i = 1; i <= 30; i++) {
            sum = sum.multiply(new BigInteger(String.valueOf(i)));
        }
        System.out.println(sum);

        BigInteger bi1 = new BigInteger("20000000002000000002");
        BigInteger bi2 = new BigInteger("40000000004000000004");
        System.out.println(bi1.add(bi2));
        System.out.println(bi2.subtract(bi1));
        System.out.println(bi1.divide(new BigInteger("2")));

        BigDecimal bd1 = new BigDecimal("20000000002000000000.0000000002");
        BigDecimal bd2 = new BigDecimal("30000000003000000000.0000000003");
        System.out.println(bd1.add(bd2));
        System.out.println(bd2.subtract(bd1));
        System.out.println(bd2.divide(new BigDecimal("2")));
        System.out.println(bd2.multiply(new BigDecimal("2")));

    }
}

http://www.verejava.com/?id=17159675312132