Java封装一个ShowDate类，封装一个ComputerBig类，封装一个JavaComputerDate

第八题：

主类

    public static void main(String[] args){
        GregorianCalendar calendar = (GregorianCalendar) GregorianCalendar.getInstance();
        ShowDate showDate = new ShowDate();
        showDate.show(calendar);
        calendar.setTimeInMillis(123456789765L);
        showDate.show(calendar);
    }

ShowDate类

public class ShowDate {

    public void show(GregorianCalendar calendar){
        String year = String.valueOf(calendar.get(GregorianCalendar.YEAR));
        String month = String.valueOf(calendar.get(GregorianCalendar.MONTH)+1);
        String day = String.valueOf(calendar.get(GregorianCalendar.DAY_OF_MONTH));
        System.out.println(year+"年"+month+"月"+day+"日");
    }
}

第九题：

主类

public class Test {
     public static void main(String[] args){
         ComputerBig computerBig = new ComputerBig("12345", "987654321987654321987654321");
         computerBig.add();
         computerBig.substract();
         computerBig.multiply();
         computerBig.divide();
         computerBig.Function();
     }
     //当数过大时无法求出他的因子个数
}

ComputerBig类

public class ComputerBig {
    BigInteger num1;
    BigInteger num2;
    public ComputerBig(String a,String b){
        this.num1 = new BigInteger(a);
        this.num2 = new BigInteger(b);
    }

    public void add(){
        BigInteger a3 = num1.add(num2);
        System.out.println("两数之和为"+a3);
    }
    public void substract(){
        BigInteger a3 = num1.subtract(num2);
        System.out.println("两数之差为"+a3);
    }
    public void multiply(){
        BigInteger a3 = num1.multiply(num2);
        System.out.println("两数之积为"+a3);
    }
    public void divide(){
        BigDecimal a1 = new BigDecimal(num1);
        BigDecimal a2 = new BigDecimal(num2);
        BigDecimal a3 = a1.divide(a2,30,BigDecimal.ROUND_UP);
        System.out.println("两数之商为"+a3);
    }
    public void Function(){
        int count = 0;
        BigInteger i = BigInteger.valueOf(2);
        for (; i.compareTo(num1) < 0; i = i.add(BigInteger.ONE)){
            if (num1.remainder(i).equals(BigInteger.ZERO))
                count++;
        }
        System.out.println(num1+"的因子个数为"+count);
    }


}

第十题：

主类

public class Test {
    public static void main(String[] args){
        Calendar a=Calendar.getInstance();
        a.set(2006, 6,6 );
        Calendar b=Calendar.getInstance();
        b.set(2008, 8,3 );
        JavaComputerDate j = new JavaComputerDate(a, b);
        j.compare();
    }
}

JavaComputerDate类

public class JavaComputerDate {
    Calendar a,b;
    long a1,b1;
    public JavaComputerDate(Calendar a,Calendar b){
        this.a=a;
        this.b=b;
        a1=a.getTimeInMillis();
        b1=b.getTimeInMillis();
    }

    public void compare(){
        if(a1>b1){
            System.out.println("您输入的第一个日期大于第二个日期");
            long a3 = (a1 - b1)/(1000*3600*24)-1;
            System.out.print(a.get(Calendar.YEAR)+"年"+a.get(Calendar.MONTH)+"月"+a.get(Calendar.DAY_OF_MONTH)+"日");
            System.out.print("和"+b.get(Calendar.YEAR)+"年"+b.get(Calendar.MONTH)+"月"+b.get(Calendar.DAY_OF_MONTH)+"日");
            System.out.println("相隔"+a3+"天");
        }


        else if(a1<b1){
            System.out.println("您输入的第二个日期大于第一个日期");
            long a3 = (b1 - a1)/(1000*3600*24)-1;
            System.out.print(a.get(Calendar.YEAR)+"年"+a.get(Calendar.MONTH)+"月"+a.get(Calendar.DAY_OF_MONTH)+"日");
            System.out.print("和"+b.get(Calendar.YEAR)+"年"+b.get(Calendar.MONTH)+"月"+b.get(Calendar.DAY_OF_MONTH)+"日");
            System.out.println("相隔"+a3+"天");
        }

        else
            System.out.println("您输入的两个日期相等");
    }

}