java chapter07-1

package bank;

public class Bank {
	int saveMoney;
	int year;
	double interest;
	double interestRate = 0.29;
	public double computerInterest(){
		interest = year*interestRate*saveMoney;
		return interest;
	}
	public void setInterestRate(double rate){
		interestRate = rate;
	}
}

package bank;

public class BankOfDalian extends Bank{
	double year;
	//computerInterest的重写
	public double computerInterest(){
		super.year = (int)year;
		double r = year - (int)year;
		int day = (int)(r*1000);
		//super调用隐函数computerInterest()的方法
		double yearInterest = super.computerInterest();
		double dayInterest = day*0.00012*saveMoney;
		interest = yearInterest+dayInterest;
		System.out.printf("%d元存在大连银行%d年零%d天的利息：%f元\n",saveMoney,super.year,day,interest);
		return interest;
	}
}

package bank;

public class ConstructionBank extends Bank{
	double year;
	//computerInterest的重写
	public double computerInterest(){
		super.year = (int)year;
		double r = year - (int)year;
		int day = (int)(r*1000);
		//super调用隐函数computerInterest()的方法
		double yearInterest = super.computerInterest();
		double dayInterest = day*0.0001*saveMoney;
		interest = yearInterest+dayInterest;
		System.out.printf("%d元存在建设银行%d年零%d天的利息：%f元\n",saveMoney,super.year,day,interest);
		return interest;
	}
}

package bank;

public class Test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int amount = 8000;
		ConstructionBank bank1 = new ConstructionBank();
		bank1.saveMoney = amount;
		bank1.year = 8.236;
		bank1.setInterestRate(0.035);
		double interest1 = bank1.computerInterest();
		BankOfDalian bank2 = new BankOfDalian();
		bank2.saveMoney = amount;
		bank2.year = 8.236;
		bank2.setInterestRate(0.036);
		double interest2 = bank2.computerInterest();
		System.out.printf("两个银行利息相差%f元\n",interest2 - interest1);
	}

}