银行计算利息

package bank;

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

package bank;

public class BankOfDalian extends Bank {
	double year;
	public double computerInterest()
	{
		super.year=(int)year;
		double r=year-(int)year;
		int day=(int)(r*1000);
		double yearInterest=super.computerInterest();
		double dayInterest=day*0.00012*savedMoney;
		interest=yearInterest+dayInterest;
		System.out.printf("%d元存在大连银行%d年零%d天的利息：%f元
",savedMoney,super.year,day,interest);
		return interest;
	}
}

package bank;

public class ConstructionBank extends Bank {
	double year;
	public double computerInterest()
	{
		super.year=(int)year;
		double r=year-(int)year;
		int day=(int)(r*1000);
		double yearInterest=super.computerInterest();
		double dayInterest=day*0.0001*savedMoney;
		interest=yearInterest+dayInterest;
		System.out.printf("%d元存在建设银行%d年零%d天的利息：%f元
",savedMoney,super.year,day,interest);
		return interest;
	}

}

package bank;

public class SaveMoney {

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