自带测试类
源代码：

package testaccount;public class TestAccount{public static void main(String args[]){Account ss=new Account(1122,20000);ss.setannualInterestRate(4.5);ss.withDraw(2500);ss.deposit(3000);System.out.println("The ss's id is "+ ss.getid());System.out.println("The ss's balance is "+ ss.getbalance());System.out.println("The ss's dateCreated is "+ ss.getdateCreated());}}class Account{private int id=0;private double balance=0;private double annualInterestRate=0;private java.util.Date dateCreated=new java.util.Date();public Account(){}public Account(int newid,int newbalance){id=newid;balance=newbalance;}public int getid(){return id;}public double getbalance(){return balance;}public double getannualInterestRate(){return annualInterestRate;}public void setid(int newid){id=newid;}public void setbalance(double newbalance){balance=newbalance;}public void setannualInterestRate(double newannualInterestRate){annualInterestRate=newannualInterestRate;}public double getMonthlyInterest(){return (annualInterestRate/12)/100;}public String getdateCreated(){return dateCreated.toString();}public void withDraw(double draw){balance-=draw;}public void deposit(double draw){balance+=draw;}}

运行结果：