Lab Report11

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11.1

 Design a Transaction class as follows:

■  A private data field to store the the date of this transaction.

■  A private data field to store the type of the transaction, such as 'W' for withdrawal, 'D'

■  A private data field to store the amount of the transaction.

■  A private data field to store the new balance after this transaction.

■  The getter methods for all above private data fields.

■  A constructor to construct a Transaction with the specified date, type, balance, and description.

Modify the given Account class as follows:

■ Add a new data field name of the String type to store the name of the customer.

■ Add a new constructor that constructs an account with the specified name, id, and balance.

■ Add a new data field named transactions whose type is ArrayList that stores the transaction for the accounts. Each transaction is an instance of the Transaction class.

■ Modify the withdraw and deposit methods to add a transaction to the transactions array list.

The UML of Account class and Transaction class is shown as the following.

Write a test program that creates an Account with annual interest rate 1.5%, balance 1000, id 1122, and name George. Deposit $30, $40, and $50 to the account and withdraw $5, $4, and $2 from the account. Print an account summary that shows account holder name, interest rate, balance, and all transactions.

 Test example:

//只略微解释了一下
import java.util.Date;
import java.util.Scanner;
import java.util.ArrayList;
class Account{
	protected String name;
	protected int id;
	protected double balance;
	protected double annualInterestRate;
	protected Date dateCreated=new Date();
	ArrayList<Transaction> trancsaction=new ArrayList<Transaction>(); //此处说明队列里只能存放Transaction类实例的地址
	Account(){
		
	}
	Account(String name,int newId,double newBalance,double annualInterestRate){
		this.name=name;
		id=newId;
		balance=newBalance;
		this.annualInterestRate=annualInterestRate;
	}
	String getName() {
		return name;
	}
	int getId() {
		return id;
	}
	double getBanlance() {
		return balance;
	}
	double getAnnualInterestRate() {
		return annualInterestRate;
	}
	void setId(int newId) {
		id=newId;
	}
	void setBalance(double newBalance) {
		balance=newBalance;
	}
	void setAnnualInterestRate(double newAnnualInterestRate) {
		annualInterestRate=newAnnualInterestRate;
	}
	double getMonthlyInterest() {
		return (annualInterestRate/12)*balance;
	}
	Date getDateCreated() {
		return dateCreated;
	}
	void withdraw(double amount) {
		balance=balance-amount;
		String b= new String(dateCreated.toString()+"   "+"W        "+amount+"         "+balance+amount);
		this.trancsaction.add(new Transaction('W',amount,balance+amount,b));
	}  //因为要记录取钱的信息，所以要构造一个Transaction对象，把描述本次操作的字符串b作为构造器传递的String类的description，并且要把Transaction对象放在队列里，所以用add方法。
	void deposit(double amount) {
		balance=balance+amount;
		String b= new String(dateCreated.toString()+"   "+"D        "+amount+"        "+balance+amount);
		this.trancsaction.add(new Transaction('D',amount,this.balance-amount,b));
	}//基本同上
}
class Transaction{
	private Date date;
	private char type;
	private double amount;
	private double balance;
	private String description;
	Transaction(char type,double amount,double balance,String description){
		this.type=type;
		this.amount=amount;
		this.balance=balance;
		this.description=description;
	}
	Date getDate() {
		return date;
	}
	char getChar() {
		return type;
	}
	double getAmount() {
		return amount;
	}
	double getBalance() {
		return balance;
	}
	String getDescription() {
		return description;
	}
}
public class main {
	public static void main(String[] args) {
		Account a=new Account("George",1122,1000,1.5);
		a.deposit(30);
		a.deposit(40);
		a.deposit(50);
		a.withdraw(5.0);
		a.withdraw(4.0);
		a.withdraw(2.0);
		System.out.println("Name : "+a.getName());
		System.out.println("Annual interest rate : "+a.getAnnualInterestRate()+"%");
		System.out.println("Balance : "+a.getBanlance());
		System.out.println("Date                          Type      Amount     Balance");
		for(int i=0;i<a.trancsaction.size();i++) {
			System.out.println(a.trancsaction.get(i).getDescription());
		}
	}
}