Java练手之Bank项目实现

朴灿烈づ我的快乐病毒、 2021-09-21 12:14 413阅读 0赞

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文件目录：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzQxNjY2MTk4_size_16_color_FFFFFF_t_70 1][]

Account类：

package com.lukuan.javase.banking;
    
    public class Account {
    
    	protected double balance;
    	
    	public Account(double init_balance){
    		this.balance = init_balance;
    	}
    	
    	public double getBalance() {
    		return balance;
    	}
    	
    	public boolean deposit(double amt){
    		this.balance += amt;
    		return true;
    	}
    	
    	public void withdraw(double amt) {
    
    		if(amt > balance){
    			throw new OverdraftException("支付失败，尚需", amt - balance);
    		}
    		
    		this.balance -= amt;
    	}
    	
    }

SavingAccount类：

package com.lukuan.javase.banking;
    
    public class SavingAccount extends Account{
    
    	private double interestRate;
    	
    	public SavingAccount(double init_balance, double interestRate) {
    		super(init_balance);
    		this.interestRate = interestRate;
    	}
    
    }

CheckingAccount类：

package com.lukuan.javase.banking;
    
    public class CheckingAccount extends Account{
    
    	private Double overdraftProtection;
    	
    	public CheckingAccount(double init_balance) {
    		super(init_balance);
    	}
    	
    	public CheckingAccount(double init_balance, double overdraftProtection){
    		super(init_balance);
    		this.overdraftProtection = overdraftProtection;
    	}
    	
    
    	@Override
    	public void withdraw(double amt) {
    		if(balance >= amt){
    			balance -= amt;
    		}else{
    			if(overdraftProtection == null){
    				throw new OverdraftException("no overdraft protection", (amt - balance));
    			}
    			if(overdraftProtection >= (amt - balance)){
    				overdraftProtection -= (amt - balance);
    				balance = 0;
    			}else{
    				throw new OverdraftException("Insufficient funds for overdraft protection", (amt - balance));
    			}
    		}
    		
    	}
    	
    }

Customer类：

package com.lukuan.javase.banking;
    
    import java.util.ArrayList;
    import java.util.Iterator;
    import java.util.List;
    
    public class Customer {
    	
    	private String firstName;
    	private String lastName;
    	
    	private List<Account> accounts;
    	
    	public Customer(String firstName, String lastName) {
    		this.firstName = firstName;
    		this.lastName = lastName;
    		
    		accounts = new ArrayList<Account>();
    	}
    
    	public Account getAccount(int index) {
    		return accounts.get(index);
    	}
    
    	public void addAccount(Account account) {
    		accounts.add(account);
    	}
    
    	public String getFirstName() {
    		return firstName;
    	}
    
    	public String getLastName() {
    		return lastName;
    	}
    	
    	public int getNumOfAccounts(){
    		return accounts.size();
    	}
    	
    	public Iterator<Account> getAccounts(){
    		return accounts.iterator();
    	}
    }

Bank类：

package com.lukuan.javase.banking;
    
    import java.util.ArrayList;
    import java.util.Iterator;
    import java.util.List;
    
    public class Bank {
    	
    	private List<Customer> customers; 
    	
    	private Bank() {
    		customers = new ArrayList<Customer>();
    	}
    	
    	private static Bank instance = new Bank();
    	
    	public static Bank getBank(){
    		return instance;
    	}
    	
    	public void addCustomer(String firstName, String lastName){
    		Customer cust = new Customer(firstName, lastName);
    		
    		customers.add(cust);
    	}
    	
    	public int getNumOfCustomers(){
    		return customers.size();
    	}
    	
    	public Customer getCustomer(int index){
    		return customers.get(index);
    	}
    	
    	public Iterator<Customer> getCustomers(){
    		return customers.iterator();
    	}
    }

CustomerReport类：

package com.lukuan.javase.banking;
    
    import java.util.Iterator;
    
    public class CustomerReport {
    
    	public void generateReport() {
    		
    		Bank bank = Bank.getBank();
    		
    		Customer customer = null;
    		
    		System.out.println("\t\t\tCUSTOMERS REPORT");
    		System.out.println("\t\t\t================");
    
    		Iterator<Customer> customers = bank.getCustomers();
    		
    		while(customers.hasNext()){
    		
    //		for (int cust_idx = 0; cust_idx < bank.getNumOfCustomers(); cust_idx++) {
    //			customer = bank.getCustomer(cust_idx);
    
    			customer = customers.next();
    			
    			System.out.println();
    			System.out.println("Customer: " + customer.getLastName() + ", "
    					+ customer.getFirstName());
    
    			Iterator<Account> accounts = customer.getAccounts();
    			
    			while(accounts.hasNext()){
    //			for (int acct_idx = 0; acct_idx < customer.getNumOfAccounts(); acct_idx++) {
    //				Account account = customer.getAccount(acct_idx);
    				
    				Account account = accounts.next();
    				
    				String account_type = "";
    
    				// Determine the account type
    				/***
    				 * Step 1: Use the instanceof operator to test what type of
    				 * account we have and set account_type to an appropriate value,
    				 * such as "Savings Account" or "Checking Account".
    				 ***/
    				if (account instanceof SavingAccount) {
    					account_type = "Savings Account";
    				} else if (account instanceof CheckingAccount) {
    					account_type = "Checking Account";
    				}
    
    				// Print the current balance of the account
    				/***
    				 * Step 2: Print out the type of account and the balance. Feel
    				 * free to use the currency_format formatter to generate a
    				 * "currency string" for the balance.
    				 ***/
    				System.out.println(account_type + ": current balance is ��"
    						+ account.getBalance());
    
    			}
    		}
    
    	}
    
    }

自定义异常类OverdraftException：

package com.lukuan.javase.banking;
    
    public class OverdraftException extends RuntimeException {
    
    	private static final long serialVersionUID = 1L;
    
    	private double deficit;
    	
    	public double getDeficit() {
    		return deficit;
    	}
    	
    	public OverdraftException(String message, double deficit) {
    		super(message);
    		this.deficit = deficit;
    	}
    }

TestBanking8测试类：

package com.lukuan.javase.test;
    
    import com.lukuan.javase.banking.Bank;
    import com.lukuan.javase.banking.CheckingAccount;
    import com.lukuan.javase.banking.Customer;
    import com.lukuan.javase.banking.CustomerReport;
    import com.lukuan.javase.banking.SavingAccount;
    
    public class TestBanking8 {
    
      public static void main(String[] args) {
        Bank     bank = Bank.getBank();
        Customer customer;
        CustomerReport report = new CustomerReport();
    
        // Create several customers and their accounts
        bank.addCustomer("Jane", "Simms");
        customer = bank.getCustomer(0);
        customer.addAccount(new SavingAccount(500.00, 0.05));
        customer.addAccount(new CheckingAccount(200.00, 400.00));
    
        bank.addCustomer("Owen", "Bryant");
        customer = bank.getCustomer(1);
        customer.addAccount(new CheckingAccount(200.00));
    
        bank.addCustomer("Tim", "Soley");
        customer = bank.getCustomer(2);
        customer.addAccount(new SavingAccount(1500.00, 0.05));
        customer.addAccount(new CheckingAccount(200.00));
    
        bank.addCustomer("Maria", "Soley");
        customer = bank.getCustomer(3);
        // Maria and Tim have a shared checking account
        customer.addAccount(bank.getCustomer(2).getAccount(1));
        customer.addAccount(new SavingAccount(150.00, 0.05));
    
        // Generate a report
        report.generateReport();
      }
    }

测试结果：

CUSTOMERS REPORT
    			================
    
    Customer: Simms, Jane
    Savings Account: current balance is ��500.0
    Checking Account: current balance is ��200.0
    
    Customer: Bryant, Owen
    Checking Account: current balance is ��200.0
    
    Customer: Soley, Tim
    Savings Account: current balance is ��1500.0
    Checking Account: current balance is ��200.0
    
    Customer: Soley, Maria
    Checking Account: current balance is ��200.0
    Savings Account: current balance is ��150.0

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