定义一个类实现银行帐户的概念，包括的变量有"帐号"和"存款余额"，包括的方法有"存款"、"取款"和
public class Main {
public static void main(String[] args){
Bank bank = new Bank("HDBank");//创建银行类
bank.openAccount("xiaoming","666",0);//开账户：账号xiaoming，密码666
bank.openAccount("xiaoli","777",0);//开账户
bank.openAccount("xiaohong","888",0);
bank.saveMoney("xiaoli",100);//
//向特定账户存钱
bank.drawMoney("xiaoli",50,"777");
//从特定账户取钱,需验证密码
bank.showAccount("xiaoli");
//显示xiaoli账户信息（用户名，余额）
bank.drawMoney("xiaoli",100,"a wrong password");
//密码错误，取钱失败的情况
bank.drawMoney("xiaoli",100,"777");
//余额不足的情况
}
}
class Account{
private String userName;
private String password;
private double balance;
Account(String userName,String password,double balance){
this.userName = userName;
this.password = password;
this.balance = balance;
}
public void save(double money){
//存钱
balance += money;
System.out.printf("%s存了%.2f元，账户余额为%.2f元。\n",userName,money,balance);
}
public void draw(double money){
//取钱，若账户余额不足，则不能取钱
if(balance - money <= 0) {
System.out.printf("%s取钱%.2f，账户余额为%.2f元。",userName,money,balance);
System.out.println("余额不足，取钱失败。");
}else {
balance -= money;
System.out.printf("%s取了%.2f元，账户余额为%.2f元。\n", userName, money, balance);
}
}
public void show(){
//显示账户信息
System.out.printf("userName:%s\n",userName);
System.out.printf("balance:%.2f\n",balance);
}
public String getUserName(){
//得到用户名
return userName;
}
public String getPassword(){
//得到密码
return password;
}
public String getInfo(){
//返回账户信息
return "userName:"+userName+",banlance:"+balance;
}
}
class Bank{
public String bankName;
private ArrayList<Account> accounts;
Bank(String bankName){
this.bankName=bankName;
accounts=new ArrayList<Account>();
}
Bank(String bankName,ArrayList<Account> accounts){
this.bankName=bankName;
this.accounts=accounts;
}
public void openAccount(String userName,String password,double balance){
//开账户
accounts.add(new Account(userName,password,balance));
}
public Account seekAccount(String userName){
//查找账户按用户名,若找到，返回该账户，否则，返回null
for(Account account:accounts){
if(userName.equals(account.getUserName()))
return account;
}
return null;
}
public void showAccount(String userName){
Account account=seekAccount(userName);
if(account==null)
System.out.println("该账户不存在。");
else
account.show();
}
public void saveMoney(String userName,double money){
//向特定账户存钱
Account account = seekAccount(userName); //查找
if(account==null)
System.out.println("该账户不存在。");
else
account.save(money);
}
public void drawMoney(String userName,double money,String password){
//从特定账户取钱,需验证密码
Account account = seekAccount(userName); //查找
if(account==null)
System.out.println("该账户不存在。");
else {
if(password.equals(account.getPassword())) {
account.draw(money);
}else {
System.out.println("密码不正确，取钱失败。");
}
}
}
}
扩展资料：
思路：
（1）、定义一个账户类，包含用户名、密码、余额等属性、存钱、取钱等方法。
（2）、定义一个银行类，包含银行名、账户列表等属性，开账户、查账户的功能。账户列表可以使用集合相关的类，如ArrayList，最好同时使用泛型。
（3）、定义一个测试类及main函数，在其中创建一个银行，开设一些账号，模拟存钱、取钱、显示余额等。
private String userID；
//默认余额10元
private double balance =10.0；
public void setUserID(Stirng userID) {
this.userID = userID;
}
public int getUserID() {
return userID;
}
public void setBalance(double balance) {
this.balance= balance;
}
public double getBalance() {
return balance;
}
//存款方法
public void deposit(double money){
this.setBalance(this.getBalance()+ money);
System.out.println("你存入的金额为：" +money );
System.out.println("你余额为：" +this.getBalance() );
}
//取款方法
public void draw(double money){
if(money >= this.getBalance() ){
System.out.println("你取出的金额为：" +money );
this.setBalance(this.getBalance()- money);
System.out.println("你余额为：" +this.getBalance() );
}else{
System.out.println("余额不足，取款失败！" );
}
}
//查询方法
public void inquireAbout(){
System.out.println("你余额为：" +this.getBalance() );
}
}
