例：
ATM机的程序实现
ATM机主程序：
package com.lovo.bean; import java.util.Scanner; public class ATMMachine { private UserInf [] allUsers = new UserInf [5]; private int cash = 200000; public final int MAX_CASH = 1000000; UserInf theUser = new UserInf(); public ATMMachine(){ this.allUsers[0] = new UserInf("1224059","asw234",10000); this.allUsers[1] = new UserInf("1224060","asw345",10000); this.allUsers[2] = new UserInf("1224061","asw456",10000); this.allUsers[3] = new UserInf("1224062","asw567",10000); this.allUsers[4] = new UserInf("1224063","asw678",10000); } //运行 public void run(){ this.welcome(); boolean flag = this.login(); if(flag){ while(true){ int choice = this.chooseMenu(); switch (choice) { case 1: this.qurey(); break; case 2: this.storeMoney(); break; case 3: this.getMoney(); break; case 4: this.bankTransfer(); break; case 5: this.changePwd(); break; case 6: this.login(); break; case 7: this.exit(); break; default: System.out.println("输入错误！"); break; } } }else { System.out.println("您的卡被没收，请带上有效证件到前台处理！"); } } //欢迎界面 private void welcome(){ System.out.println("***欢迎光临！***"); } //登录 private boolean login(){ Scanner scan = new Scanner(System.in); for (int i = 0; i < 3; i++) { System.out.println("请输入您的卡号："); String inputCardNum = scan.next(); System.out.println("请输入您的密码："); String inputPwd = scan.next(); for (int j = 0; j < this.allUsers.length; j++) { if(inputCardNum.equals(this.allUsers[j].getCardNum()) && inputPwd.equals(this.allUsers[j].getPassword())){ System.out.println("登录成功！"); this.theUser = this.allUsers[j]; return true; } } System.out.println("卡号或密码错误，您还有"+(2-i)+"请重新输入！"); } return false; } //选择菜单 private int chooseMenu(){ Scanner scan = new Scanner(System.in); System.out.println("1: 查询余额"); System.out.println("2: 存款"); System.out.println("3: 取款"); System.out.println("4: 转账"); System.out.println("5: 修改密码"); System.out.println("6: 退出，重新登录"); System.out.println("7: 退出系统"); System.out.println("请输入您的操作："); int a = scan.nextInt(); return a; } //查询余额 private void qurey(){ System.out.println("您的余额为："+theUser.getAccount()); } //存款 private void storeMoney(){ Scanner scan = new Scanner(System.in); System.out.println("请放入金额"); int inputMoney = scan.nextInt(); if(inputMoney > 0 && inputMoney % 100 == 0){ if((inputMoney + this.cash) <= this.MAX_CASH){ this.cash = this.cash + inputMoney; theUser.setAccount(theUser.getAccount()+inputMoney); System.out.println("存款成功！"); }else{ System.out.println("金额太大，无法存储，请到前台存储！"); } }else{ System.out.println("放入金额中有非100元人民币的钞票，无法存储，请到前台办理！"); } } //取款 private void getMoney(){ Scanner scan = new Scanner(System.in); System.out.println("请输入要取的金额："); int inputGetMoney = scan.nextInt(); if(inputGetMoney > 0 && inputGetMoney % 100 == 0){ if(inputGetMoney <= this.cash){ if(inputGetMoney <= theUser.getAccount()){ theUser.setAccount(theUser.getAccount() - inputGetMoney); this.cash = this.cash - inputGetMoney; System.out.println("取款成功！"); }else{ System.out.println("您的余额已不足！"); } }else { System.out.println("超出最大取款值，无法取出，请重新输入！"); } } else{ System.out.println("输入金额不是100的倍数，无法取出，请重新输入！"); } } //转账 private void bankTransfer(){ Scanner scan = new Scanner(System.in); System.out.println("输入要转入的账户"); String inputCardNum = scan.next(); boolean flag = false; for (int i = 0; i < allUsers.length; i++) { if(!(inputCardNum.equals(theUser.getCardNum())) && inputCardNum.equals(allUsers[i].getCardNum())){ System.out.println("输入要转账的金额"); int money = scan.nextInt(); if(money < 0){ System.out.println("您输入的金额为负数，输入有误，请重新输入！"); }else if(money > this.theUser.getAccount()){ System.out.println("您的余额不足，转账失败！"); }else { theUser.setAccount((theUser.getAccount() - money)); allUsers[i].setAccount(allUsers[i].getAccount() + money); System.out.println("转账成功！"); return; } } } if(flag){ System.out.println("找不到你要转入的账户，请重新操作！"); } } //修改密码 private void changePwd(){ Scanner scan = new Scanner(System.in); System.out.println("请输入新密码："); String passWord = scan.next(); theUser.setPassword(passWord); System.out.println("修改成功,请重新登录！"); login(); } //退出 private void exit(){ System.exit(-1); } }
/*
定义一个用户类
*/
package com.lovo.bean; public class UserInf { private String cardNum; private String password; private double account; public UserInf(){ } public UserInf(String cardNum, String password, double account) { this.cardNum = cardNum; this.password = password; this.account = account; } public String getCardNum() { return cardNum; } public void setCardNum(String cardNum) { this.cardNum = cardNum; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public double getAccount() { return account; } public void setAccount(double account) { this.account = account; } }
实现：
package com.lovo.test;
import com.lovo.bean.ATMMachine;
public class TestMain {
public static void main(String[] args) {
ATMMachine atm = new ATMMachine();
atm.run();
}
}