用IO流操作txt文件作为数据库模拟实现一个ATM业务操作系统---->网上银行,实现登录,查询余额,存款,取款,转账,开户,销户等业务功能
1.用户类----->User:
package atm; import java.io.Serializable; public class User implements Serializable{ //建议除了私有属性 无参数有参数构造方法 属性对应的get、set方法 //建议类实现一个序列化接口 添加一个序列化版本号 private static final long serialVersionUID = 1L; //只是为了记录数据库中的一行信息 账号 密码 余额 private String aName; private String aPassword; private Float aSalary; public User() {} public User(String aName,String aPassword,Float aSalary) { this.aName = aName; this.aPassword = aPassword; this.aSalary = aSalary; } public String getaName() { return this.aName; } public void setaName(String newName) { this.aName = newName; } public String getaPassword() { return this.aPassword; } public void setaPassword(String newPassword) { this.aPassword = newPassword; } public Float getSalary() { return this.aSalary; } public void setSalary(Float newSalary) { this.aSalary = newSalary; } }
2.操作IO的类------>FileLoadAndCommit:
package atm; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.util.HashMap; import java.util.Iterator; //操作文件 public class FileLoadAndCommit { //文件路径 private String pathName = null; public FileLoadAndCommit(String pathName) { this.pathName = pathName; } //读取文件装入集合 public HashMap<String,User> loadFile(){ //临时的存储空间,将文件中读取的数据存储以便于修改 HashMap<String,User> userBox = new HashMap<String,User>(); //IO流读取 FileReader fr = null; BufferedReader br = null; try { fr = new FileReader(new File(pathName)); br = new BufferedReader(fr); String code = br.readLine();//读取一行 //循环遍历所有行 按"-"拆分一行的数据,作为User存入集合 while(code != null) { String[] value = code.split("-"); User user = new User(value[0],value[1],Float.parseFloat(value[2])); userBox.put(user.getaName(),user); code = br.readLine(); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally { try { //如果流管道存在,才关闭 if(fr != null) { fr.close(); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { if(br != null) { br.close(); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return userBox; } //将集合更新入文件 public void commit(HashMap<String,User> userBox) { //IO流写入 FileWriter fw = null; BufferedWriter bw = null; try { fw = new FileWriter(new File(pathName)); bw = new BufferedWriter(fw); //迭代集合内所有账户名 按账户名找到对应的User对象 Iterator<String> names = userBox.keySet().iterator(); while(names.hasNext()) { String name = names.next(); User user = userBox.get(name); //用StringBuilder拼接字符串 StringBuilder sBuilder = new StringBuilder(); sBuilder.append(user.getaName()); sBuilder.append("-"); sBuilder.append(user.getaPassword()); sBuilder.append("-"); sBuilder.append(user.getSalary()); bw.write(sBuilder.toString());//将拼好的一行数据写入文件 bw.flush();//刷新 bw.newLine();//换行 } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally { //必须先关闭BufferedWriter再关闭FileWrite,否贼会抛异常java.io.IOException: Stream closed try { if(bw != null) { bw.close(); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { if(fw != null) { fw.close(); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }
3.负责读写的类----->AtmDao:
package atm; import java.util.HashMap; //持久化,负责读写数据,缓存 public class AtmDao { private FileLoadAndCommit flac = new FileLoadAndCommit("D:\\test\\ATM\\testATM.txt"); HashMap<String,User> userBox = flac.loadFile(); //获取一个User对象 public User selectOne(String aName) { return userBox.get(aName); } //更新文件数据 public void update(User user) { userBox.put(user.getaName(),user); flac.commit(userBox); } //删除文件数据 public void delete(User user) { userBox.remove(user.getaName(),user); flac.commit(userBox); } }
4.负责业务逻辑的类------>ATMService:
package atm; import java.util.HashMap; //负责业务逻辑 判断 比较 计算 public class ATMService { //登录 private AtmDao dao = new AtmDao(); public String login(String aName,String aPassword) { User user = dao.selectOne(aName); if(user!=null) { if(aPassword.equals(user.getaPassword())) { return "登录成功"; } } return "用户名或密码错误"; } //查询余额 public Float inquiry(String aName) { User user = dao.selectOne(aName); return user.getSalary(); } //存款 public void addMoney(String aName,Float addMoney) { User user = dao.selectOne(aName);//获取该用户对象 user.setSalary(user.getSalary()+addMoney);//用User的set方法修改用户金额 dao.update(user);//更新文件数据 System.out.println("存款成功\n"); } //取款 public void getMoney(String aName,Float getMoney) { User user = dao.selectOne(aName);//获取该用户对象 if(getMoney <= user.getSalary()) {//如果要取出的钱大于余额就不能取了 user.setSalary(user.getSalary()-getMoney); dao.update(user); System.out.println("取款成功\n"); }else { System.out.println("对不起,您的余额不足\n"); } } //转账 public void transferMoney(String outName,String inName,Float transferMoney) { User outUser = dao.selectOne(outName);//转出用户 User inUser = dao.selectOne(inName);//转入用户 if(inUser!=null) {//转入用户存在 if(outUser!=inUser) {//转出和转入用户不能是同一个用户 if(transferMoney <= outUser.getSalary()) {//转出金额大于余额就不能转了 outUser.setSalary(outUser.getSalary()-transferMoney);//修改转出用户余额 inUser.setSalary(inUser.getSalary()+transferMoney);//修改转入用户余额 //更新文件数据 dao.update(outUser); dao.update(inUser); System.out.println("转账成功\n"); }else { System.out.println("对不起"+outName+",您的余额不足\n"); } }else { System.out.println("对不起,不能给自己转账,您可以试试使用存款业务\n"); } }else { System.out.println("对不起,您输入的用户不存在\n"); } } //开户 public User creatUser(String aName,String aPassword,Float aSalary) { User user = new User(aName,aPassword,aSalary); dao.update(user);//更新文件数据 System.out.println("用户"+aName+",创建成功"); return user; } //销户 public void deleteUser(String aName) { User user = dao.selectOne(aName);//获取名为aName的用户 if(user != null) {//判断该用户是否在文件数据内存在 dao.delete(user); System.out.println("用户"+aName+",删除成功"); }else { System.out.println("要销毁的账户不存在"); } } }
5.测试类----->TestMain:
package atm; import java.util.Scanner; public class TestMain { public static void main(String[] args) { ATMService atmService = new ATMService();//获取执行业务的方法 Scanner input = new Scanner(System.in); System.out.println("欢迎进入ATM机系统"); System.out.println("请选择要操作的业务:\n1.用户登录\n2.开户\n3.按任意键退出"); String choice = input.next(); if(choice.equals("1")) { System.out.println("请输入账户名"); String name = input.next(); System.out.println("请输入密码"); String password = input.next(); String afterLogin = atmService.login(name,password);//判断输入的账户名密码是否正确 if(afterLogin.equals("登录成功")) {//if正确则登录成功 System.out.println("登录成功!\n"); //使用while循环反复进行switch执行操作业务 while(true) { System.out.println("请选择服务项目:"); System.out.println("1.查询\n2.存款\n3.取款\n4.转账\n5.销户\n(按q退出系统)"); String option = input.next(); switch (option) { case "1": //查询 Float money = atmService.inquiry(name); System.out.println("尊敬的客户,您的余额为"+money+"元\n"); break; case "2": //存款 System.out.println("请输入存款金额"); Float addMoney = input.nextFloat(); atmService.addMoney(name,addMoney); break; case "3": //取款 System.out.println("请输入取款金额"); Float getMoney = input.nextFloat(); atmService.getMoney(name,getMoney); break; case "4": //转账 System.out.println("请输入转账用户ID:"); String id = input.next(); System.out.println("请输入转账金额:"); Float transferMoney = input.nextFloat(); atmService.transferMoney(name,id,transferMoney); break; case"5": //销户 System.out.println("您确定要销毁当前账户吗?账户内所有余额都会消失\nYes/No\n"); String decision = input.next(); if(decision.equalsIgnoreCase("yes")) { atmService.deleteUser(name);//删除当前user数据 }else if(decision.equalsIgnoreCase("no")){ break; } break; case "q": System.out.println("已退出ATM机系统,感谢您的使用!!!"); System.exit(0);//退出程序 break; default: System.out.println("请输入正确的指令\n"); break; } } }else { System.out.println(afterLogin); } }else if(choice.equals("2")){ //开户 System.out.println("请设置您的用户名"); String newUserName = input.next(); System.out.println("请设置您的密码"); String newPassword = input.next(); User newUser = atmService.creatUser(newUserName, newPassword, 0.0F); System.out.println("\n初始余额为"+newUser.getSalary()+"元"); }else { System.out.println("已退出ATM机系统,感谢您的使用!!!"); } } }
部分运行结果:
1.账户登录
2.查询
3.存款
4.退出
作为数据库的txt文件:
위 내용은 Java로 ATM 기계 운영 체제를 구현하는 방법의 상세 내용입니다. 자세한 내용은 PHP 중국어 웹사이트의 기타 관련 기사를 참조하세요!