继承

封装的知识点基本结束了，现在开始学习继承（extends），留下今天学习足迹：

public class ATM {

public Properties pro=new Properties();

public User currentUser;

public ATM(){

try{

pro.load(new FileReader("src\\com\\lovo\\atmTest\\bank.txt"));

}catch(Exception e){

System.out.print("文件未找到");

}

currentUser=login();

if(currentUser==null){

JOptionPane.showMessageDialog(null, "非法用户");

System.exit(0);

}

while(true){

String x=JOptionPane.showInputDialog(null,"1、存款\n2、取款\n3、查询余额\n4、转账\n5、改密\n6、取卡\n请选择：\n");

int item=Integer.parseInt(x);

switch(item){

case 1:

saveMoney();

break;

case 2:

getMoney();

break;

case 3:

showMoney();

break;

case 4:

changeMoney();

break;

case 5:

changePwd();

break;

case 6:

JOptionPane.showMessageDialog(null, "谢谢使用");

System.exit(0);

break;

default:

JOptionPane.showMessageDialog(null, "请输入1--6");

break;

}

}

}

/**

* 改密

*/

public void changePwd() {

String oldPwd=JOptionPane.showInputDialog(null,"请输入原密码");

if(oldPwd.equals(currentUser.pwd)==false){

JOptionPane.showMessageDialog(null, "原密码错误");

return;

}

String newPwd=JOptionPane.showInputDialog(null,"请输入新密码");

String rePwd=JOptionPane.showInputDialog(null,"请重新输入密码");

if(rePwd.equals(newPwd)==false){

JOptionPane.showMessageDialog(null, "两次密码不一致");

return;

}

currentUser.pwd=newPwd;

pro.setProperty(currentUser.code+".pwd", newPwd+"");

saveFile();

JOptionPane.showMessageDialog(null, "改密成功，请重新登录");

login();

}

/**

* 转账

*/

public void changeMoney() {

String code=JOptionPane.showInputDialog("请输入转账账户");

String a=pro.getProperty(code+".money");

if(a==null){

JOptionPane.showMessageDialog(null, "账户错误");

return;

}

String m=JOptionPane.showInputDialog("请输入转账金额");

int mm=Integer.parseInt(m);

if(mm>currentUser.money){

JOptionPane.showMessageDialog(null, "账户余额不足");

return;

}

currentUser.money-=mm;

int aa=Integer.parseInt(a);

aa+=mm;

pro.setProperty(currentUser.code+".money", currentUser.money+"");

pro.setProperty(code+".money", aa+"");

saveFile();

showMoney();

}

/**

* 显示余额

*/

public void showMoney() {

String money=pro.getProperty(currentUser.code+".money");

JOptionPane.showMessageDialog(null,"账户余额为："+Integer.parseInt(money));

}

/**

* 取钱

*/

public void getMoney() {

String m=JOptionPane.showInputDialog("请输入取款金额");

int mm=Integer.parseInt(m);

if(mm>currentUser.money){

JOptionPane.showMessageDialog(null, "账户余额不足");

}

currentUser.money-=mm;

pro.setProperty(currentUser.code+".money", currentUser.money+"");

saveFile();

showMoney();

}

/**

* 存钱

*/

public void saveMoney() {

String m=JOptionPane.showInputDialog("请输入存款金额");

int mm=Integer.parseInt(m);

currentUser.money+=mm;

pro.setProperty(currentUser.code+".money", currentUser.money+"");

saveFile();

showMoney();

}

/**

* 存款

*/

public void saveFile(){

try{

pro.store(new FileWriter("src\\com\\lovo\\atmTest\\bank.txt"),null);

}catch(Exception e){

System.out.print("文件未找到");

}

}

/**

* 登录

* @return 登录状况，如果失败，返回null

*/

public User login(){

for(int i=0;i<3;i++){

String userCode=JOptionPane.showInputDialog(null,"请输入帐号");

String userPwd=JOptionPane.showInputDialog(null,"请输入密码");

String p=pro.getProperty(userCode+".pwd");

if(userPwd.equals(p)){

JOptionPane.showMessageDialog(null, "登陆成功");

User u=new User();

u.code=userCode;

u.pwd=userPwd;

u.money=Integer.parseInt(pro.getProperty(userCode+".money"));

return u;

}

JOptionPane.showMessageDialog(null, "帐号或密码错误");

}

return null;

}

}