源代码：

import java.util.Scanner;

interface fangfa{

public void show();

public void qukuan();

public void cunkuan();

public void zhuanzhang();

public void setAcount(String string, String string2, String string3, String string4, double i);

public String getMima();

}

class atm implements fangfa{

String kahao; //私有变量

String name;

String riqi;

double yue;

String mima;

public atm(){ //无参构造函数

}

public atm(String kahao,String name,String riqi,String mima,double yue){ //有参构造函数

this.kahao=kahao;

this.name=name;

this.riqi=riqi;

this.mima=mima;

this.yue=yue;

}

public void setAcount(String kahao,String name,String riqi,String mima,double yue){ //赋值

this.kahao=kahao;

this.name=name;

this.riqi=riqi;

this.mima=mima;

this.yue=yue;

}

public String getkahao(){ return kahao;}//获得值

public String getName(){return name;}

public String getRiqi(){return riqi;}

public String getMima(){return mima;}

public double getYue(){return yue;}

public void show()

{

System.out.println("余额为："+yue);

}

public void cunkuan(){

System.out.println("请输入存款金额:");

Scanner s=new Scanner(System.in);

yue+=s.nextDouble();

show();

}

public void zhuanzhang()

{

atm q=new atm();

Scanner s=new Scanner(System.in);

System.out.println("请输入对方卡号:");

q.kahao=s.nextLine();

System.out.println("请输入转账金额:");

double zhuan=s.nextDouble();

yue=yue-zhuan;

q.yue=q.yue+zhuan;

show();

}

public void qukuan(){

boolean f=true;

while(f){

System.out.println("1、100元");

System.out.println("2、500元");

System.out.println("3、1000元");

System.out.println("4、1500元");

System.out.println("5、2000元");

System.out.println("6、5000元");

System.out.println("7、其他金额");

System.out.println("8、退卡");

System.out.println("9、返回");

System.out.println("请选择");

Scanner s=new Scanner(System.in);

int ch=s.nextInt();

switch(ch){

case 1:

yue=yue-100;

show();

break;

case 2:

yue=yue-500;

show();

break;

case 3:

yue=yue-1000;

show();

break;

case 4:

yue=yue-1500;

show();

break;

case 5:

yue=yue-2000;

show();

break;

case 6:

yue=yue-5000;

show();

break;

case 7:

System.out.println("请输入取款金额：");

double qu=s.nextDouble();

yue=yue-qu;

show();

break;

case 8:

f=false;

break;

case 9:

f=false;

break;

}

}

}

}

public class ABC {

public static void main(String[] args) {

// TODO Auto-generated method stub

fangfa a=new atm();

a.setAcount("111111111111", "nasdf", "199508030048", "123456", 20000);

System.out.println("请输入密码：");

Scanner aa=new Scanner(System.in);

String ba=aa.nextLine();

if(ba.equals(a.getMima()))

while(true){

System.out.println("1、取款");

System.out.println("2、存款");

System.out.println("3、转账");

System.out.println("4、查询");

System.out.println("请选择：");

Scanner s=new Scanner(System.in);

int b=s.nextInt();

switch(b){

case 1:

a.qukuan();

break;

case 2:

a.cunkuan();

break;

case 3:

a.zhuanzhang();

break;

case 4:

a.show();

}

}

}

}

实验截图：