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@Hubertoo 2017-07-17T05:31:39.000000Z 字数 5815 阅读 794

OOP.Unit05

达内

知识体系

抽象类和接口

使用抽象类

使用接口

多态

  1. Animal a = new Dog();
  3. Dog dog = (Dog) a;
  5. //一定要注意父类继承关系或者接口实现关系，不然会有：ClassCastException
  6. //这个时候就要用到instanceof关键字来判断

定义成员内部类

  1.  //内部类加上外部类
  2. package day02;
  4. public class Outer {
  5.     private int time;
  6.     private Inner inner;
  8.     Outer(int time){
  9.         this.time = time;
  10.         inner = new Inner();
  11.         inner.say();
  12.     }
  14.     public void printTime(){
  15.         System.out.println(time);
  16.     }
  18.     class Inner{
  19.         public void say(){
  20.             time++;
  21.             System.out.println("hahahaha");
  22.         }
  23.     }
  24. }
  26. //测试类
  27. package day02;
  29. public class OuterTest {
  30.     public static void main(String[] args) {
  31.         Outer o = new Outer(100);
  33.         o.printTime();
  34.     }
  35. }
  37. //结果是：
  38. //      hahahaha
  39. //      101

定义匿名内部类

  1.  //定义Action接口
  2. package day02;
  4. public interface Action {
  5.     public void execute();
  6. }
  7.  //匿名内部类
  8.  package day02;
  10. public class Main {
  11.     public static void main(String[] args) {
  12.         Action action = new Action(){
  13.             public void execute(){
  14.                 System.out.println("Hello World");
  15.             }
  16.         };
  17.         action.execute();
  18.     }
  19. }

经典案例

根据周长计算不同形状图形的面积

Shape抽象类

  1. package day02;
  3. public abstract class Shape {
  4.     protected double c;
  6.     public abstract double area();
  7. }

Circle类

  1. package day02;
  3. public class Circle extends Shape{
  4.     public Circle(double c){
  5.         this.c = c;
  6.     }
  8.     /**
  9.      * 计算圆形的面积
  10.      */
  12.     public double area(){
  13.         return 0.0625*c*c;
  14.     }
  15. }

Square类

  1. package day02;
  3. public class Square extends Shape {
  4.     public Square(double c){
  5.         this.c = c;
  6.     }
  8.     /**
  9.      * 计算圆形的面积
  10.      */
  12.     public double area(){
  13.         return 0.0725*c*c;
  14.     }
  15. }

TestShape类

  1. package day02;
  3. public class TestShape {
  4.     public static void main(String[] args) {
  5.         Shape[] shapes = new Shape[2];
  6.         shapes[0] = new Circle(4);
  7.         shapes[1] = new Square(4);
  9.         System.out.println(shapes[0].area());
  10.         System.out.println(shapes[1].area());
  11.     }
  12. }
  13. // 运行结果是：1.0   1.16

银行卡系统（实现银联接口）

  1. 银联接口描述统一制定的规则，该接口提供检测密码方法，取钱方法，查询余额方法
  2. 工商银行接口，用来描述工银行发卡的功能，在满足银联接口的基础上，增加在线支付功能
  3. 农行接口，另外增加支付电话费的问题，卡内余额可以透支2000.
  4. 实现两个接口并测试

银联接口

  1. package day02;
  3. public interface UnionPay {
  4.     //查看余额
  5.     public double getBalance();
  7.     //取钱
  8.     public boolean drawMoney(double number);
  10.     //检查密码
  11.     public boolean checkPwd(String input);
  13. }

工行接口

  1. package day02;
  3. public interface ICBC extends UnionPay {
  4.     //增加在线支付功能
  5.     public void payOnline(double number);
  6. }

农行接口

  1. package day02;
  3. public interface ABC extends UnionPay{
  4.     //增加支付电话费的功能
  5.     public boolean payTelBill(String phoneNum, double sum);
  6. }

工行实现类

  1. package day02;
  3. public class ICBCImpl implements ICBC {
  4.     private double money;
  5.     private String pwd;
  9.     public ICBCImpl(double money, String pwd) {
  10.         super();
  11.         this.money = money;
  12.         this.pwd = pwd;
  13.     }
  14.     @Override
  15.     public double getBalance() {
  16.         return money;
  17.     }
  18.     @Override
  19.     public boolean drawMoney(double number) {
  20.         if(number <= money){
  21.             money -= number;
  22.             return true;
  23.         }
  24.         return false;
  25.     }
  26.     @Override
  27.     public boolean checkPwd(String input) {
  28.         if(pwd.equals(input)){
  29.             return true;
  30.         }
  31.         return false;
  32.     }
  33.     @Override
  34.     public void payOnline(double number) {
  35.         if(number < money){
  36.             money -= number;
  37.         }
  39.     }
  42. }

农行实现类

  1. package day02;
  3. public class ABCImpl implements ABC{
  4.     //卡内余额，允许透支2000
  5.     private double balance;
  6.     //帐号密码
  7.     private String password;
  9.     public ABCImpl(double balance, String password) {
  10.         super();
  11.         this.balance = balance;
  12.         this.password = password;
  13.     }
  15.     @Override
  16.     public double getBalance() {
  17.         // TODO Auto-generated method stub
  18.         return balance;
  19.     }
  21.     @Override
  22.     public boolean drawMoney(double number) {
  23.         if(number <= (balance - 2000)){
  24.             balance -= number;
  25.             return true;
  26.         }
  27.         return false;
  28.     }
  30.     @Override
  31.     public boolean checkPwd(String input) {
  32.         if(password.equals(input)){
  33.             return true;
  34.         }
  35.         return false;
  36.     }
  38.     @Override
  39.     public boolean payTelBill(String phoneNum, double sum) {
  40.         if(phoneNum.length() == 11 && (balance-sum >= -2000)){
  41.             balance -= sum;
  42.             return true;
  43.         }
  44.         return false;
  45.     }
  48. }

工行测试类

  1. package day02;
  3. import java.util.Scanner;
  5. public class UnionPayTest {
  6.     public static void main(String[] args) {
  7.         UnionPay icbc = new ICBCImpl(2000,"123456");
  9.         Scanner input = new Scanner(System.in);
  10.         System.out.println("输入密码：");
  11.         if(icbc.checkPwd(input.next())){
  12.             System.out.println("请输入金额：");
  13.             double num = Double.parseDouble(input.next());
  14.             if(icbc.drawMoney(num)){
  15.                 System.out.println("取钱成功，卡余额为：" + icbc.getBalance());
  16.             }else{
  17.                 System.out.println("取钱失败");
  18.             }
  19.         }else{
  20.             System.out.println("密码错误");
  21.         }
  23.         input.close();
  24.     }
  25. }

ATM机系统
ABCATM类

  1. package day02;
  3. import java.util.Scanner;
  5. /**
  6.  * 用来描述插入银行卡后的操作
  7.  * 
  8.  * @author zeyan
  9.  *
  10.  */
  11. public class ABCATM {
  12.     private UnionPay card;
  14.     public void insertCard(UnionPay userCard){
  15.         if(card == null){
  16.             card = userCard;
  17.         }
  18.     }
  20.     private void outCard(){
  21.         card = null;
  22.     }
  24.     private void showBalance(){
  25.         System.out.println("当前余额是：" + card.getBalance());
  26.     }
  28.     private void takeMoney(){
  29.         Scanner input = new Scanner(System.in);
  30.         System.out.println("输入取款金额：");
  31.         double number = Double.parseDouble(input.next());
  32.         if(card.drawMoney(number)){
  33.             System.out.println("取款成功");
  34.         }else{
  35.             System.out.println("取款失败");
  36.         }
  37.     }
  39.     private void payTelBill(){
  40.         Scanner input = new Scanner(System.in);
  41.         if(card instanceof ABC){
  42.             ABC  abcCard = (ABC) card;
  43.             System.out.println("请输入电话号码：");
  44.             String telNum = input.next();
  45.             System.out.println("请输入缴费额：");
  46.             double sum = Double.parseDouble(input.next());
  48.             if(abcCard.payTelBill(telNum, sum)){
  49.                 System.out.println("缴费成功");
  50.             }else{
  51.                 System.out.println("缴费失败");
  52.             }
  53.         }else{
  54.             System.out.println("你的卡不是农行卡");
  55.         }
  56.     }
  58.     public void allMenu(){
  59.         Scanner input = new Scanner(System.in);
  61.         System.out.println("请输入密码：");
  62.         String pwd = input.next();
  64.         if(card.checkPwd(pwd)){
  65.             System.out.println("请选择功能： \n 1.查看余额    2.取款   3.缴电话费");
  66.             int choice = Integer.parseInt(input.next());
  67.             switch(choice){
  68.             case 1:
  69.                 showBalance();
  70.                 break;
  71.             case 2:
  72.                 takeMoney();
  73.                 break;
  74.             case 3:
  75.                 payTelBill();
  76.                 break;
  77.                 default:
  78.                     System.out.println("非法输入");
  79.             }
  80.         }else{
  81.             System.out.println("密码错误");
  82.         }
  83.         this.outCard();
  84.     }
  85. }

ATMTest类

  1. package day02;
  3. public class ATMTest {
  4.     public static void main(String[] args) {
  5.         ABCATM atm = new ABCATM();
  7.         ABCImpl abc = new ABCImpl(1000, "123456");
  9.         atm.insertCard(abc);
  10.         atm.allMenu();
  12.     }
  13. }

课后作业

笔记

实现射击游戏

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