AH.: JAVA SL-110

// Date:2015/08/16
// test_0816_1.java
// 以父類別變數存取子類別物件成員

class Circle{
        protected double radius;

        Circle(double radius){
                this.radius = radius;
        }

        void show(){
                System.out.println("area = " + radius*radius);
        }
}

class App extends Circle{
        private int value;
        App(double r, int v){
                super(r);
                value =  v;
        }

        void show(){
 // 要使用 super，才能印出 Circle.show()
                super.show();   
                System.out.println("radius = " + radius + ", value = " + value);
        }
}

public class test_0816_1{
        public static void main(String args[]){
                Circle a = new App(0.2,3);
                a.show();       //發生 override，只會印 App.show()
        }
}

// Date:2015/08/16
// Demo.java
// 繼承、多型、轉型練習

class Father{
        String name = "Father";
        String getName(){
                return name;
        }
        String greeting(){
                return "Class Father";
        }
}

class Son extends Father{
        String name = "Son";
        String greeting(){
                return "Class Son";
        }
        void foo(){
                System.out.println(name);                       //Son
                System.out.println(this.name);                  //Son
                System.out.println(super.name);                 //Father
                System.out.println(((Son)this).name);           //Son
                System.out.println(((Father)this).name);        //Father
                System.out.println(((Son)this).greeting());     //Class Son
                System.out.println(((Father)this).greeting());  //Class Son
                System.out.println(super.greeting());           //Class Father
        }
}

public class Demo{
        public static void main(String args[]){
                new Son().foo();
        }
}

首先要先建立 RPG 資料夾，裏面要有(Role.java、Swordman.java、Magician.java、RPG.java)

~$  mkdir RPG
~$  cd RPG/

// Role.java
public class Role{
        protected String name;
        protected int level;
        protected int blood;

        //name
        public void setName(String name){
                this.name = name;
        }
        public String getName(){
                return name;
        }

        //level
        public void setLevel(int level){
                this.level = level;
        }
        public int getLevel(){
                return level;
        }

        //blood
        public void setBlood(int blood){
                this.blood = blood;
        }
        public int getBlood(){
                return blood;
        }

        public String toString(){
                return String.format("(%s, %d, %d)%n", this.name, this.level, this.blood);
        }

        public void fight(){}


}

// Swordman.java
class Swordman extends Role{
        public void fight(){
                System.out.println("揮劍攻擊");
        }
}

//Magician.java
class Magician extends Role{
        public void fight(){
                System.out.println("魔法攻擊");
        }
        public void cure(){
                System.out.println("魔法治療");
        }
}

// Date:2015/08/16
// RJG.java(Role.java, Magician.java, Swordman.java)

public class RPG{
        public static void showBlood(Swordman swordman){
                System.out.printf("%s 血量 %d %n", swordman.getName(), swordman.getBlood());
        }

        public static void showBlood(Magician magician){
                System.out.printf("%s 血量 %d %n", magician.getName(), magician.getBlood());
        }


 public static void main(String args[]){
        Swordman swordMan = new Swordman();
        swordMan.setName("Justin");
        swordMan.setLevel(1);
        swordMan.setBlood(200);
        //System.out.println(swordMan.toString());
        System.out.printf("劍士:(%s %d %d)%n", swordMan.getName(), swordMan.getLevel(), swordMan.getBlood());

        Magician magician = new Magician();
        magician.setName("Monica");
        magician.setLevel(1);
        magician.setBlood(100);
        //System.out.println(magician.toString());
        System.out.printf("魔法師:(%s %d %d)%n", magician.getName(),magician.getLevel(), magician.getBlood());

        showBlood(swordMan);
        showBlood(magician);
 }

}

/*------------------------------------------------------------------------------------------------------*/
．is-a 是一個，是一種上下的關係，利用 extends 來實作延伸類別。
．has-a 有一個，是一種聚合的關係，表示類別的成員變數。

class machine{

}
// is-a 電腦類別繼承電子機械產品類別
class computer extends machine{
CPU theCpu;
RAM theRam;
HD TheHd;
}
/*-----------------------------------------------------------------------------------------------------*/
．interface
介面介面也是類別的一種，它是用戶端的程式碼，與類別之間的溝通管道，利用相同的介面可讓程式有一定的規範可循，介面類別完成後就不允許更改。
(主要做用為解決 extends 單一繼承問題)

．宣告
存取權限 interface 介面名稱[]
存取權限 interface 介面名稱 extends //可以讓範圍更大

※
1. 介面的屬性宣告時一定要給定初始值。
2. compile 值，屬性會自動加上 public static final，方法會自動加上 public abstract。
3. 利用 implements 關鍵字來實作 interface。
4. interface 的方法皆為實作區塊，所以當 implements 時，都一定要將其方法加以實作。

class 類別名稱 implements 介面名稱
/*----------------------------------------------------------------------------------------------------*/

．final 修飾字

類別加上 final 不可以被繼承。
方法加上 final 不可以被 override。
屬性加上 final 不可以放更改。

/*----------------------------------------------------------------------------------------------------*/

// 練習 interface 及 implements

interface Pet{
        String name="cute";
        void move();
        void skill();
}

public class Dog implements Pet{
        // 存取權限一定要大於 interface
        public void move(){
                System.out.println("移動");
        }

        public void skill(){
                System.out.println("跑跳");
        }

        public static void main(String args[]){
                Dog d = new Dog();
                d.skill();
                d.move();
        }
}

/*----------------------------------------------------------------------------------------------------*/

※練習 implement 及 extends ，建立檔案：
1. Swimmer.java //interface
2. Flyer.java //interface
3. Driver.java //interface
4. Fish.java //父類別實作 Swimmer
5. Airplane.java //父類別實作 Flyer
6. Boat.java //父類別實作 Swimmer
7. Human.java //父類別
8. Helicopter.java //繼承 Airplane
9. SeaPlan.java //繼承 Airplane 實作 Swimmer
10. Shark.java //繼承 Fish
11. Anemonefish.java //繼承 Fish
12. Piranha.java //繼承 Fish
13. FlyingFish.java //繼承 Fish 實作 Flyer
14. SwimPlayer.java //繼承 Human 實作 Swimmer
15. DemoOcean.java //主程式

首先先建立 Ocean 資料夾，在建立以上檔案。

~$  mkdir Ocean
~$  cd Ocean/

//1. Swimmer.java
interface Swimmer{
      void swim();
}

//2. Flyer.java
interface Flyer{
        void fly();
}

//3. Driver.java
interface Driver extends Swimmer{
     void drive();
}

//4. Fish.java
public class Fish implements Swimmer{
        protected String name;
        public Fish(String name){
                this.name = name;
        }

        public String getName(){
                return name;
        }

        public void swim(){}
}

//5. Airplane.java
public class Airplane implements Flyer{
        protected String name;
        Airplane(String name){
                this.name = name;
        }
        public void fly(){
                System.out.printf("飛機 %s 在飛%n", name);
        }
}

//6. Boat.java
public class Boat implements Swimmer{
        protected String name;
        Boat(String name){
                this.name = name;
        }
        public void swim(){
                System.out.printf("%s 小船在水面航行%n", name);
        }
}

//7. Human.java
public class Human{
        protected String name;
        public Human(String name){
                this.name = name;
        }
        public String getName(){
                return name;
        }
        public void swim(){}
}

//8. Helicopter.java
public class Helicopter extends Airplane{
        Helicopter(String name){
                super(name);
        }

        public void fly(){
                System.out.printf("直升機 %s 在飛%n", name);
        }
}

//9. SeaPlan.java
public class SeaPlan extends Airplane implements Swimmer{
        SeaPlan(String name){
                super(name);
        }

        public void fly(){
                System.out.printf("海上飛機 %s 空中飛行%n", name);
        }

        public void swim(){
                System.out.printf("海上飛機 %s 水面划行%n", name);
        }
}

//10. Shark.java
public class Shark extends Fish{
        Shark(String name){
                super(name);
        }

        public void swim(){
                System.out.printf("鯊魚 %s 游泳 %n", name);
        }
}

//11. Anemonefish.java
public class Anemonefish extends Fish{
        Anemonefish(String name){
                super(name);
        }

        public void swim(){
                System.out.printf("小丑魚 %s 游泳 %n", name);
        }
}

//12. Piranha.java
public class Piranha extends Fish{
        Piranha(String name){
                super(name);
        }

        public void swim(){
                System.out.printf("食人魚 %s 游泳 %n", name);
        }
}

//13. FlyingFish.java
public class FlyingFish extends Fish implements Flyer{
        FlyingFish(String name){
                super(name);
        }

        public void swim(){
                System.out.printf("飛魚 %s 游泳%n", name);
        }
        public void fly(){
                System.out.printf("飛魚 %s 會飛%n",name);
        }
}

//14. SwimPlayer.java
public class SwimPlayer extends Human implements Swimmer{
        SwimPlayer(String name){
                super(name);
        }

        public void swim(){
                System.out.printf("潛水夫 %s 在游泳%n", name);
        }
}

//15. DemoOcean.java  //主程式
public class DemoOcean{
        public static void doSwim(Swimmer swimmer){
                swimmer.swim();
        }

        public static void doFly(Flyer flyer){
                flyer.fly();
        }

        public static void doDriver(Driver driver){
                driver.drive();
        }

        public static void main(String args[]){
        SeaPlan s = new SeaPlan("S");
        FlyingFish f = new FlyingFish("f");
       
        //Swimmer
        doSwim(new Anemonefish("anemonefish"));
        doSwim(new Shark("shark"));
        doSwim(new Piranha("piranha"));
        doSwim(new SwimPlayer("swimmer"));
        doSwim(s);
        doSwim(f);

        //Flyer
        doFly(new Helicopter("helicopter"));
        doFly(s);
        doFly(f);

        }
}

練習 interface method()

// 練習 interface method()
// Service.java

interface Other{
        void execute();
        void doOther();
}

interface Some{
        void execute();
        void doSome();
}

public class Service implements Some,Other{

        public void execute(){
                System.out.println("execute");
        }

        public void doSome(){
                System.out.println("doSome");
        }

        public void doOther(){
                System.out.println("doOther");
        }

        public static void main(String args[]){
                Service d = new Service();
                d.execute();
                d.doSome();
                d.doOther();
        }
}

AH.

2015年8月16日星期日

JAVA SL-110_08/16

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張貼留言

2015年8月16日 星期日

JAVA SL-110_08/16

沒有留言:

張貼留言

2015年8月16日星期日