实训篇:第十一天

设计抽象类Door，它拥有所有门的共性方法open ()和close ()。设计防火接口FireSafe，该接口有一个抽象方法fireProof()。设计防弹接口BulletSafe，该接口有一个抽象方法bulletProof()。综合利用继承、抽象类、接口的知识设计出防火门FireProofDoor和防弹门BulletProofDoor两个类。设计Test类的main()方法，分别调用FireProofDoor和BulletProofDoor的所有方法。（实现各方法时做简单的打印即可）

package ch06_homework4_3;

public abstract class Door {
    public abstract void open();
    public abstract void close();
}

package ch06_homework4_3;

public interface BulletSafe {
    public abstract  void bulletProof();
}

package ch06_homework4_3;

public interface FireSafe{
    public abstract void fireProof();
}

 

package ch06_homework4_3;

public class FireProofDoor extends Door implements  FireSafe {

    @Override
    public void open() {
        System.out.println("FireProofDoor open");
    }

    @Override
    public void close() {
        System.out.println("FireProofDoor close");
    }

    @Override
    public void fireProof() {
        System.out.println("this is a FireProofDoor");
    }
}

package ch06_homework4_3;

public class BulletProofDoor extends Door implements BulletSafe {
    @Override
    public void open() {
        System.out.println("BulletProofDoor open");
    }

    @Override
    public void close() {
        System.out.println("BulletProofDoor close");
    }

    @Override
    public void bulletProof() {
        System.out.println("this is a BulletProofDoor");
    }
}

package ch06_homework4_3;

public class practice8 {
    public static void main(String[] args) {
        Door d1 = new FireProofDoor();
        Door d2 = new BulletProofDoor();

        FireProofDoor f = (FireProofDoor) d1;
        BulletProofDoor b = (BulletProofDoor) d2;

        f.fireProof();
        f.open();
        f.close();

        b.bulletProof();
        b.open();
        b.close();
    }
}

---

1定义一个抽象类Role，有姓名、年龄、性别等成员变量，要求：

• 尽可能隐藏所有变量，再通过GetXXX()和SetXXX()方法对各变量进行读写；
• 至少定义两个构造方法（一个无参的构造方法，一个有参的构造方法，有参的构造方法需要显示调用无参的构造方法）；
• Role类中要体现出this的几种用法。
• 具有一个抽象的无返回值的play()方法；
• 具有一个普通的say()方法；
• 提供一个final sing()方法。
• 各方法中适当地添加打印语句，标识出所在类和所在方法即可。

2从Role类派生出Employee类，要求：

• 增加一个final成员变量id 
• 增加一个静态成员变量company；
• 增加了普通成员变量salary；
• 通过GetXXX()和SetXXX()方法对新增加的变量进行读写；
• 要有至少两个构造方法（一个构造方法只有一个参数id并调用父类无参的构造方法，另一个构造方法有多个属性值做参数并调用父类有参的构造方法）；
• 要体现出this和super的用法；
• 要覆盖play()方法，并在play方法中调用父类的say()方法；
• 各方法中适当地添加打印语句，标识出所在类和所在方法即可。

3在Test类的main()方法中：

• 为Employee中的company赋值；
• 调用Employee的两个构造方法实例化两个对象e1和e2
• 分别打印e1和e2的属性信息
• 调用e1的play方法
• 调用e1的sing方法

注意的地方:

final可以用来修饰抽象类的普通方法，但不能修饰abstract方法

final变量如果没有赋初值是可以之后赋一次值的，之后再次改变就不允许了

package ch06_homework4_4;

public abstract class Role {
    private String name;
    private String age;
    private String gender;

    public Role() {
    }

    public Role(String name, String age, String gender) {
        this();
        this.name = name;
        this.age = age;
        this.gender = gender;
    }

    public String getName() {
        return name;
    }

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

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

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

    @Override
    public String toString() {
        return  "name='" + name + '\'' +
                ", age='" + age + '\'' +
                ", gender='" + gender + '\''
                ;
    }

    public final void sing() {
        System.out.println("role sing");
    }
    public abstract void play();
}

package ch06_homework4_4;

public class Employee extends Role{
    private final String id;
    private static String company;
    private String salary;

    public Employee(String id) {
        super();
        this.id = id;
    }

    public Employee(String name, String age, String gender, String id, String salary) {
        super(name, age, gender);
        this.id = id;
        this.salary = salary;
    }

    @Override
    public void play() {
        System.out.println("employee play");
    }

    public static String getCompany() {
        return company;
    }

    public static void setCompany(String company) {
        Employee.company = company;
    }

    public String getSalary() {
        return salary;
    }

    public void setSalary(String salary) {
        this.salary = salary;
    }

    @Override
    public String toString() {
        return "Employee{" +
                "id='" + id + '\'' +
                ", salary='" + salary + '\'' +
                ", company='" + Employee.getCompany() + "\', " +
                super.toString()+
                '}';
    }
}

package ch06_homework4_4;

public class Test {
    public static void main(String[] args) {
        Employee.setCompany("abc");
        Employee e1 = new Employee("Tom", "12", "male", "1", "0");
        Employee e2 = new Employee("Jerry", "12", "male", "2", "0");

        System.out.println(e1.toString());
        System.out.println(e2.toString());

        e1.play();
        e2.sing();

    }

}