이것이자바다 8장 확인문제

3번

package eightInterface;

public interface Soundable {
	String sound();
}

package eightInterface;

public class Cat1 implements Soundable{

	@Override
	public String sound() {
		// TODO Auto-generated method stub
		return "야옹";
	}

}

package eightInterface;

public class Dog1 implements Soundable{

	@Override
	public String sound() {
		// TODO Auto-generated method stub
		return "멍멍";
	}
}

package eightInterface;

public class SoundableExample {

	private static void printSound(Soundable soundable) {
		System.out.println(soundable.sound());
	}
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		printSound(new Cat1());
		printSound(new Dog1());
	}

}

 

4번

package eightInterface;

public class MySqlDao implements DataAccessObject{

	@Override
	public void select() {
		// TODO Auto-generated method stub
		System.out.println("Mysql에서 선택");
	}

	@Override
	public void insert() {
		// TODO Auto-generated method stub
		System.out.println("Mysql에서 삽입");

	}

	@Override
	public void update() {
		// TODO Auto-generated method stub
		System.out.println("Mysql에서 수정");

	}

	@Override
	public void delete() {
		// TODO Auto-generated method stub
		System.out.println("Mysql에서 삭제");

	}

}

package eightInterface;

public class OracleDao implements DataAccessObject{

	@Override
	public void select() {
		// TODO Auto-generated method stub
		 System.out.println("oracle DB에서 검색");
	}

	@Override
	public void insert() {
		// TODO Auto-generated method stub
		 System.out.println("oracle DB에서 삽입");
	}

	@Override
	public void update() {
		// TODO Auto-generated method stub
		 System.out.println("oracle DB에서 수정");
	}

	@Override
	public void delete() {
		// TODO Auto-generated method stub
		 System.out.println("oracle DB에서 삭제");
	}
	
}

package eightInterface;

public class DaoExample {

	public static void dbWork(DataAccessObject dao) {
		dao.select();
		dao.insert();
		dao.update();
		dao.delete();
	}
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		dbWork(new OracleDao());
		dbWork(new MySqlDao());
	}

}

5번

package eightInterface;

public interface Action {
	void work();
}

package eightInterface;

public class ActuibExample {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Action action=new Action() {
			public void work() {System.out.println("복사를합니다.");}
		};
		
		action.work();
	}

}