Java Interface 接口

 

 

 

 

 

 

 

 

UsbInterface.java

package com;

public interface UsbInterface {
  abstract public void start();
  abstract public void stop();
}

　　

Camera.java

package com;

public class Camera implements UsbInterface{
  @Override
  public void start(){
    System.out.println("camera start");
  }
  @Override
  public void stop(){
    System.out.println("camera stop");
  }
}

　　

Phone.java

package com;

public class Phone implements UsbInterface{
  @Override
  public void start() {
    System.out.println("phone start");
  }

  @Override
  public void stop() {
    System.out.println("phone stop");
  }
}

　　

Computer.java

package com;

public class Computer {
  public void work(UsbInterface usbInterface){
    usbInterface.start();
    usbInterface.stop();
  }
}

　　

Test.java

package com;

import org.jetbrains.annotations.NotNull;


public class Test {
  public static void main(String @NotNull [] args) {
    Camera camera = new Camera();
    Phone phone = new Phone();
    Computer computer = new Computer();
    computer.work(camera);
    computer.work(phone);
  }
}

　　

DBInterface.java

 

package com;

public interface DBInterface {
  public void connect();

  public void close();
}

 

　　

MySQL.java

package com;

public class MySQL implements DBInterface {
  @Override
  public void connect() {
    System.out.println("connect MySQL");
  }

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

　　

Oracle.java

package com;

public class Oracle implements DBInterface {
  @Override
  public void connect() {
    System.out.println("connect oracle");
  }

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

　　

Test.java

package com;

import org.jetbrains.annotations.NotNull;


public class Test {
  public static void main(String @NotNull [] args) {
    MySQL mySQL = new MySQL();
    Oracle oracle = new Oracle();
    test(mySQL);
    test(oracle);
  }

  public static void test(DBInterface dbInterface) {
    dbInterface.connect();
    dbInterface.close();
  }
}