Java/com/study/demo4/HomeAppliance.java

package com.study.demo4;

abstract class HomeAppliance implements SmartDevice {
  protected String name;
  protected boolean isOn;

  public HomeAppliance(String name) {
    this.name = name;
    this.isOn = false;
  }

  @Override
  public void turnOn() {
    isOn = true;
  }

  @Override
  public void turnOff() {
    isOn = false;
  }

  @Override
  public String getStatus() {
    return name + " is " + (isOn ? "ON" : "OFF");
  }
}