裝飾者設計模式的前提條件:
- 增強類和被增強類必須實現同一個接口
- 增強類中要有引用指向被增強類
增強類和被增強類共同實現的接口(以Car舉例):
package demo2; public interface Car { public abstract void run(); public abstract void stop(); }
需要被增強的類(奇瑞QQ):
package demo2; public class QQ implements Car { @Override public void run() { System.out.println("QQ能跑60邁!"); } @Override public void stop() { System.out.println("QQ剎車....停住"); } }
增強類CarWapper:
package demo2; public class CarWrapper implements Car { private Car car; public CarWrapper(Car car) { this.car = car; } @Override public void run() { System.out.println( "增強后,超過100邁。"); } @Override public void stop() { car.stop(); } }
測試類WapperTest:
package demo2; public class WapperTest { /** * 裝飾者模式前提條件: * 1.被增強類和增強類必須實現同一個接口 * 2.增強類要有引用指向被增強類 * @param args */
public static void main(String[] args) { Car car = new CarWrapper(new QQ()); car.run(); car.stop(); } }
被增強后: