单例
package com.enorth.user; /** * 李晨 * 创建时间：Jun 29, 2009 9:10:02 AM */ public class Singleton { private static Singleton singleton = null; private Singleton() { } public static Singleton getInstance() { if (singleton == null) { //防止线程安全 synchronized (Singleton. class) { if (singleton == null) { singleton = new Singleton(); return singleton; } } } return singleton; } }
简单工厂
// 产品接口 public interface Product { public void getName(); } // 具体产品A public class ProductA implements Product { public void getName() { System.out.println( " I am ProductA "); } } // 具体产品B public class ProductB implements Product { public void getName() { System.out.println( " I am ProductB "); } } // 工厂类 public class ProductCreator { public Product createProduct(String type) { if ( " A ".equals(type)) { return new ProductA(); } if ( " B ".equals(type)) { return new ProductB(); } else return null; } public static void main(String[] args) { ProductCreator creator = new ProductCreator(); creator.createProduct( " A ").getName(); creator.createProduct( " B ").getName(); } }
抽象工厂
// 产品 Plant接口 public interface Plant { } // 具体产品PlantA，PlantB public class PlantA implements Plant { public PlantA() { System.out.println( " create PlantA ! "); } public void doSomething() { System.out.println( " PlantA do something "); } } public class PlantB implements Plant { public PlantB() { System.out.println( " create PlantB ! "); } public void doSomething() { System.out.println( " PlantB do something "); } } // 产品 Fruit接口 public interface Fruit { } // 具体产品FruitA，FruitB public class FruitA implements Fruit { public FruitA() { System.out.println( " create FruitA ! "); } public void doSomething() { System.out.println( " FruitA do something "); } } public class FruitB implements Fruit { public FruitB() { System.out.println( " create FruitB ! "); } public void doSomething() { System.out.println( " FruitB do something "); } } // 抽象工厂方法 public interface AbstractFactory { public Plant createPlant(); public Fruit createFruit(); } // 具体工厂方法 public class FactoryA implements AbstractFactory { public Plant createPlant() { return new PlantA(); } public Fruit createFruit() { return new FruitA(); } } public class FactoryB implements AbstractFactory { public Plant createPlant() { return new PlantB(); } public Fruit createFruit() { return new FruitB(); } }
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