java设计模式之抽像工厂详解

public class AbstractProductA {      public AbstractProductA()   {    }}public class ProductA1 extends AbstractProductA {      public ProductA1()   {    }}public class ProductA2 extends AbstractProductA {      public ProductA2()   {    }}public class AbstractProductB {      public AbstractProductB()   {    }}public class ProductB1 extends AbstractProductB {      public ProductB1()   {    }}public class ProductB2 extends AbstractProductB {      public ProductB2()   {    }}public abstract class AbstractFactory {      public AbstractFactory()   {    }      public Abstract AbstractProductA createProductA() ;        public Abstract AbstractProductB createProductB() ;}public class ConcreteFactory1 extends AbstractFactory {      public ConcreteFactory1()   {    }      public AbstractProductA createProductA()   {    return new ProductA1();  }      public AbstractProductB createProductB()   {    return new ProductB1();  }}public class ConcreteFactory2 extends AbstractFactory {      public ConcreteFactory2()   {    }      public AbstractProductA createProductA()   {    return new ProductA2();  }      public AbstractProductB createProductB()   {    return new ProductB2();  }}