设计模式---简单工厂模式（学习笔记）

简单工厂事实上不是一个设计模式，比較像一种编程习惯！

首先看一下代码，从代码中理解这个编程习惯。

举个做披萨的样例：

Pizza类代码：

public interface Pizza {
    void prepare();
    void box();
    void bake();
    void cut();

}

public class CheesePizza implements Pizza {
    private String tag="CheesePizza：";
    @Override
    public void prepare() {
        System.out.println(tag+"pripare()");
    }

    @Override
    public void box() {
        System.out.println(tag+"box()");

    }

    @Override
    public void bake() {
        System.out.println(tag+"bake()");

    }

    @Override
    public void cut() {
        System.out.println(tag+"cut()");

    }



}

public class ClamPizza implements Pizza {
    private String tag="ClamPizza：";
    @Override
    public void prepare() {
        System.out.println(tag+"pripare()");
    }

    @Override
    public void box() {
        System.out.println(tag+"box()");

    }

    @Override
    public void bake() {
        System.out.println(tag+"bake()");

    }

    @Override
    public void cut() {
        System.out.println(tag+"cut()");

    }

}

public class SimplePizzaFactory {

    public Pizza createPizza(String tpye){
        Pizza pizza = null;
        if (tpye.equals("cheese")){
        pizza=new CheesePizza();
        }else if (tpye.equals("clam")){
         pizza=new ClamPizza();
        }
        return pizza;
    }
}

public  class PizzaStore {

    SimplePizzaFactory simplePizzaFactory;

    protected PizzaStore(SimplePizzaFactory simplePizzaFactory) {
        this.simplePizzaFactory = simplePizzaFactory;
    }

    protected final Pizza orderPizza(String type){
//        Pizza pizza=pizzafactory.createP(type);
        Pizza pizza=simplePizzaFactory.createPizza(type);
        pizza.prepare();
        pizza.bake();
        pizza.cut();
        pizza.box();


        return pizza;

    }


}

  public static void main(String[] args){

    PizzaStore chijiaPizzaStore=new PizzaStore(new SimplePizzaFactory());
     chijiaPizzaStore.orderPizza("cheese");
     chijiaPizzaStore.orderPizza("clam");
    }

CheesePizza：pripare()
CheesePizza：bake()
CheesePizza：cut()
CheesePizza：box()
ClamPizza：pripare()
ClamPizza：bake()
ClamPizza：cut()
ClamPizza：box()

来看一个比較通用的工厂模式框架代码：

抽象产品类：

public abstract class Product {

    public void method1(){

    };
    public abstract  void method2();
}

public class ConcreteProduct1 implements Product{

        @Override
        public void method2() {
            
        }
    }public class ConcreteProduct2 implements Product{

        @Override
        public void method2() {
            
        }
    }

public abstract  class Creator {
    /**
     *
     * @param c
     * @param <T> 參数类型能够自行设置，通常为String，emum，Class等，也能够为空
     * @return
     */
    public abstract <T extends Product> T createProducts(Class<T> c);
}

 public class ConcreteFactory extends Creator {
       

        @Override
        public <T extends Product> T createProducts(Class<T> c) {
            Product product=null;
            try {
                product= (Product) Class.forName(c.getName()).newInstance();
            } catch (InstantiationException e) {
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            }
            return (T) product;
        }
    }

 Creator creator=new ConcreteFactory();
  Product product=  creator.createProducts(COncreteProduct2.class);

假设一个模块仅须要一个工厂类，没有必要把它生产出来，使用静态方法就能够啦，把上述的抽象工厂类直接替换为详细工厂类，并使用静态方法就能够，这样就变为简单工厂模式，或者是静态工厂模式。

写的不好，希望多提意见，共同进步学习！谢谢