Java设计模式之静态工厂模式详解

package org.test.design.sf;
public interface IProduct {
  void work();
}

package org.test.design.sf;
public class ProductA implements IProduct {
  public void work() {
    System.out.println("Here is ProductA, for your dedicated service.");
  }
}

package org.test.design.sf;
public class ProductB implements IProduct {
  public void work() {
    System.out.println("Here is ProductB, for your dedicated service.");
  }
}

package org.test.design.sf;
/**
 * 静态工厂模式
 * @author lushuaiyin
 *
 */
public class ProductFactory {
  public static IProduct product=null;//静态
  //静态方法
  public static IProduct getProduct(String productType) throws InstantiationException, IllegalAccessException, ClassNotFoundException{
//   if(productType==null||productType.trim().equals("")){//默认创建ProductA
//     product=new ProductA();
//   }else if(productType.trim().equals("ProductA")){
//     product=new ProductA();
//   }else if(productType.trim().equals("ProductB")){
//     product=new ProductB();
//   }
    //静态工厂一般使用类的反射来构建对象，像上面的构建也可以。
    if(productType.trim().equals("ProductA")){
      product=(IProduct)Class.forName("org.test.design.sf.ProductA").newInstance();
    }else if(productType.trim().equals("ProductB")){
      product=(IProduct)Class.forName("org.test.design.sf.ProductB").newInstance();
    }
    return product;
  }
}

package org.test.design.sf;
public class TestMain {
  /**
   * @param args
   * @throws ClassNotFoundException
   * @throws IllegalAccessException
   * @throws InstantiationException
   */
  public static void main(String[] args) throws InstantiationException, IllegalAccessException, ClassNotFoundException {
    IProduct product_a=ProductFactory.getProduct("ProductA");
    product_a.work();
    IProduct product_b=ProductFactory.getProduct("ProductB");
    product_b.work();
  }
}
/*打印
Here is ProductA, for your dedicated service.
Here is ProductB, for your dedicated service.
*/