在工廠對象上調(diào)用創(chuàng)建方法，生成接口的某個實(shí)現(xiàn)的對象

通過這種方式，接口與實(shí)現(xiàn)分離

• 方法接口

/**
 * 方法接口
 */
public interface Service {
    void method1();
    void method2();
}

• 工廠方法接口

/**
 * 工廠方法接口
 */
public interface ServiceFactory {
    Service getService();
}

• 方法實(shí)現(xiàn)

/**
 * 實(shí)現(xiàn)類1
 */
public class Impl1 implements Service {
    public void method1(){System.out.println("Impl1 method1");}
    public void method2(){System.out.println("Impl1 method2");}
}

/**
 * 實(shí)現(xiàn)類2
 */
public class Impl2 implements Service{
    public void method1(){System.out.println("Impl2 method1");}
    public void method2(){System.out.println("Impl2 method2");}
}

• 工廠方法實(shí)現(xiàn)

public class ImplFactory1 implements ServiceFactory {
    public Service getService(){
        return new Impl1();
    }
}

public class ImplFactory2 implements  ServiceFactory{
    public Service getService(){
        return new Impl2();
    }
}

• 測試

public class Test {
    public static void main(String[] args){
        ServiceFactory sf1 = new ImplFactory1();
        Service s1 = sf1.getService();
        s1.method1();
        s1.method2();

        ServiceFactory sf2 = new ImplFactory2();
        Service s2 = sf2.getService();
        s2.method1();
        s2.method2();
    }
}