一、先自定义一个Annotation
import java.lang.annotation.Retention;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
//先定义一个自定义注解
@Retention ( RUNTIME )
@interface MyAnnotation1{
public Class<?> target3() ;
}
二、定义一个接口及接口的实现
interface IFruite{
public void eat() ;
}
class Apple implements IFruite{
@Override
public void eat() {
System.out.println ("吃一个苹果！" );
}
}
三、定义一个工厂
@MyAnnotation1(target3 = Apple.class)
class Factory{
public static <T> T getIntance() throws IllegalAccessException, InstantiationException {
MyAnnotation1 mt =Factory.class.getAnnotation (MyAnnotation1.class) ;
return (T)mt.target3().newInstance();
}
}
四、测试类
public class Annotation与工厂设计模式 {
public static void main(String[] args) throws InstantiationException, IllegalAccessException {
IFruite fruite=Factory.getIntance ();
fruite.eat ();
}
}
