@Autowired自动装配的简单实现

测试类&＃xff0c;模拟Controller调用

/*** 模拟&＃64;Controller* */
public class MyController {&＃64;MyAutowiredprivate MyService myService;public void print(){String name &＃61; myService.getName();System.out.println(name);}
}

自动装配测试&＃xff1a;

public class AutowiredTest {public static void main(String[] args) {MyController myController &＃61; new MyController();//简单的自动装配reflect(myController);myController.print();}//传入需要专配的对象public static void reflect(Object obj) {Class clazz &＃61; obj.getClass();Field[] fields &＃61; clazz.getDeclaredFields();for (Field field : fields) {//获取属性 是否有注解MyAutowired annotation &＃61; field.getAnnotation(MyAutowired.class);if (annotation !&＃61; null) {field.setAccessible(true);//获取当前属性的类型&＃xff0c;有了类型后可以创建具体对象Class type &＃61; field.getType();//创建具体对象Object o &＃61; null;try {o &＃61; type.newInstance();field.set(obj, o);} catch (InstantiationException e) {e.printStackTrace();} catch (IllegalAccessException e) {e.printStackTrace();}}}}
}


自定义注解&＃xff1a;

//作用范围
&＃64;Retention(RetentionPolicy.RUNTIME)
//作用目标
&＃64;Target(ElementType.FIELD)
//继承
&＃64;Inherited
//文档记录
&＃64;Documented
public &＃64;interface MyAutowired {
}

模拟Service层&＃xff1a;

public class MyService {public String getName() {return "PersonService.getName()";}
}