day05 Spring中自定义注解的用处-之获取自定义的Servie

 PS: 在RPC远程调用中，想要获取自定义的service的方法，就得自定义标签遍历拿到方法

PS:在spring中，两个最核心的 概念是aop和ioc，aop其实就是动态代理。 ioc 就是解决对象的创建问题。

 

 

1.自定义标签

package cn.itcast_04_springannotation.userdefinedannotation.annotation;import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; import org.springframework.stereotype.Component;@Target({ ElementType.TYPE })//注解用在接口上 @Retention(RetentionPolicy.RUNTIME)//VM将在运行期也保留注释，因此可以通过反射机制读取注解的信息 @Component public @interface RpcService {String value(); }

2.实现接口中的方法

package cn.itcast_04_springannotation.userdefinedannotation.service.impl;import cn.itcast_04_springannotation.userdefinedannotation.annotation.RpcService; import cn.itcast_04_springannotation.userdefinedannotation.service.HelloService;@RpcService("HelloServicebb") public class HelloServiceImpl implements HelloService {public String hello(String name) {return "Hello! " + name;}public void test(){System.out.println("test");} }

3.主程序测试

package cn.itcast_04_springannotation.userdefinedannotation.test;import java.lang.reflect.Method; import java.util.Map;import org.springframework.beans.BeansException; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.ApplicationContext; import org.springframework.context.ApplicationContextAware; import org.springframework.context.support.ClassPathXmlApplicationContext; import org.springframework.stereotype.Component;import cn.itcast_04_springannotation.userdefinedannotation.annotation.RpcService; import cn.itcast_04_springannotation.userdefinedannotation.service.HelloService;@Component //ApplicationContextAware会为Component组件调用setApplicationContext方法； 测试Myserver3时注释 public class MyServer implements ApplicationContextAware {@SuppressWarnings("resource")public static void main(String[] args) {ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("spring2.xml");}public void setApplicationContext(ApplicationContext ctx)throws BeansException {Map<String, Object> serviceBeanMap = ctx.getBeansWithAnnotation(RpcService.class);for (Object serviceBean : serviceBeanMap.values()) {try {//获取自定义注解上的valueString value = serviceBean.getClass().getAnnotation(RpcService.class).value();System.out.println("注解上的value: " + value);//反射被注解类，并调用指定方法Method method = serviceBean.getClass().getMethod("hello",new Class[] { String.class });Object invoke = method.invoke(serviceBean, "bbb");System.out.println(invoke);} catch (Exception e) {e.printStackTrace();}}}}

log4j:WARN No appenders could be found for logger (org.springframework.core.env.StandardEnvironment).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
注解上的value: HelloServicebb
Hello! bbb

 

 

---------------------------------下面讲解一下关于spring和junit4的测试方式

package cn.itcast_04_springannotation.userdefinedannotation.test;import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import cn.itcast_04_springannotation.userdefinedannotation.service.HelloService;@RunWith(SpringJUnit4ClassRunner.class)//加载类 @ContextConfiguration(locations = "classpath:spring2.xml")//加载文件 @Component public class MyServer3 {@AutowiredHelloService helloService;@Testpublic void helloTest1() {System.out.println("开始junit测试……");String hello = helloService.hello("ooooooo");System.out.println(hello);}}

 

转载于:https://www.cnblogs.com/bee-home/p/7851770.html

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