Spring对AOP的实现提供了很好的支持。下面我们就使用Spring的注解来完成AOP做一个例子。
首先,为了使用Spring的AOP注解功能,必须导入如下几个包。aspectjrt.jar,aspectjweaver.jar,cglib-nodep.jar.
然后我们写一个接口
package com.bird.service; public interface PersonServer { public void save(String name); public void update(String name, Integer id); public String getPersonName(Integer id); }
和一个接口实现类
package com.bird.service.impl; import com.bird.service.PersonServer; public class PersonServiceBean implements PersonServer{ @Override public void save(String name) { System.out.println("我是save方法"); // throw new RuntimeException(); } @Override public void update(String name, Integer id) { System.out.println("我是update()方法"); } @Override public String getPersonName(Integer id) { System.out.println("我是getPersonName()方法"); return "xxx"; } }
下面使用Spring注解方式对这个Bean进行方法拦截
package com.bird.service; import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.annotation.After; import org.aspectj.lang.annotation.AfterReturning; import org.aspectj.lang.annotation.AfterThrowing; import org.aspectj.lang.annotation.Around; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Before; import org.aspectj.lang.annotation.Pointcut; /** * 切面 * @author Bird * */ @Aspect public class MyInterceptor { @Pointcut("execution(* com.bird.service.impl.PersonServiceBean.*(..))") private void anyMethod(){}//定义一个切入点 @Before("anyMethod() && args(name)") public void doAccessCheck(String name){ System.out.println(name); System.out.println("前置通知"); } @AfterReturning("anyMethod()") public void doAfter(){ System.out.println("后置通知"); } @After("anyMethod()") public void after(){ System.out.println("最终通知"); } @AfterThrowing("anyMethod()") public void doAfterThrow(){ System.out.println("例外通知"); } @Around("anyMethod()") public Object doBasicProfiling(ProceedingJoinPoint pjp) throws Throwable{ System.out.println("进入环绕通知"); Object object = pjp.proceed();//执行该方法 System.out.println("退出方法"); return object; } } @Pointcut("execution(* com.bird.service.impl.PersonServiceBean.*(..))")这句话是方法切入点,execution为执行的意思,*代表任意返回值,然后是包名,.*意思是包下面的所有子包。(..)代
表各种方法.
然后下面的注解就比较简单了,就是在使用方法前和中,还有环绕拦截/
然后在Spring的配置文件中继续配置Bean,需要打开AOP命名空间
然后建立一个Junit测试
package junit.test; import org.junit.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.bird.service.PersonServer; public class SpringAOPTest { @Test public void inteceptorTest(){ ApplicationContext ctx = new ClassPathXmlApplicationContext("beanAop.xml"); PersonServer bean = (PersonServer)ctx.getBean("personServiceBean"); bean.save(null); } }
测试结果为
2012-3-12 18:08:39 org.springframework.context.support.AbstractApplicationContext prepareRefresh 信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@dd20f6: display name [org.springframework.context.support.ClassPathXmlApplicationContext@dd20f6]; startup date [Mon Mar 12 18:08:39 CST 2012]; root of context hierarchy 2012-3-12 18:08:40 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions 信息: Loading XML bean definitions from class path resource [beanAop.xml] 2012-3-12 18:08:40 org.springframework.context.support.AbstractApplicationContext obtainFreshBeanFactory 信息: Bean factory for application context [org.springframework.context.support.ClassPathXmlApplicationContext@dd20f6]: org.springframework.beans.factory.support.DefaultListableBeanFactory@b0bad7 2012-3-12 18:08:40 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons 信息: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@b0bad7: defining beans [org.springframework.aop.config.internalAutoProxyCreator,personServiceBean,myInterceptor]; root of factory hierarchy null 前置通知 进入环绕通知 我是save方法 后置通知 退出方法 最终通知