Spring学习（21）--- AOP之Advice应用（上）

前置通知（Before advice）	在某个连接点（join point）之前执行的通知，但不能阻止连接点前的执行（除非它抛出异常）
返回后通知（After returning advice）	在某个连接点（join point）正常完成后执行的通知
抛出异常后通知（After throwing advice）	在方法抛出异常退出时执行的通知
后通知（After(finally) advice）	当某个连接点退出的时候执行的通知（无论是正常返回还是异常退出）
环绕通知（Around advice）	包围一个连接点（join point）的通知

导入需要的包：aspectjweaver.jar、aopalliance-1.0.jar

（一）Before Advice

例子：

新建两个类：

package com.aop.schema;
/**
*
* 切面类
*
*/
public class MyAspect {

	public void before(){
		System.out.println("MyAspect.before");
	}
}

package com.aop.schema;
/**
*
* 业务类
*
*/
public class ApsectBiz {

	public void biz(){
		System.out.println("ApsectBiz.biz");
	}
}

XML配置：

<?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:aop="http://www.springframework.org/schema/aop"
        xmlns:context="http://www.springframework.org/schema/context"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-4.1.xsd
            http://www.springframework.org/schema/aop
            http://www.springframework.org/schema/aop/spring-aop-4.1.xsd">
         
     <bean id="myAspect" class="com.aop.schema.MyAspect"></bean>
      
     <bean id="apsectBiz" class="com.aop.schema.ApsectBiz"></bean>
      
     <aop:config>
          <aop:aspect id="myAspectAOP" ref="myAspect">
            <aop:pointcut id="myPointcut" expression="execution(* com.aop.schema.ApsectBiz.*(..))" />
            <aop:before method="before" pointcut-ref="myPointcut"/>
          </aop:aspect>
     </aop:config>
 
</beans>

单元测试：

package com.aop.schema;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class UnitTest {

	@Test
	public void test(){
		ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring-aop.xml");
		ApsectBiz biz = (ApsectBiz)context.getBean("apsectBiz");
		biz.biz();
	}
}

结果：

七月 09, 2015 10:30:24 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@31b3c607: startup date [Thu Jul 09 22:30:24 CST 2015]; root of context hierarchy
七月 09, 2015 10:30:24 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [spring-aop.xml]
MyAspect.before
ApsectBiz.biz

PS：ApsectBiz.biz是业务方法，在它之前，执行了前置通知MyAspect.before，符合想要的结果

（二）After returning advice

例子：

修改一下切面类MyAspect（添加afterreturning方法）：

package com.aop.schema;
/**
*
* 切面类
*
*/
public class MyAspect {

	public void before(){
		System.out.println("MyAspect.before");
	}
	
	public void afterreturning(){
		System.out.println("MyAspect.afterreturning");
	}
}

XML配置修改为：

<?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:aop="http://www.springframework.org/schema/aop"
        xmlns:context="http://www.springframework.org/schema/context"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-4.1.xsd
            http://www.springframework.org/schema/aop
            http://www.springframework.org/schema/aop/spring-aop-4.1.xsd">
         
     <bean id="myAspect" class="com.aop.schema.MyAspect"></bean>
      
     <bean id="apsectBiz" class="com.aop.schema.ApsectBiz"></bean>
      
     <aop:config>
          <aop:aspect id="myAspectAOP" ref="myAspect">
            <aop:pointcut id="myPointcut" expression="execution(* com.aop.schema.ApsectBiz.*(..))" />
            <aop:before method="before" pointcut-ref="myPointcut"/>
            <aop:after-returning method="afterreturning" pointcut-ref="myPointcut"/>
          </aop:aspect>
     </aop:config>
 
</beans>

单元测试同上：

结果：

七月 09, 2015 10:38:41 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@31b3c607: startup date [Thu Jul 09 22:38:41 CST 2015]; root of context hierarchy
七月 09, 2015 10:38:41 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [spring-aop.xml]
MyAspect.before
ApsectBiz.biz
MyAspect.afterreturning

（三）After throwing advice

说明：使用throwing属性来指定可被传递的异常的参数名称

例子：

修改一下切面类MyAspect（添加afterthrowing方法）：

package com.aop.schema;
/**
*
* 切面类
*
*/
public class MyAspect {

	public void before(){
		System.out.println("MyAspect.before");
	}
	
	public void afterreturning(){
		System.out.println("MyAspect.afterreturning");
	}
	
	public void afterthrowing(){
		System.out.println("MyAspect.afterthrowing");
	}
}

修改业务类ApsectBiz（抛出一个异常）：

package com.aop.schema;

/**
*
* 业务类
*
*/
public class ApsectBiz {

	public void biz(){
		System.out.println("ApsectBiz.biz");
		throw new RuntimeException();  //故意抛出异常
	}
}

XML配置：

<?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:aop="http://www.springframework.org/schema/aop"
        xmlns:context="http://www.springframework.org/schema/context"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-4.1.xsd
            http://www.springframework.org/schema/aop
            http://www.springframework.org/schema/aop/spring-aop-4.1.xsd">
         
     <bean id="myAspect" class="com.aop.schema.MyAspect"></bean>
      
     <bean id="apsectBiz" class="com.aop.schema.ApsectBiz"></bean>
      
     <aop:config>
          <aop:aspect id="myAspectAOP" ref="myAspect">
            <aop:pointcut id="myPointcut" expression="execution(* com.aop.schema.ApsectBiz.*(..))" />
            <aop:before method="before" pointcut-ref="myPointcut"/>
            <aop:after-returning method="afterreturning" pointcut-ref="myPointcut"/>
            <aop:after-throwing method="afterthrowing" pointcut-ref="myPointcut"/>
          </aop:aspect>
     </aop:config>
 
</beans>

单元测试同上：

测试结果：

七月 09, 2015 10:47:46 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@31b3c607: startup date [Thu Jul 09 22:47:46 CST 2015]; root of context hierarchy
七月 09, 2015 10:47:46 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [spring-aop.xml]
MyAspect.before
ApsectBiz.biz
MyAspect.afterthrowing

PS：有没有发现有什么问题？ MyAspect.afterreturning没有了，biz()中抛出异常，biz()方法没有正常返回，所以MyAspect.afterreturning没有了。

（四）After（finally） advice

修改一下切面类MyAspect（添加after方法）：

package com.aop.schema;
/**
*
* 切面类
*
*/
public class MyAspect {

	public void before(){
		System.out.println("MyAspect.before");
	}
	
	public void afterreturning(){
		System.out.println("MyAspect.afterreturning");
	}
	
	public void afterthrowing(){
		System.out.println("MyAspect.afterthrowing");
	}
	
	public void after(){
		System.out.println("MyAspect.after");
	}
}

XML配置：

<?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:aop="http://www.springframework.org/schema/aop"
        xmlns:context="http://www.springframework.org/schema/context"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-4.1.xsd
            http://www.springframework.org/schema/aop
            http://www.springframework.org/schema/aop/spring-aop-4.1.xsd">
         
     <bean id="myAspect" class="com.aop.schema.MyAspect"></bean>
      
     <bean id="apsectBiz" class="com.aop.schema.ApsectBiz"></bean>
      
     <aop:config>
          <aop:aspect id="myAspectAOP" ref="myAspect">
            <aop:pointcut id="myPointcut" expression="execution(* com.aop.schema.ApsectBiz.*(..))" />
            <aop:before method="before" pointcut-ref="myPointcut"/>
            <aop:after-returning method="afterreturning" pointcut-ref="myPointcut"/>
            <aop:after-throwing method="afterthrowing" pointcut-ref="myPointcut"/>
            <aop:after method="after" pointcut-ref="myPointcut"/>
          </aop:aspect>
     </aop:config>
 
</beans>

单元测试同上：

结果：

七月 09, 2015 10:56:10 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@31b3c607: startup date [Thu Jul 09 22:56:10 CST 2015]; root of context hierarchy
七月 09, 2015 10:56:10 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [spring-aop.xml]
MyAspect.before
ApsectBiz.biz
MyAspect.afterthrowing
MyAspect.after

（五）Around advice

注意：通知方法的第一个参数必ProceedingJoinPoint类型

例子：

修改一下切面类MyAspect（添加around方法）：

package com.aop.schema;

import org.aspectj.lang.ProceedingJoinPoint;

/**
*
* 切面类
*
*/
public class MyAspect {

	public void before(){
		System.out.println("MyAspect.before");
	}
	
	public void afterreturning(){
		System.out.println("MyAspect.afterreturning");
	}
	
	public void afterthrowing(){
		System.out.println("MyAspect.afterthrowing");
	}
	
	public void after(){
		System.out.println("MyAspect.after");
	}
	
	public void around(ProceedingJoinPoint pjp) throws Throwable{
		System.out.println("MyAspect.around_1");
		Object obj=pjp.proceed();
		System.out.println("MyAspect.around_2");
	}
}

XML配置：

<?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:aop="http://www.springframework.org/schema/aop"
        xmlns:context="http://www.springframework.org/schema/context"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-4.1.xsd
            http://www.springframework.org/schema/aop
            http://www.springframework.org/schema/aop/spring-aop-4.1.xsd">
         
     <bean id="myAspect" class="com.aop.schema.MyAspect"></bean>
      
     <bean id="apsectBiz" class="com.aop.schema.ApsectBiz"></bean>
      
     <aop:config>
          <aop:aspect id="myAspectAOP" ref="myAspect">
            <aop:pointcut id="myPointcut" expression="execution(* com.aop.schema.ApsectBiz.*(..))" />
            <aop:before method="before" pointcut-ref="myPointcut"/>
            <aop:after-returning method="afterreturning" pointcut-ref="myPointcut"/>
            <aop:after-throwing method="afterthrowing" pointcut-ref="myPointcut"/>
            <aop:after method="after" pointcut-ref="myPointcut"/>
            <aop:around method="around" pointcut-ref="myPointcut"/>
          </aop:aspect>
     </aop:config>
 
</beans>

单元测试同上：

结果：

七月 09, 2015 11:15:20 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@31b3c607: startup date [Thu Jul 09 23:15:20 CST 2015]; root of context hierarchy
七月 09, 2015 11:15:20 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [spring-aop.xml]
MyAspect.before
MyAspect.around_1
ApsectBiz.biz
java.lang.RuntimeException
    at com.aop.schema.ApsectBiz.biz(ApsectBiz.java:11)
    at com.aop.schema.ApsectBiz$$FastClassBySpringCGLIB$$ae10254d.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:717)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:85)
    at com.aop.schema.MyAspect.around(MyAspect.java:31)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:621)
    at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:610)
    at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:68)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.aspectj.AspectJAfterAdvice.invoke(AspectJAfterAdvice.java:43)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:58)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.adapter.AfterReturningAdviceInterceptor.invoke(AfterReturningAdviceInterceptor.java:52)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:52)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)
    at com.aop.schema.ApsectBiz$$EnhancerBySpringCGLIB$$1fbf7bae.biz(<generated>)
    at com.aop.schema.UnitTest.test(UnitTest.java:13)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
MyAspect.after
MyAspect.afterreturning

PS：有异常，仔细看，原来是around(ProceedingJoinPoint pjp)的try catch捕捉到了biz（）抛出的异常，现在把异常注释掉（try catch里面怎么处理异常？这里要看具体的业务需要，这里先注释掉）

package com.aop.schema;
/**
*
* 业务类
*
*/
public class ApsectBiz {

	public void biz(){
		System.out.println("ApsectBiz.biz");
		//throw new RuntimeException();  //故意抛出异常
	}
}

测试结果：

七月 09, 2015 11:18:17 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@31b3c607: startup date [Thu Jul 09 23:18:17 CST 2015]; root of context hierarchy
七月 09, 2015 11:18:17 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [spring-aop.xml]
MyAspect.before
MyAspect.around_1
ApsectBiz.biz
MyAspect.around_2
MyAspect.after
MyAspect.afterreturning