Spring AOP 中 advice 的四种类型 before after throwing advice around

spring  AOP(Aspect-oriented programming) 是用于切面编程，简单的来说：AOP相当于一个拦截器，去拦截一些处理，例如：当一个方法执行的时候，Spring 能够拦截正在执行的方法，在方法执行的前或者后增加额外的功能和处理。

在Spring AOP中支持4中类型的通知：

1：before advice 在方法执行前执行。

2：after  returning  advice 在方法执行后返回一个结果后执行。

3：after  throwing advice 在方法执行过程中抛出异常的时候执行。

4：Around  advice 在方法执行前后和抛出异常时执行，相当于综合了以上三种通知。

下面是一个简单的AOP  advice 的例子：

首先给出一个简单的Spring 注入的例子，

定义一个Book类：

1. package com.myapp.core.aop.advice;
2. public class Book {
3. private  String  name;
4. private  String  url;
5. private   int    pages;
6. public String getName() {
7. return name;
8. }
9. public void setName(String name) {
10. this.name = name;
11. }
12. public String getUrl() {
13. return url;
14. }
15. public void setUrl(String url) {
16. this.url = url;
17. }
18. public int getPages() {
19. return pages;
20. }
21. public void setPages(int pages) {
22. this.pages = pages;
23. }
24. public  void  printName(){
25. System.out.println("Book name "+ this.name);
26. }
27. public  void  printUrl(){
28. System.out.println("Book URL "+this.url);
29. }
30. public  void  printThrowException(){
31. throw  new  IllegalArgumentException();
32. }
33. }

package com.myapp.core.aop.advice;

public class Book {
   private  String  name;
   private  String  url;
   private   int    pages;

	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getUrl() {
		return url;
	}
	public void setUrl(String url) {
		this.url = url;
	}
	public int getPages() {
		return pages;
	}
	public void setPages(int pages) {
		this.pages = pages;
	}

	public  void  printName(){
		System.out.println("Book name "+ this.name);
	}

	public  void  printUrl(){
		System.out.println("Book URL "+this.url);
	}

	public  void  printThrowException(){
		throw  new  IllegalArgumentException();
	}

}

相应的配置文件：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <beans xmlns="http://www.springframework.org/schema/beans"
3. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4. xsi:schemaLocation="http://www.springframework.org/schema/beans
5. http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
6. <!-- more bean definitions for data access objects go here -->
7. <bean id="book" class="com.myapp.core.aop.advice.Book">
8. <property name="name" value="Effective java" />
9. <property name="url" value="www.google.cn"/>
10. <property name="pages" value="300" />
11. </bean>
12. </beans>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

  <!-- more bean definitions for data access objects go here -->

    <bean id="book" class="com.myapp.core.aop.advice.Book">
	    <property name="name" value="Effective java" />
	    <property name="url" value="www.google.cn"/>
	    <property name="pages" value="300" />
    </bean>
</beans>

对应的测试类：

1. package com.myapp.core.aop.advice;
2. import org.springframework.context.ApplicationContext;
3. import org.springframework.context.support.ClassPathXmlApplicationContext;
4. public class MainTest {
5. public static void main(String[] args) {
6. ApplicationContext  context  = new  ClassPathXmlApplicationContext("resource/aop.xml");
7. Book   book  =   (Book) context.getBean("book");
8. System.out.println("---------------------");
9. book.printName();
10. System.out.println("---------------------");
11. book.printUrl();
12. System.out.println("----------------------");
13. try{
14. book.printThrowException();
15. }catch(Exception e){
16. //  e.printStackTrace();
17. }
18. }
19. }

package com.myapp.core.aop.advice;

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

public class MainTest {
   public static void main(String[] args) {

	   ApplicationContext  context  = new  ClassPathXmlApplicationContext("resource/aop.xml");

	   Book   book  =   (Book) context.getBean("book");

	   System.out.println("---------------------");

	   book.printName();

	   System.out.println("---------------------");

	   book.printUrl();

	   System.out.println("----------------------");

	   try{

		  book.printThrowException();

	   }catch(Exception e){
		 //  e.printStackTrace();
	   }

}
}

输出结果：

1. 三月 20, 2013 11:01:01 上午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
2. INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@11e831: startup date [Wed Mar 20 11:01:01 CST 2013]; root of context hierarchy
3. 三月 20, 2013 11:01:01 上午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
4. INFO: Loading XML bean definitions from class path resource [resource/aop.xml]
5. 三月 20, 2013 11:01:01 上午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
6. INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@13b5500: defining beans [book]; root of factory hierarchy
7. ---------------------
8. Book name Effective java
9. ---------------------
10. Book URL www.google.cn
11. ----------------------

三月 20, 2013 11:01:01 上午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@11e831: startup date [Wed Mar 20 11:01:01 CST 2013]; root of context hierarchy
三月 20, 2013 11:01:01 上午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [resource/aop.xml]
三月 20, 2013 11:01:01 上午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@13b5500: defining beans [book]; root of factory hierarchy
---------------------
Book name Effective java
---------------------
Book URL www.google.cn
----------------------

下面对以上的Book加上Spring   AOP   advices

1：before  advice

before advice将在方法执行前执行，创建一个实现MethodBeforeAdvice接口的类能够定义执行方法前的操作。

类如下：

1. package com.myapp.core.aop.advice;
2. import java.lang.reflect.Method;
3. import org.springframework.aop.MethodBeforeAdvice;
4. public class BeforeMethod  implements MethodBeforeAdvice {
5. @Override
6. public void before(Method arg0, Object[] arg1, Object arg2)
7. throws Throwable {
8. // TODO Auto-generated method stub
9. System.out.println("Before  Method");
10. System.out.println("--------------------");
11. }
12. }

package com.myapp.core.aop.advice;

import java.lang.reflect.Method;

import org.springframework.aop.MethodBeforeAdvice;

public class BeforeMethod  implements MethodBeforeAdvice {

	@Override
	public void before(Method arg0, Object[] arg1, Object arg2)
			throws Throwable {
		// TODO Auto-generated method stub

		System.out.println("Before  Method");
		System.out.println("--------------------");

	}

}

配置对应的bean：

在aop.xml中配置，创建一个BeforeMethod类，一个新的代理命名为：bookProxy

1： target 设置你想拦截的bean

2：interceptorNames设置通知，你想作用于proxy/target上的

对应的配置文件如下：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <beans xmlns="http://www.springframework.org/schema/beans"
3. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4. xsi:schemaLocation="http://www.springframework.org/schema/beans
5. http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
6. <!-- more bean definitions for data access objects go here -->
7. <bean id="book" class="com.myapp.core.aop.advice.Book">
8. <property name="name" value="Effective java" />
9. <property name="url" value="www.google.cn"/>
10. <property name="pages" value="300" />
11. </bean>
12. <bean id="beforeMethodBean" class="com.myapp.core.aop.advice.BeforeMethod" />
13. <bean id="bookProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
14. <property name="target" ref="book"/>
15. <property name="interceptorNames">
16. <list>
17. <value>beforeMethodBean</value>
18. </list>
19. </property>
20. </bean>
21. </beans>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

  <!-- more bean definitions for data access objects go here -->

    <bean id="book" class="com.myapp.core.aop.advice.Book">
	    <property name="name" value="Effective java" />
	    <property name="url" value="www.google.cn"/>
	    <property name="pages" value="300" />
    </bean>

    <bean id="beforeMethodBean" class="com.myapp.core.aop.advice.BeforeMethod" />

    <bean id="bookProxy" class="org.springframework.aop.framework.ProxyFactoryBean">

     <property name="target" ref="book"/>

     <property name="interceptorNames">
       <list>
        <value>beforeMethodBean</value>
       </list>
     </property>

     </bean>
</beans>

注意：为了使用proxy（代理）我们需要引入 CGLIB2， pom.xml文件中注入如下：

1. <dependency>
2. <groupId>cglib</groupId>
3. <artifactId>cglib</artifactId>
4. <version>2.2.2</version>
5. </dependency>

	<dependency>
		<groupId>cglib</groupId>
		<artifactId>cglib</artifactId>
		<version>2.2.2</version>
	</dependency>

运行测试类：

1. package com.myapp.core.aop.advice;
2. import org.springframework.context.ApplicationContext;
3. import org.springframework.context.support.ClassPathXmlApplicationContext;
4. public class MainTest {
5. public static void main(String[] args) {
6. ApplicationContext  context  = new  ClassPathXmlApplicationContext("resource/aop.xml");
7. Book   book  =   (Book) context.getBean("bookProxy");
8. System.out.println("---------------------");
9. book.printName();
10. System.out.println("---------------------");
11. book.printUrl();
12. System.out.println("----------------------");
13. try{
14. book.printThrowException();
15. }catch(Exception e){
16. //  e.printStackTrace();
17. }
18. }
19. }

package com.myapp.core.aop.advice;

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

public class MainTest {
   public static void main(String[] args) {

	   ApplicationContext  context  = new  ClassPathXmlApplicationContext("resource/aop.xml");

	   Book   book  =   (Book) context.getBean("bookProxy");

	   System.out.println("---------------------");

	   book.printName();

	   System.out.println("---------------------");

	   book.printUrl();

	   System.out.println("----------------------");

	   try{

		  book.printThrowException();

	   }catch(Exception e){
		 //  e.printStackTrace();
	   }

}
}

注意以上获得的是代理bean；

运行结果如下：

1. 三月 20, 2013 2:18:56 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
2. INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@eb67e8: startup date [Wed Mar 20 14:18:55 CST 2013]; root of context hierarchy
3. 三月 20, 2013 2:18:56 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
4. INFO: Loading XML bean definitions from class path resource [resource/aop.xml]
5. 三月 20, 2013 2:18:57 下午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
6. INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@157985: defining beans [book,beforeMethodBean,bookProxy]; root of factory hierarchy
7. ---------------------
8. Before  Method
9. --------------------
10. Book name Effective java
11. ---------------------
12. Before  Method
13. --------------------
14. Book URL www.google.cn
15. ----------------------
16. Before  Method
17. --------------------

三月 20, 2013 2:18:56 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@eb67e8: startup date [Wed Mar 20 14:18:55 CST 2013]; root of context hierarchy
三月 20, 2013 2:18:56 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [resource/aop.xml]
三月 20, 2013 2:18:57 下午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@157985: defining beans [book,beforeMethodBean,bookProxy]; root of factory hierarchy
---------------------
Before  Method
--------------------
Book name Effective java
---------------------
Before  Method
--------------------
Book URL www.google.cn
----------------------
Before  Method
--------------------

2： after  advice

在方法运行返回结果后将执行这个 afterReturning方法，创建的这个类必须实现：AfterReturningAdvice接口

1. package com.myapp.core.aop.advice;
2. import java.lang.reflect.Method;
3. import org.springframework.aop.AfterReturningAdvice;
4. public class AfterMethod  implements  AfterReturningAdvice {
5. @Override
6. public void afterReturning(Object arg0, Method arg1, Object[] arg2,
7. Object arg3) throws Throwable {
8. // TODO Auto-generated method stub
9. System.out.println("-------------------");
10. System.out.println("After  method ");
11. }
12. }

package com.myapp.core.aop.advice;

import java.lang.reflect.Method;

import org.springframework.aop.AfterReturningAdvice;

public class AfterMethod  implements  AfterReturningAdvice {

	@Override
	public void afterReturning(Object arg0, Method arg1, Object[] arg2,
			Object arg3) throws Throwable {
		// TODO Auto-generated method stub

		System.out.println("-------------------");

		System.out.println("After  method ");

	}

}

xml配置文件：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <beans xmlns="http://www.springframework.org/schema/beans"
3. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4. xsi:schemaLocation="http://www.springframework.org/schema/beans
5. http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
6. <!-- more bean definitions for data access objects go here -->
7. <bean id="book" class="com.myapp.core.aop.advice.Book">
8. <property name="name" value="Effective java" />
9. <property name="url" value="www.google.cn"/>
10. <property name="pages" value="300" />
11. </bean>
12. <bean id="beforeMethodBean" class="com.myapp.core.aop.advice.BeforeMethod" />
13. <bean id="afterMethodBean" class="com.myapp.core.aop.advice.AfterMethod" />
14. <bean id="bookProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
15. <property name="target" ref="book"/>
16. <property name="interceptorNames">
17. <list>
18. <value>beforeMethodBean</value>
19. <value>afterMethodBean</value>
20. </list>
21. </property>
22. </bean>
23. </beans>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

  <!-- more bean definitions for data access objects go here -->

    <bean id="book" class="com.myapp.core.aop.advice.Book">
	    <property name="name" value="Effective java" />
	    <property name="url" value="www.google.cn"/>
	    <property name="pages" value="300" />
    </bean>

    <bean id="beforeMethodBean" class="com.myapp.core.aop.advice.BeforeMethod" />

      <bean id="afterMethodBean" class="com.myapp.core.aop.advice.AfterMethod" />

    <bean id="bookProxy" class="org.springframework.aop.framework.ProxyFactoryBean">

     <property name="target" ref="book"/>

     <property name="interceptorNames">
       <list>
        <value>beforeMethodBean</value>
        <value>afterMethodBean</value>
       </list>
     </property>

     </bean>
</beans>

运行结果如下：

1. 三月 20, 2013 2:22:19 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
2. INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@eb67e8: startup date [Wed Mar 20 14:22:19 CST 2013]; root of context hierarchy
3. 三月 20, 2013 2:22:19 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
4. INFO: Loading XML bean definitions from class path resource [resource/aop.xml]
5. 三月 20, 2013 2:22:20 下午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
6. INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@157985: defining beans [book,beforeMethodBean,afterMethodBean,bookProxy]; root of factory hierarchy
7. ---------------------
8. Before  Method
9. --------------------
10. Book name Effective java
11. -------------------
12. After  method
13. ---------------------
14. Before  Method
15. --------------------
16. Book URL www.google.cn
17. -------------------
18. After  method
19. ----------------------
20. Before  Method
21. --------------------

三月 20, 2013 2:22:19 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@eb67e8: startup date [Wed Mar 20 14:22:19 CST 2013]; root of context hierarchy
三月 20, 2013 2:22:19 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [resource/aop.xml]
三月 20, 2013 2:22:20 下午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@157985: defining beans [book,beforeMethodBean,afterMethodBean,bookProxy]; root of factory hierarchy
---------------------
Before  Method
--------------------
Book name Effective java
-------------------
After  method
---------------------
Before  Method
--------------------
Book URL www.google.cn
-------------------
After  method
----------------------
Before  Method
--------------------

3：after  throwing  advice

当方法执行抛出一个异常后，会执行这个方法，创建一个类实现：ThrowsAdvice接口，创建一个afterThrowing拦截：IllegalArgumentException异常。

类如下：

1. package com.myapp.core.aop.advice;
2. import org.springframework.aop.ThrowsAdvice;
3. public class ThrowException  implements ThrowsAdvice{
4. public  void  afterThrowing(IllegalArgumentException e)  throws  Throwable{
5. System.out.println("after Throwing  Exception");
6. }
7. }

package com.myapp.core.aop.advice;

import org.springframework.aop.ThrowsAdvice;

public class ThrowException  implements ThrowsAdvice{

	public  void  afterThrowing(IllegalArgumentException e)  throws  Throwable{
		System.out.println("after Throwing  Exception");
	}
}

xml中配置文件如下：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <beans xmlns="http://www.springframework.org/schema/beans"
3. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4. xsi:schemaLocation="http://www.springframework.org/schema/beans
5. http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
6. <!-- more bean definitions for data access objects go here -->
7. <bean id="book" class="com.myapp.core.aop.advice.Book">
8. <property name="name" value="Effective java" />
9. <property name="url" value="www.google.cn"/>
10. <property name="pages" value="300" />
11. </bean>
12. <!-- before  advice -->
13. <bean id="beforeMethodBean" class="com.myapp.core.aop.advice.BeforeMethod" />
14. <!-- after  advice -->
15. <bean id="afterMethodBean" class="com.myapp.core.aop.advice.AfterMethod" />
16. <!-- throwing  advice -->
17. <bean id="throwException" class="com.myapp.core.aop.advice.ThrowException" />
18. <bean id="bookProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
19. <property name="target" ref="book"/>
20. <property name="interceptorNames">
21. <list>
22. <value>beforeMethodBean</value>
23. <value>afterMethodBean</value>
24. <value>throwException</value>
25. </list>
26. </property>
27. </bean>
28. </beans>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

  <!-- more bean definitions for data access objects go here -->

    <bean id="book" class="com.myapp.core.aop.advice.Book">
	    <property name="name" value="Effective java" />
	    <property name="url" value="www.google.cn"/>
	    <property name="pages" value="300" />
    </bean>

    <!-- before  advice -->
    <bean id="beforeMethodBean" class="com.myapp.core.aop.advice.BeforeMethod" />

    <!-- after  advice -->
      <bean id="afterMethodBean" class="com.myapp.core.aop.advice.AfterMethod" />

      <!-- throwing  advice -->

      <bean id="throwException" class="com.myapp.core.aop.advice.ThrowException" />

    <bean id="bookProxy" class="org.springframework.aop.framework.ProxyFactoryBean">

     <property name="target" ref="book"/>

     <property name="interceptorNames">
       <list>
        <value>beforeMethodBean</value>
        <value>afterMethodBean</value>
        <value>throwException</value>
       </list>
     </property>

     </bean>
</beans>

执行结果如下：

1. 三月 20, 2013 2:37:36 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
2. INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@eb67e8: startup date [Wed Mar 20 14:37:36 CST 2013]; root of context hierarchy
3. 三月 20, 2013 2:37:36 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
4. INFO: Loading XML bean definitions from class path resource [resource/aop.xml]
5. 三月 20, 2013 2:37:36 下午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
6. INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@157985: defining beans [book,beforeMethodBean,afterMethodBean,throwException,bookProxy]; root of factory hierarchy
7. ---------------------
8. Before  Method
9. --------------------
10. Book name Effective java
11. -------------------
12. After  method
13. ---------------------
14. Before  Method
15. --------------------
16. Book URL www.google.cn
17. -------------------
18. After  method
19. ----------------------
20. Before  Method
21. --------------------
22. after Throwing  Exception

三月 20, 2013 2:37:36 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@eb67e8: startup date [Wed Mar 20 14:37:36 CST 2013]; root of context hierarchy
三月 20, 2013 2:37:36 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [resource/aop.xml]
三月 20, 2013 2:37:36 下午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@157985: defining beans [book,beforeMethodBean,afterMethodBean,throwException,bookProxy]; root of factory hierarchy
---------------------
Before  Method
--------------------
Book name Effective java
-------------------
After  method
---------------------
Before  Method
--------------------
Book URL www.google.cn
-------------------
After  method
----------------------
Before  Method
--------------------
after Throwing  Exception

4：Around  advice

这个advice 联合了上面的三个advices，在方法执行期间执行，创建一个类实现MethodInterceptor接口，需要在方法中执行Object result = methodInvocation.proceed();方法才能得到执行，否则方法不会执行。

类如下：

1. package com.myapp.core.aop.advice;
2. import java.util.Arrays;
3. import org.aopalliance.intercept.MethodInterceptor;
4. import org.aopalliance.intercept.MethodInvocation;
5. public class AroundMethod  implements MethodInterceptor{
6. @Override
7. public Object invoke(MethodInvocation methodInvocation) throws Throwable {
8. // TODO Auto-generated method stub
9. System.out.println("method  name:" + methodInvocation.getMethod().getName());
10. System.out.println("method  arguments" + Arrays.toString(methodInvocation.getArguments()));
11. System.out.println("Around  method : before ");
12. try{
13. Object result = methodInvocation.proceed();
14. System.out.println("Around method : after ");
15. return  result;
16. }catch(IllegalArgumentException e){
17. System.out.println("Around method : throw  an  exception ");
18. throw  e;
19. }
20. }
21. }

package com.myapp.core.aop.advice;

import java.util.Arrays;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;

public class AroundMethod  implements MethodInterceptor{

	@Override
	public Object invoke(MethodInvocation methodInvocation) throws Throwable {
		// TODO Auto-generated method stub

		System.out.println("method  name:" + methodInvocation.getMethod().getName());

		System.out.println("method  arguments" + Arrays.toString(methodInvocation.getArguments()));

		System.out.println("Around  method : before ");

		try{

			Object result = methodInvocation.proceed();

			System.out.println("Around method : after ");
			return  result;

		}catch(IllegalArgumentException e){

			System.out.println("Around method : throw  an  exception ");
			throw  e;
		}
	}

}

配置文件如下：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <beans xmlns="http://www.springframework.org/schema/beans"
3. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4. xsi:schemaLocation="http://www.springframework.org/schema/beans
5. http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
6. <!-- more bean definitions for data access objects go here -->
7. <bean id="book" class="com.myapp.core.aop.advice.Book">
8. <property name="name" value="Effective java" />
9. <property name="url" value="www.google.cn"/>
10. <property name="pages" value="300" />
11. </bean>
12. <bean id="aroundMethod"  class="com.myapp.core.aop.advice.AroundMethod" />
13. <bean id="bookProxy" class="org.springframework.aop.framework.ProxyFactoryBean" >
14. <property name="target" ref="book"/>
15. <property name="interceptorNames">
16. <list>
17. <value>aroundMethod</value>
18. </list>
19. </property>
20. </bean>
21. </beans>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

  <!-- more bean definitions for data access objects go here -->

    <bean id="book" class="com.myapp.core.aop.advice.Book">
	    <property name="name" value="Effective java" />
	    <property name="url" value="www.google.cn"/>
	    <property name="pages" value="300" />
    </bean>

    <bean id="aroundMethod"  class="com.myapp.core.aop.advice.AroundMethod" />

    <bean id="bookProxy" class="org.springframework.aop.framework.ProxyFactoryBean" >
     <property name="target" ref="book"/>

     <property name="interceptorNames">
       <list>

         <value>aroundMethod</value>
       </list>
     </property>

     </bean>
</beans>

测试结果：

1. 三月 20, 2013 3:02:19 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
2. INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@eb67e8: startup date [Wed Mar 20 15:02:19 CST 2013]; root of context hierarchy
3. 三月 20, 2013 3:02:19 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
4. INFO: Loading XML bean definitions from class path resource [resource/aop.xml]
5. 三月 20, 2013 3:02:19 下午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
6. INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@e29127: defining beans [book,aroundMethod,bookProxy]; root of factory hierarchy
7. ---------------------
8. method  name:printName
9. method  arguments[]
10. Around  method : before
11. Book name Effective java
12. Around method : after
13. ---------------------
14. method  name:printUrl
15. method  arguments[]
16. Around  method : before
17. Book URL www.google.cn
18. Around method : after
19. ----------------------
20. method  name:printThrowException
21. method  arguments[]
22. Around  method : before
23. Around method : throw  an  exception

三月 20, 2013 3:02:19 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@eb67e8: startup date [Wed Mar 20 15:02:19 CST 2013]; root of context hierarchy
三月 20, 2013 3:02:19 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [resource/aop.xml]
三月 20, 2013 3:02:19 下午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@e29127: defining beans [book,aroundMethod,bookProxy]; root of factory hierarchy
---------------------
method  name:printName
method  arguments[]
Around  method : before
Book name Effective java
Around method : after
---------------------
method  name:printUrl
method  arguments[]
Around  method : before
Book URL www.google.cn
Around method : after
----------------------
method  name:printThrowException
method  arguments[]
Around  method : before
Around method : throw  an  exception

around  advice得到实现。 over