Spring annotation & XML to implement AOP Programming

Implement AOP programming using spring annotations and XML
To implement the AOP programming annotation method, follow these steps:

1) Introduce jar files related to aop first (excellent aspectj aop components)

Spring-aop-3.2.5.RELEASE.jar [spring3.2 source code]

Aopalliance. jar [spring2.5 source code/lib/aopalliance]

Aspectjweaver. jar [spring2.5 source code/lib/aspectj] or [aspectj-1.8.2lib]

Aspectjrt. jar [spring2.5 source code/lib/aspectj] or [aspectj-1.8.2lib]

Note:: The jar file of spring2.5 may be used if JDK is used.

You need to upgrade the aspectj component by providing the jar file in the aspectj-1.8.2 version.

2) introduce the aop namespace in bean. xml (search xmln: aop in the document)

3) Enable the aop Annotation

4) use annotations

@ Aspect: specify a class as the partition class.

@ Pointcut (execution (* cn. itcast. e_aop_anno. *. * (..) specifies the entry point expression

 

@ Before (pointCut _ () pre-notification: executed Before the target method

@ After (pointCut _ () post-Notification: After the target method is executed (always executed)

@ AfterReturning (pointCut _ () notification after return: execution before the execution method ends (exception not executed)

@ AfterThrowing (pointCut _ () exception notification: Execute when an exception occurs

@ Around (pointCut _ () surround notification: Surround target method execution

Case:

1) IUserDao Interface

 

package cn.itcast.aop_anno;public interface IUserDao {public void save();}

2) UserDao implements the IUserDao Interface

 

 

Package cn. itcast. aop_anno; import org. springframework. stereotype. component; @ Component // IOC container management public class UserDao implements IUserDao {public void save () {System. out. println (core business! Save );}}

3) face-cutting Aop

 

 

Package cn. itcast. aop_anno; import org. aspectj. lang. annotation. after; import org. aspectj. lang. annotation. aspect; import org. aspectj. lang. annotation. before; import org. aspectj. lang. annotation. pointcut; import org. springframework. stereotype. component; @ Component @ Aspect // specify the current class as the face-cutting class public class Aop {// face-cutting class @ Pointcut (execution (* cn. itcast. aop_anno. *. *(..))) // cut surface expression public void pointCut _ () {}@ Before (pointCut _ () // intercept the method specified by the cut surface expression .. public void before () {System. out. println (before) ;}@ After (pointCut _ () public void after () {System. out. println (after );}}

 

4) bean. xml configuration --> introduce the namespace (search xmln: aop in the document)

--> Enable annotation Scanning

--> Enable annotation aop Annotation

 

 

5) test App ---> the returned value must be the IUserdao interface.

 

package cn.itcast.aop_anno;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class App {ApplicationContext ac=new ClassPathXmlApplicationContext(cn/itcast/aop_anno/bean.xml);@Testpublic void test(){IUserDao userdao=(IUserDao) ac.getBean(userDao);userdao.save();}}

Test results:

 

------------------------------------------ Deep understanding ----------------------------------------

1) if UserDao does not implement the IUserDao Interface

The test class is changed:

 

package cn.itcast.aop_anno;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class App {ApplicationContext ac=new ClassPathXmlApplicationContext(cn/itcast/aop_anno/bean.xml);@Testpublic void test(){UserDao userdao=(UserDao) ac.getBean(userDao);System.out.println(userdao.getClass());userdao.save();}}

Test result: --> the returned result must be UserDao, that is, the class is not an interface.

 

 

To implement AOP programming in xml mode, follow these steps:

 

 

Implement aop programming in Xml:

1) introduce the jar file [aop-related jar, 4]

2) introduce the aop namespace

3) aop Configuration

* Configure face-cutting classes (classes formed by repeated code execution)

* Aop Configuration

Which methods to intercept/apply the notification code after the method is intercepted?

Case:

IUserDao, UserDao, and AOP classes are the same as above, ---------> just remove the annotation ..

1) bean. xml file configuration

 

 
        
          
          
          
                  
                  
  Aspect ref = "aop">        
 

2) test apps

 

 

package cn.itcast.aop_xml;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class App {ApplicationContext ac=new ClassPathXmlApplicationContext(cn/itcast/aop_xml/bean.xml);@Testpublic void test(){IUserDao userdao= (IUserDao) ac.getBean(userDao);System.out.println(userdao.getClass());userdao.save();}}

Running result: