AOP and Spring

[Julio leopard banderas]

Hey,

i heared about AOP in Spring, but i still confusing the concept of AOP and his utility in Spring,
can anyone give us the concept and the utility to use AOP ?

thanks

[Shailesh Phatak]

Julio leopard banderas wrote:Hey,

i heared about AOP in Spring, but i still confusing the concept of AOP and his utility in Spring,
can anyone give us the concept and the utility to use AOP ?

thanks

Hi Julio,

I too learning AOP in Spring these days, I can help you in understanding what AOP is and its utility in any web application.

Suppose you have a class say Audience and in that class you have methods say
1) takeSeats()
2) switchOffMobile()
3) appluad()

Also you have a pojo class say Compititor which is having fields Name and Instrument

we have a class ShowStarting which look like this once you initialized bean for Competitor and Audience

       Competitor com=(Competitor)appCont.getBean("comp");
      //System.out.println("Show is starting");
        Audience aud=(Audience)appCont.getBean("aud");
       /* Cross Cutting Concerns  which is common at many place and should not be a part of you business logic */
        aud.takeSeats();   
        aud.turnOffCellPhones();

        System.out.println("Presenting our first compititor:: "+com.getName());
        System.out.println("And He Plays:: "+com.getInstrument());

        System.out.println("You Like It?? ");

        aud.appluad(); // Cross Cutting Concerns
    

You can eliminate these cross cutting concerns and allow Spring to handle these. This is one of the advantage of AOP.
These cross cutting concerns you have to write in an xml to tell spring when and where to call them.

[Hussein Baghdadi]

You can find here some some good materials about AOP:
JBoss AOP and Aspect-oriented Programming.

[Hussein Baghdadi]

Shailesh Phatak wrote:

Julio leopard banderas wrote:Hey,

i heared about AOP in Spring, but i still confusing the concept of AOP and his utility in Spring,
can anyone give us the concept and the utility to use AOP ?

thanks

Hi Julio,

I too learning AOP in Spring these days, I can help you in understanding what AOP is and its utility in any web application.

Suppose you have a class say Audience and in that class you have methods say
1) takeSeats()
2) switchOffMobile()
3) appluad()

Also you have a pojo class say Compititor which is having fields Name and Instrument

we have a class ShowStarting which look like this once you initialized bean for Competitor and Audience

       Competitor com=(Competitor)appCont.getBean("comp");
      //System.out.println("Show is starting");
        Audience aud=(Audience)appCont.getBean("aud");
       /* Cross Cutting Concerns  which is common at many place and should not be a part of you business logic */
        aud.takeSeats();   
        aud.turnOffCellPhones();

        System.out.println("Presenting our first compititor:: "+com.getName());
        System.out.println("And He Plays:: "+com.getInstrument());

        System.out.println("You Like It?? ");

        aud.appluad(); // Cross Cutting Concerns
    

You can eliminate these cross cutting concerns and allow Spring to handle these. This is one of the advantage of AOP.
These cross cutting concerns you have to write in an xml to tell spring when and where to call them.

I'm not sure how your example is going to explain AOP but maybe it is just me.

It is worth noting that XML isn't the only way to configure your Aspects, you can also use annotations.

[Bill Gorder]

Spring uses aspects behind the scenes to do many of the things you probably use. Any cross cutting concern is a good candidate such as security, logging, and transactions. You can leverage spring-aop to create your own aspects or use AspectJ with Spring for even more powerful constructs. As was said with Spring AOP you can take an annotation or xml configuration approach. When using AspectJ you can also use the AspectJ language (to write .aj files).

One example of how this is used is the @Transactional annotation. Typically there would be a lot of boiler plate around creating transactions, committing them and rolling them back. Some of this would have to happen before the database operation and some of it after. AspectJ is used to inject code before and after a method annotated with @Transactional so that you no longer have to do this things every single time you wish to use transactions.