CODEWITHSUNDEEP
javaspringdependency-injectionaspectj
huahsin68
huahsin68

Reputation: 6989

How to inject property into Aspect logging class?

I am having trouble injecting a property into LoggingAspect class. Imaging I have an AspectJ class:

@Aspect
public class LoggingAspect {
   private IBoc theBo;

   /** getter and setter **/
}

This is the BOC:

public interface IBoc {
}

public class BocImpl implements IBoc {
}

and the Spring configuration for BOC:

<beans ...>
   <aop:aspectj-autoproxy/>

   <bean id="theBoc" class="org.huahsin.BocImpl"/>
</beans>

In applicationContext.xml file, I configure the AspectJ in this way:

<beans...>
   <bean id="theLog" class="org.huahsin.LoggingAspect">
      <property name="theBo" ref="theBoc"/>
   </bean>
</beans>

How could I inject theBo in LoggingAspect class?

Update on 17 Oct 2012

I found some clue here. If I remove the <aop:aspectj-autoproxy>, the member variable theBo in class LoggingAspect will not be null. If I have that code, theBo will be null.

Upvotes: 1

Views: 1704

Answers (1)

Paulius Matulionis
Paulius Matulionis

Reputation: 23413

Normally Spring is responsible for both creating and configuring beans. AspectJ aspects, however, are created by the AspectJ runtime. You need Spring to configure the aspect that AspectJ has created. For the most common case of singleton aspects such as yours LoggingAspect aspect above, AspectJ defines an aspectOf() method that returns the aspect instance. You can tell Spring to use the aspectOf() method as a factory method for obtaining the aspect instance.

For e.g.:

  <beans>      
      <bean name="loggingAspect"
        class="org.huahsin.LoggingAspect"
        factory-method="aspectOf">
        <property name="theBo" ref="theBoc"/>
      </bean>

      <bean id="theBoc" class="org.huahsin.BocImpl"/>
  </beans>

UPDATE:

Define factory method in your class:

@Aspect
public class LoggingAspect {

    private IBoc iBoc;

    private static LoggingAspect instance = new LoggingAspect();

    public static LoggingAspect aspectOf() {
        return instance;
    }

    public void setiBoc(IBoc iBoc) {
        this.iBoc = iBoc;
    }
}

Upvotes: 3

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