JBOSSAOP学习笔记-依赖注入

 package org.jboss.aspects;

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;

@Target({ElementType.FIELD})
public @interface Inject {}

 package org.jboss.aspects;

import org.jboss.aop.joinpoint.*;
import java.lang.reflect.Field;
import javax.transaction.TransactionManager;
import org.jboss.tm.TxManager;

public InjectTMAspect
{
   PRivate TransactionManager tm = TxManager.getInstance();

   public Object access(FieldReadInvocation invocation)
       throws Throwable
   {
      return tm;
   }

   public Object access(FieldWriteInvocation invocation)
       throws Throwable
   {
      throw new RuntimeException(
          "Setting an @Injected variable is illegal");
   }
}

 <aop>
  <aspect class="org.jboss.aspects.InjectTMAspect"/>

  <bind pointcut="field(javax.transaction.TransactionManager *->@org.jboss.aspects.Inject)">
     <advice name="access"
             aspect="org.jboss.aspects.InjectTMAspect"/>
  </bind>
</aop>

 import javax.transaction.TransactionManager;
import org.jboss.aspects.Inject;

public class MyTransactionalCache
{
   @Inject private TransactionManager tm;
...
}