1 Reply Latest reply on Nov 3, 2004 1:42 PM by bill.burke

    ClassCastException in caller side advices

    skellen
    skellen Nov 3, 2004 1:42 PM

      Hi,

      I have the following aspect class:

      public class CounterAspect {
 private int counter;
 ... some other fields ...

 public Object start( Invocation invocation ) throws Throwable {
 counter = 0;
 return invocation.invokeNext();
 }

 public Object count( Invocation invocation ) throws Throwable {
 counter += 1;
 ... some log4j stuff ...
 return invocation.invokeNext();
 }
}


      and I try to advice IndexWriter class form Jakarta Lucene: 

      <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<aop>
 <pointcut
 name="IndexWriter.start"
 expr="call(org.apache.lucene.index.IndexWriter->new(..))"/>

 <pointcut
 name="IndexWriter.count"
 expr="call(* org.apache.lucene.index.IndexWriter->addDocument(..))"/>

 <aspect
 class="CounterAspect"
 scope="PER_INSTANCE"/>

 <bind pointcut="IndexWriter.start">
 <advice name="start"
 aspect="CounterAspect"/>
 </bind>

 <bind pointcut="IndexWriter.count">
 <advice name="count"
 aspect="CounterAspect"/>
 </bind>

</aop>


      When one of the IndexWriter.addDocument(..) methods is called I get an exception: 

      Caused by: java.lang.ClassCastException: org.apache.lucene.index.IndexWriter
 at org.jboss.aop.advice.PerInstanceAdvice.invoke(PerInstanceAdvice.java:46)
 ...


      As I can see in the JBossAOP source, it is caused by casting target object (IndexWriter) to Advised type. Why JBossAOP assumes target object implements this interface (but doesn't modify original class)? It is _caller_ side pointcut, so I think only caller side should be affected.


      Best ragards,

      Szczepan Kuzniarz

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        • 1. ClassCastException in caller side advices
          bill.burke
          bill.burke Nov 3, 2004 1:42 PM (in response to skellen)

          Hi,

          I have the following aspect class:

          public class CounterAspect {
 private int counter;
 ... some other fields ...

 public Object start( Invocation invocation ) throws Throwable {
 counter = 0;
 return invocation.invokeNext();
 }

 public Object count( Invocation invocation ) throws Throwable {
 counter += 1;
 ... some log4j stuff ...
 return invocation.invokeNext();
 }
}


          and I try to advice IndexWriter class form Jakarta Lucene: 

          <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<aop>
 <pointcut
 name="IndexWriter.start"
 expr="call(org.apache.lucene.index.IndexWriter->new(..))"/>

 <pointcut
 name="IndexWriter.count"
 expr="call(* org.apache.lucene.index.IndexWriter->addDocument(..))"/>

 <aspect
 class="CounterAspect"
 scope="PER_INSTANCE"/>

 <bind pointcut="IndexWriter.start">
 <advice name="start"
 aspect="CounterAspect"/>
 </bind>

 <bind pointcut="IndexWriter.count">
 <advice name="count"
 aspect="CounterAspect"/>
 </bind>

</aop>


          When one of the IndexWriter.addDocument(..) methods is called I get an exception: 

          Caused by: java.lang.ClassCastException: org.apache.lucene.index.IndexWriter
 at org.jboss.aop.advice.PerInstanceAdvice.invoke(PerInstanceAdvice.java:46)
 ...


          As I can see in the JBossAOP source, it is caused by casting target object (IndexWriter) to Advised type. Why JBossAOP assumes target object implements this interface (but doesn't modify original class)? It is _caller_ side pointcut, so I think only caller side should be affected.


          Best ragards,

          Szczepan Kuzniarz

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