[jboss-dev-forums] [Design of AOP on JBoss (Aspects/JBoss)] - Creation of method tables in ClassAdvisor

[jaikiran]

Need some input on a couple of things in the org.jboss.aop.ClassAdvisor http://anonsvn.jboss.org/repos/jbossas/projects/aop/branches/Branch_2_1/aop/src/main/java/org/jboss/aop/ClassAdvisor.java. During initialization and creation of method tables, the ClassAdvisor in it's addDeclaredMethod does this:


  | protected void addDeclaredMethods(Class<?> superclass) throws Exception
  |    {
  |       Method[] declaredMethods = superclass.getDeclaredMethods();
  |       for (int i = 0; i < declaredMethods.length; i++)
  |       {
  |          if (ClassAdvisor.isAdvisable(declaredMethods[ i]))
  |          {
  |             long hash = MethodHashing.methodHash(declaredMethods[ i]);
  |             advisedMethods.put(hash, declaredMethods[ i]);
  |             try
  |             {
  |                Method m = declaredMethods[ i];
  |                Method un = superclass.getDeclaredMethod(ClassAdvisor.notAdvisedMethodName(superclass.getName(),
  |                m.getName()),
  |                m.getParameterTypes());
  |                un.setAccessible(true);
  |                unadvisedMethods.put(hash, un);
  |             }
  |             catch (NoSuchMethodException ignored)
  |             {
  |             }
  |          }
  |       }
  |    }
  | 
  |   public static String notAdvisedMethodName(String className,
  |                                              String methodName)
  |    {
  |       return className.replace('.', '$') + "$" + methodName +
  |       NOT_TRANSFORMABLE_SUFFIX;
  |    }
  | 
  |    /**
  |     * Suffix added to unadvised methods.
  |     */
  |    public static final String NOT_TRANSFORMABLE_SUFFIX = "$aop";
  | 
  | 
  | 

Assuming i have this expression:


  | <domain name="XXX" extends="YYY" inheritBindings="true">
  |       <bind pointcut="execution(public * *->*(..))">
  |       ...
  |       </bind>
  | 


  | package org.myapp;
  | 
  | 
  | public class SomeClass
  | {
  |  public void method1()
  |  {
  |    ..
  |   }
  |   
  |  public void method2()
  |  {
  |   ..
  |  }
  | }
  | 
1) So the addDeclaredMethod piece of code, above, is going to generate for each method an "unadvised method name" as:


  | org$myapp$SomeClass$method1$aop
  | org$myapp$SomeClass$method2$aop
  | 
and later on when the 

  | superclass.getDeclaredMethod(ClassAdvisor.notAdvisedMethodName(superclass.getName(), m.getName()),m.getParameterTypes());
  | 
is called it's always going to throw a NoSuchMethodException, isn't it?

What is the purpose of this code? I guess, there is some specific scenario where this comes into picture

2) The MethodHashing.methodHash() does some very specific/involved logic. How is it different from a normal method.hashCode()?

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