Ejemplo n.º 1
0
 /**
  * Entry point for instrumentation, invoked by the modified classloader for JVM <= 1.4x. For Java
  * 1.5 it is invoked by the agent interface of the JVM. Thus this method is invoked for each class
  * being loaded by the JVM. This does not imply that all classes are instrumented.
  *
  * @param loader the class loader attempting to load this class.
  * @param className class name of class being loaded
  * @param protectionDomain security protection domain
  * @param classfileBuffer
  * @param offset
  * @param length
  * @return null if the class is not instrumented (modified)
  */
 public static byte[] transform(
     ClassLoader loader,
     String className,
     ProtectionDomain protectionDomain,
     byte[] classfileBuffer,
     int offset,
     int length) {
   try {
     init();
     // Check to see if we already know this class loader or add it to the Javassist ClassPool
     // search path if
     // it's new. This is important in J2EE- and Servlet containers that have class loader
     // hierarchies
     if (!classLoaders.containsKey(
         loader)) { // <<< TODO: this is a weak hash map, will this really work as intended?
       classPool.insertClassPath(new LoaderClassPath(loader));
       classLoaders.put(loader, null);
     }
     // Parses the byte array into a CtClass instance.
     CtClass ctc = loadClass(classfileBuffer, offset, length);
     // transforms the class if it is of any interest to us.
     byte[] bb = findTypeAndTransform(ctc);
     // removes the CtClass from the pool to release memory
     ctc.detach();
     return bb;
   } catch (Throwable t) {
     Log.warning(
         "Exception during categorizeAndTransform of class "
             + className
             + ". The class will be ignored.",
         t);
     return null;
   }
 }
Ejemplo n.º 2
0
 private static void init() {
   if (!initialized) {
     initialized = true;
     Log.info("Usemon agent initialized");
   }
   // Bootstrap the publisher
   Registry.ensurePublisherAvailable();
 }
Ejemplo n.º 3
0
 private static byte[] findTypeAndTransform(CtClass javaClass)
     throws CannotCompileException, IOException, NotFoundException {
   int componentType = findComponentType(javaClass);
   ClassFile cf = javaClass.getClassFile();
   if (componentType != Info.COMPONENT_UNKNOWN && !cf.isInterface() && !cf.isAbstract()) {
     Log.info(
         javaClass.getName()
             + " is of type "
             + Info.TYPES[componentType]
             + " and will be instrumented");
     switch (componentType) {
       case Info.COMPONENT_SESSIONBEAN:
         return ComponentTransformer.transformSessionBean(javaClass);
       case Info.COMPONENT_ENTITYBEAN:
         return ComponentTransformer.transformEntityBean(javaClass);
       case Info.COMPONENT_MESSAGEDRIVENBEAN:
         return ComponentTransformer.transformMessageDrivenBean(javaClass);
       case Info.COMPONENT_CUSTOM:
         return ComponentTransformer.transformCustom(javaClass);
       case Info.COMPONENT_QUEUESENDER:
         return ComponentTransformer.transformQueueSender(javaClass);
       case Info.COMPONENT_SERVLET:
         return ComponentTransformer.transformServlet(javaClass);
       case Info.COMPONENT_SINGLETON:
         return ComponentTransformer.transformSingleton(javaClass);
       case Info.COMPONENT_TOPICPUBLISHER:
         return ComponentTransformer.transformTopicPublisher(javaClass);
       case Info.COMPONENT_SQLSTATEMENT:
         return ComponentTransformer.transformSQLStatement(javaClass);
       case Info.COMPONENT_SQLCONNECTION:
         return ComponentTransformer.transformSQLConnection(javaClass);
       default:
         return null;
     }
   }
   return null;
 }