at.chrl.callbacks.enhancer

Class ObjectCallbackEnhancer

java.lang.Object

at.chrl.callbacks.enhancer.CallbackClassFileTransformer

at.chrl.callbacks.enhancer.ObjectCallbackEnhancer

All Implemented Interfaces:

ClassFileTransformer

public class ObjectCallbackEnhancer
extends CallbackClassFileTransformer

Field Summary

Fields

Modifier and Type	Field and Description
static String	FIELD_NAME_CALLBACKS Field name for callbacks map
static String	FIELD_NAME_CALLBACKS_LOCK Field name for synchronizer

Constructor Summary

Constructors

Constructor and Description
ObjectCallbackEnhancer()

Method Summary

Modifier and Type	Method and Description
protected void	enhanceMethod(javassist.CtMethod method) Responsible for method enhancing, writing service calls to method.
protected boolean	isEnhanceable(javassist.CtMethod method) Checks if method is enhanceable.
protected byte[]	transformClass(ClassLoader loader, byte[] clazzBytes) Does actual transformation
protected String	writeAfterMethod(javassist.CtMethod method, int paramLength, String listenerFieldName) Writes code that will be inserted after method
protected String	writeBeforeMethod(javassist.CtMethod method, int paramLength, String listenerFieldName) Code that is added in the begining of the method
protected void	writeEnhancedObjectImpl(javassist.CtClass clazz) Implements on class

Methods inherited from class at.chrl.callbacks.enhancer.CallbackClassFileTransformer

transform

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

FIELD_NAME_CALLBACKS

public static final String FIELD_NAME_CALLBACKS

Field name for callbacks map

See Also:

Constant Field Values

FIELD_NAME_CALLBACKS_LOCK

public static final String FIELD_NAME_CALLBACKS_LOCK

Field name for synchronizer

See Also:

Constant Field Values

Constructor Detail

ObjectCallbackEnhancer

public ObjectCallbackEnhancer()

Method Detail

transformClass

protected byte[] transformClass(ClassLoader loader,
                                byte[] clazzBytes)
                         throws Exception

Does actual transformation

Specified by:

transformClass in class CallbackClassFileTransformer

Parameters:

loader - class loader

clazzBytes - class bytecode

Returns:

transformed class bytecode

Throws:

Exception - is something went wrong

enhanceMethod

protected void enhanceMethod(javassist.CtMethod method)
                      throws javassist.CannotCompileException,
                             javassist.NotFoundException,
                             ClassNotFoundException

Responsible for method enhancing, writing service calls to method.

Parameters:

method - Method that has to be edited

Throws:

javassist.CannotCompileException - if something went wrong

javassist.NotFoundException - if something went wrong

ClassNotFoundException - if something went wrong

writeBeforeMethod

protected String writeBeforeMethod(javassist.CtMethod method,
                                   int paramLength,
                                   String listenerFieldName)
                            throws javassist.NotFoundException,
                                   javassist.CannotCompileException

Code that is added in the begining of the method

Parameters:

method - method that should be edited

paramLength - Lenght of methods parameters

listenerFieldName - Listener class that is used for method

Returns:

code that will be inserted before method

Throws:

javassist.NotFoundException - if something went wrong

javassist.CannotCompileException

writeAfterMethod

protected String writeAfterMethod(javassist.CtMethod method,
                                  int paramLength,
                                  String listenerFieldName)
                           throws javassist.NotFoundException

Writes code that will be inserted after method

Parameters:

method - method to edit

paramLength - lenght of method paramenters

listenerFieldName - method listener

Returns:

actual code that should be inserted

Throws:

javassist.NotFoundException - if something went wrong

writeEnhancedObjectImpl

protected void writeEnhancedObjectImpl(javassist.CtClass clazz)
                                throws javassist.NotFoundException,
                                       javassist.CannotCompileException

Implements on class

Parameters:

clazz - class to edit

Throws:

javassist.NotFoundException - if something went wrong

javassist.CannotCompileException - if something went wrong

isEnhanceable

protected boolean isEnhanceable(javassist.CtMethod method)

Checks if method is enhanceable. It should be marked with ObjectCallback annotation, be not native and not abstract

Parameters:

method - method to check

Returns:

check result