Class ReflectiveLoadTimeWeaver
- java.lang.Object
- org.springframework.instrument.classloading.ReflectiveLoadTimeWeaver
- All Implemented Interfaces:
LoadTimeWeaver
public class ReflectiveLoadTimeWeaver extends Object implements LoadTimeWeaver
LoadTimeWeaver
which uses reflection to delegate to an underlying ClassLoader with well-known transformation hooks. The underlying ClassLoader is expected to support the following weaving methods (as defined in theLoadTimeWeaver
interface):public void addTransformer(java.lang.instrument.ClassFileTransformer)
: for registering the given ClassFileTransformer on this ClassLoaderpublic ClassLoader getThrowawayClassLoader()
: for obtaining a throwaway class loader for this ClassLoader (optional; ReflectiveLoadTimeWeaver will fall back to a SimpleThrowawayClassLoader if that method isn't available)
Please note that the above methods must reside in a class that is publicly accessible, although the class itself does not have to be visible to the application's class loader.
The reflective nature of this LoadTimeWeaver is particularly useful when the underlying ClassLoader implementation is loaded in a different class loader itself (such as the application server's class loader which is not visible to the web application). There is no direct API dependency between this LoadTimeWeaver adapter and the underlying ClassLoader, just a 'loose' method contract.
This is the LoadTimeWeaver to use in combination with Spring's
TomcatInstrumentableClassLoader
for Tomcat 5.0+ as well as with the Resin application server version 3.1+.- Since:
- 2.0
- Author:
- Costin Leau, Juergen Hoeller
- See Also:
addTransformer(java.lang.instrument.ClassFileTransformer)
,getThrowawayClassLoader()
,SimpleThrowawayClassLoader
,TomcatInstrumentableClassLoader
Constructor Summary
Constructors Constructor Description ReflectiveLoadTimeWeaver()
Create a new ReflectiveLoadTimeWeaver for the current context class loader, which needs to support the required weaving methods.ReflectiveLoadTimeWeaver(ClassLoader classLoader)
Create a new SimpleLoadTimeWeaver for the given class loader.
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
addTransformer(ClassFileTransformer transformer)
Add aClassFileTransformer
to be applied by thisLoadTimeWeaver
.ClassLoader
getInstrumentableClassLoader()
Return aClassLoader
that supports instrumentation through AspectJ-style load-time weaving based on user-definedClassFileTransformers
.ClassLoader
getThrowawayClassLoader()
Return a throwawayClassLoader
, enabling classes to be loaded and inspected without affecting the parentClassLoader
.
Constructor Detail
ReflectiveLoadTimeWeaver
public ReflectiveLoadTimeWeaver()
Create a new ReflectiveLoadTimeWeaver for the current context class loader, which needs to support the required weaving methods.
ReflectiveLoadTimeWeaver
public ReflectiveLoadTimeWeaver(ClassLoader classLoader)
Create a new SimpleLoadTimeWeaver for the given class loader.- Parameters:
classLoader
- theClassLoader
to delegate to for weaving (must support the required weaving methods).- Throws:
IllegalStateException
- if the suppliedClassLoader
does not support the required weaving methods
Method Detail
addTransformer
public void addTransformer(ClassFileTransformer transformer)
Description copied from interface:LoadTimeWeaver
Add aClassFileTransformer
to be applied by thisLoadTimeWeaver
.- Specified by:
addTransformer
in interfaceLoadTimeWeaver
- Parameters:
transformer
- theClassFileTransformer
to add
getInstrumentableClassLoader
public ClassLoader getInstrumentableClassLoader()
Description copied from interface:LoadTimeWeaver
Return aClassLoader
that supports instrumentation through AspectJ-style load-time weaving based on user-definedClassFileTransformers
.May be the current
ClassLoader
, or aClassLoader
created by thisLoadTimeWeaver
instance.- Specified by:
getInstrumentableClassLoader
in interfaceLoadTimeWeaver
- Returns:
- the
ClassLoader
which will expose instrumented classes according to the registered transformers
getThrowawayClassLoader
public ClassLoader getThrowawayClassLoader()
Description copied from interface:LoadTimeWeaver
Return a throwawayClassLoader
, enabling classes to be loaded and inspected without affecting the parentClassLoader
.Should not return the same instance of the
ClassLoader
returned from an invocation ofLoadTimeWeaver.getInstrumentableClassLoader()
.- Specified by:
getThrowawayClassLoader
in interfaceLoadTimeWeaver
- Returns:
- a temporary throwaway
ClassLoader
; should return a new instance for each call, with no existing state