Class ReflectiveLoadTimeWeaver
- java.lang.Object
- org.springframework.instrument.classloading.ReflectiveLoadTimeWeaver
- All Implemented Interfaces:
LoadTimeWeaver
public class ReflectiveLoadTimeWeaver extends Object implements LoadTimeWeaver
LoadTimeWeaverwhich 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 theLoadTimeWeaverinterface):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
TomcatInstrumentableClassLoaderfor 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 voidaddTransformer(ClassFileTransformer transformer)Add aClassFileTransformerto be applied by thisLoadTimeWeaver.ClassLoadergetInstrumentableClassLoader()Return aClassLoaderthat supports instrumentation through AspectJ-style load-time weaving based on user-definedClassFileTransformers.ClassLoadergetThrowawayClassLoader()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- theClassLoaderto delegate to for weaving (must support the required weaving methods).- Throws:
IllegalStateException- if the suppliedClassLoaderdoes not support the required weaving methods
Method Detail
addTransformer
public void addTransformer(ClassFileTransformer transformer)
Description copied from interface:LoadTimeWeaverAdd aClassFileTransformerto be applied by thisLoadTimeWeaver.- Specified by:
addTransformerin interfaceLoadTimeWeaver- Parameters:
transformer- theClassFileTransformerto add
getInstrumentableClassLoader
public ClassLoader getInstrumentableClassLoader()
Description copied from interface:LoadTimeWeaverReturn aClassLoaderthat supports instrumentation through AspectJ-style load-time weaving based on user-definedClassFileTransformers.May be the current
ClassLoader, or aClassLoadercreated by thisLoadTimeWeaverinstance.- Specified by:
getInstrumentableClassLoaderin interfaceLoadTimeWeaver- Returns:
- the
ClassLoaderwhich will expose instrumented classes according to the registered transformers
getThrowawayClassLoader
public ClassLoader getThrowawayClassLoader()
Description copied from interface:LoadTimeWeaverReturn a throwawayClassLoader, enabling classes to be loaded and inspected without affecting the parentClassLoader.Should not return the same instance of the
ClassLoaderreturned from an invocation ofLoadTimeWeaver.getInstrumentableClassLoader().- Specified by:
getThrowawayClassLoaderin interfaceLoadTimeWeaver- Returns:
- a temporary throwaway
ClassLoader; should return a new instance for each call, with no existing state