ClassFileTransformers. These transformers can instrument (or weave) the byte code of classes loaded through this class loader to alter their behavior. Currently only
WebappClassLoaderBaseimplements this interface. This allows web application frameworks or JPA providers bundled with a web application to instrument web application classes as necessary.
You should always program against the methods of this interface
(whether using reflection or otherwise). The methods in
WebappClassLoaderBase are protected by the default security
manager if one is in use.
- 8.0, 7.0.64
Method SummaryModifier and TypeMethodDescription
voidAdds the specified class file transformer to this class loader.Returns a copy of this class loader without any class file transformers.
voidRemoves the specified class file transformer from this class loader.
(ClassFileTransformer transformer)Adds the specified class file transformer to this class loader. The transformer will then be able to instrument the bytecode of any classes loaded by this class loader after the invocation of this method.
transformer- The transformer to add to the class loader
IllegalArgumentException- if the transformer is null.
(ClassFileTransformer transformer)Removes the specified class file transformer from this class loader. It will no longer be able to instrument the byte code of any classes loaded by the class loader after the invocation of this method. However, any classes already instrumented by this transformer before this method call will remain in their instrumented state.
transformer- The transformer to remove
copyWithoutTransformersClassLoader copyWithoutTransformers()Returns a copy of this class loader without any class file transformers. This is a tool often used by Java Persistence API providers to inspect entity classes in the absence of any instrumentation, something that can't be guaranteed within the context of a
The returned class loader's resource cache will have been cleared so that classes already instrumented will not be retained or returned.
- the transformer-free copy of this class loader.