org.springframework.instrument.classloading.LoadTimeWeaver Maven / Gradle / Ivy
/*
* Copyright 2002-2012 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.instrument.classloading;
import java.lang.instrument.ClassFileTransformer;
/**
* Defines the contract for adding one or more
* {@link ClassFileTransformer ClassFileTransformers} to a {@link ClassLoader}.
*
* Implementations may operate on the current context {@code ClassLoader}
* or expose their own instrumentable {@code ClassLoader}.
*
* @author Rod Johnson
* @author Costin Leau
* @since 2.0
* @see java.lang.instrument.ClassFileTransformer
*/
public interface LoadTimeWeaver {
/**
* Add a {@code ClassFileTransformer} to be applied by this
* {@code LoadTimeWeaver}.
* @param transformer the {@code ClassFileTransformer} to add
*/
void addTransformer(ClassFileTransformer transformer);
/**
* Return a {@code ClassLoader} that supports instrumentation
* through AspectJ-style load-time weaving based on user-defined
* {@link ClassFileTransformer ClassFileTransformers}.
*
May be the current {@code ClassLoader}, or a {@code ClassLoader}
* created by this {@link LoadTimeWeaver} instance.
* @return the {@code ClassLoader} which will expose
* instrumented classes according to the registered transformers
*/
ClassLoader getInstrumentableClassLoader();
/**
* Return a throwaway {@code ClassLoader}, enabling classes to be
* loaded and inspected without affecting the parent {@code ClassLoader}.
*
Should not return the same instance of the {@link ClassLoader}
* returned from an invocation of {@link #getInstrumentableClassLoader()}.
* @return a temporary throwaway {@code ClassLoader}; should return
* a new instance for each call, with no existing state
*/
ClassLoader getThrowawayClassLoader();
}