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/* * 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}. * * <p>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}. * <p>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}. * <p>Should <i>not</i> 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(); }