Spring Framework example source code file (OC4JLoadTimeWeaver.java)

This example Spring Framework source code file (OC4JLoadTimeWeaver.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

classloader, classloader, loadtimeweaver, oc4jclasspreprocessoradapter, oc4jclasspreprocessoradapter, oc4jloadtimeweaver, oc4jloadtimeweaver, transformer, transformer

The Spring Framework OC4JLoadTimeWeaver.java source code

/*
 * Copyright 2002-2007 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
 *
 *      http://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.oc4j;

import java.lang.instrument.ClassFileTransformer;

import oracle.classloader.util.ClassLoaderUtilities;

import org.springframework.instrument.classloading.LoadTimeWeaver;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;

/**
 * {@link LoadTimeWeaver} implementation for OC4J's instrumentable ClassLoader.
 *
 * <p>NOTE: Requires Oracle OC4J version 10.1.3.1 or higher.
 *
 * <p>Many thanks to Mike Keith
 * for his assistance.
 *
 * @author Costin Leau
 * @author Juergen Hoeller
 * @since 2.0
 */
public class OC4JLoadTimeWeaver implements LoadTimeWeaver {

	private final ClassLoader classLoader;


	/**
	 * Creates a new instance of thie {@link OC4JLoadTimeWeaver} class
	 * using the default {@link ClassLoader class loader}.
	 * @see org.springframework.util.ClassUtils#getDefaultClassLoader() 
	 */
	public OC4JLoadTimeWeaver() {
		this(ClassUtils.getDefaultClassLoader());
	}
	
	/**
	 * Creates a new instance of the {@link OC4JLoadTimeWeaver} class
	 * using the supplied {@link ClassLoader}.
	 * @param classLoader the <code>ClassLoader to delegate to for weaving
	 */
	public OC4JLoadTimeWeaver(ClassLoader classLoader) {
		Assert.notNull(classLoader, "ClassLoader must not be null");
		this.classLoader = classLoader;
	}


	public void addTransformer(ClassFileTransformer transformer) {
		Assert.notNull(transformer, "Transformer must not be null");
		// Since OC4J 10.1.3's PolicyClassLoader is going to be removed,
		// we rely on the ClassLoaderUtilities API instead.
		OC4JClassPreprocessorAdapter processor = new OC4JClassPreprocessorAdapter(transformer);
		ClassLoaderUtilities.addPreprocessor(this.classLoader, processor);
	}

	public ClassLoader getInstrumentableClassLoader() {
		return this.classLoader;
	}

	public ClassLoader getThrowawayClassLoader() {
		return ClassLoaderUtilities.copy(this.classLoader);
	}

}