Spring Framework example source code file (SpringPersistenceUnitInfo.java)

This example Spring Framework source code file (SpringPersistenceUnitInfo.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

cannot, cannot, classfiletransformeradapter, classloader, classloader, decoratingclassloader, decoratingclassloader, illegalstateexception, loadtimeweaver, loadtimeweaver, mutablepersistenceunitinfo, springpersistenceunitinfo, string

The Spring Framework SpringPersistenceUnitInfo.java source code

/*
 * Copyright 2002-2008 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.orm.jpa.persistenceunit;

import javax.persistence.spi.ClassTransformer;

import org.springframework.core.DecoratingClassLoader;
import org.springframework.instrument.classloading.LoadTimeWeaver;
import org.springframework.instrument.classloading.SimpleThrowawayClassLoader;
import org.springframework.util.Assert;

/**
 * Subclass of {@link MutablePersistenceUnitInfo} that adds instrumentation hooks based on
 * Spring's {@link org.springframework.instrument.classloading.LoadTimeWeaver} abstraction.
 *
 * <p>This class is restricted to package visibility, in contrast to its superclass.
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @author Costin Leau
 * @since 2.0
 * @see PersistenceUnitManager
 */
class SpringPersistenceUnitInfo extends MutablePersistenceUnitInfo {

	private LoadTimeWeaver loadTimeWeaver;

	private ClassLoader classLoader;


	/**
	 * Initialize this PersistenceUnitInfo with the LoadTimeWeaver SPI interface
	 * used by Spring to add instrumentation to the current class loader.
	 */
	public void init(LoadTimeWeaver loadTimeWeaver) {
		Assert.notNull(loadTimeWeaver, "LoadTimeWeaver must not be null");
		this.loadTimeWeaver = loadTimeWeaver;
		this.classLoader = loadTimeWeaver.getInstrumentableClassLoader();
	}

	/**
	 * Initialize this PersistenceUnitInfo with the current class loader
	 * (instead of with a LoadTimeWeaver).
	 */
	public void init(ClassLoader classLoader) {
		Assert.notNull(classLoader, "ClassLoader must not be null");
		this.classLoader = classLoader;
	}


	/**
	 * This implementation returns the LoadTimeWeaver's instrumentable ClassLoader,
	 * if specified.
	 */
	public ClassLoader getClassLoader() {
		return this.classLoader;
	}

	/**
	 * This implementation delegates to the LoadTimeWeaver, if specified.
	 */
	public void addTransformer(ClassTransformer classTransformer) {
		if (this.loadTimeWeaver == null) {
			throw new IllegalStateException("Cannot apply class transformer without LoadTimeWeaver specified");
		}
		this.loadTimeWeaver.addTransformer(new ClassFileTransformerAdapter(classTransformer));
	}

	/**
	 * This implementation delegates to the LoadTimeWeaver, if specified.
	 */
	public ClassLoader getNewTempClassLoader() {
		ClassLoader tcl = (this.loadTimeWeaver != null ? this.loadTimeWeaver.getThrowawayClassLoader() :
				new SimpleThrowawayClassLoader(this.classLoader));
		String packageToExclude = getPersistenceProviderPackageName();
		if (packageToExclude != null && tcl instanceof DecoratingClassLoader) {
			((DecoratingClassLoader) tcl).excludePackage(packageToExclude);
		}
		return tcl;
	}

}