Spring Framework example source code file (DefaultPersistenceUnitManager.java)

This example Spring Framework source code file (DefaultPersistenceUnitManager.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

datasource, default_persistence_xml_location, illegalstateexception, illegalstateexception, io, loadtimeweaver, mutablepersistenceunitinfo, net, network, no, no, persistenceunitinfo, persistenceunitinfo, persistenceunitpostprocessor, springpersistenceunitinfo, sql, string, string, util

The Spring Framework DefaultPersistenceUnitManager.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 java.io.IOException;
import java.net.URL;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import javax.persistence.PersistenceException;
import javax.persistence.spi.PersistenceUnitInfo;
import javax.sql.DataSource;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ResourceLoaderAware;
import org.springframework.context.weaving.LoadTimeWeaverAware;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternUtils;
import org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver;
import org.springframework.instrument.classloading.LoadTimeWeaver;
import org.springframework.jdbc.datasource.lookup.DataSourceLookup;
import org.springframework.jdbc.datasource.lookup.JndiDataSourceLookup;
import org.springframework.jdbc.datasource.lookup.MapDataSourceLookup;
import org.springframework.util.ObjectUtils;

/**
 * Default implementation of the {@link PersistenceUnitManager} interface.
 * Used as internal default by
 * {@link org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean}.
 *
 * <p>Supports standard JPA scanning for persistence.xml files,
 * with configurable file locations, JDBC DataSource lookup and load-time weaving.
 *
 * <p>The default XML file location is classpath:META-INF/persistence.xml,
 * scanning for all matching files in the class path (as defined in the JPA specification).
 * DataSource names are by default interpreted as JNDI names, and no load time weaving
 * is available (which requires weaving to be turned off in the persistence provider).
 *
 * @author Juergen Hoeller
 * @since 2.0
 * @see #setPersistenceXmlLocations
 * @see #setDataSourceLookup
 * @see #setLoadTimeWeaver
 * @see org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean#setPersistenceUnitManager
 */
public class DefaultPersistenceUnitManager
		implements PersistenceUnitManager, ResourceLoaderAware, LoadTimeWeaverAware, InitializingBean {

	/**
	 * Default location of the <code>persistence.xml file:
	 * "classpath*:META-INF/persistence.xml".
	 */
	public final static String DEFAULT_PERSISTENCE_XML_LOCATION = "classpath*:META-INF/persistence.xml";

	/**
	 * Default location for the persistence unit root URL:
	 * "classpath:", indicating the root of the class path.
	 */
	public final static String ORIGINAL_DEFAULT_PERSISTENCE_UNIT_ROOT_LOCATION = "classpath:";


	/** Location of persistence.xml file(s) */
	private String[] persistenceXmlLocations = new String[] {DEFAULT_PERSISTENCE_XML_LOCATION};

	private String defaultPersistenceUnitRootLocation = ORIGINAL_DEFAULT_PERSISTENCE_UNIT_ROOT_LOCATION;

	private DataSourceLookup dataSourceLookup = new JndiDataSourceLookup();

	private DataSource defaultDataSource;

	private PersistenceUnitPostProcessor[] persistenceUnitPostProcessors;

	private LoadTimeWeaver loadTimeWeaver;

	private ResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();

	private final Set<String> persistenceUnitInfoNames = new HashSet();

	private final Map<String, MutablePersistenceUnitInfo> persistenceUnitInfos =
			new HashMap<String, MutablePersistenceUnitInfo>();


	/**
	 * Set the locations of the <code>persistence.xml files to load.
	 * These can be specified as Spring resource locations and/or location patterns.
	 * <p>Default is "classpath*:META-INF/persistence.xml".
	 * @param persistenceXmlLocations an array of Spring resource Strings
	 * identifying the location of the <code>persistence.xml files to read
	 */
	public void setPersistenceXmlLocations(String[] persistenceXmlLocations) {
		this.persistenceXmlLocations = persistenceXmlLocations;
	}

	/**
	 * Set the default persistence unit root location, to be applied
	 * if no unit-specific persistence unit root could be determined.
	 * <p>Default is "classpath:", that is, the root of the current class path
	 * (nearest root directory). To be overridden if unit-specific resolution
	 * does not work and the class path root is not appropriate either.
	 */
	public void setDefaultPersistenceUnitRootLocation(String defaultPersistenceUnitRootLocation) {
		this.defaultPersistenceUnitRootLocation = defaultPersistenceUnitRootLocation;
	}

	/**
	 * Specify the JDBC DataSources that the JPA persistence provider is supposed
	 * to use for accessing the database, resolving data source names in
	 * <code>persistence.xml against Spring-managed DataSources.
	 * <p>The specified Map needs to define data source names for specific DataSource
	 * objects, matching the data source names used in <code>persistence.xml.
	 * If not specified, data source names will be resolved as JNDI names instead
	 * (as defined by standard JPA).
	 * @see org.springframework.jdbc.datasource.lookup.MapDataSourceLookup
	 */
	public void setDataSources(Map<String, DataSource> dataSources) {
		this.dataSourceLookup = new MapDataSourceLookup(dataSources);
	}

	/**
	 * Specify the JDBC DataSourceLookup that provides DataSources for the
	 * persistence provider, resolving data source names in <code>persistence.xml
	 * against Spring-managed DataSource instances.
	 * <p>Default is JndiDataSourceLookup, which resolves DataSource names as
	 * JNDI names (as defined by standard JPA). Specify a BeanFactoryDataSourceLookup
	 * instance if you want DataSource names to be resolved against Spring bean names.
	 * <p>Alternatively, consider passing in a map from names to DataSource instances
	 * via the "dataSources" property. If the <code>persistence.xml file
	 * does not define DataSource names at all, specify a default DataSource
	 * via the "defaultDataSource" property.
	 * @see org.springframework.jdbc.datasource.lookup.JndiDataSourceLookup
	 * @see org.springframework.jdbc.datasource.lookup.BeanFactoryDataSourceLookup
	 * @see #setDataSources
	 * @see #setDefaultDataSource
	 */
	public void setDataSourceLookup(DataSourceLookup dataSourceLookup) {
		this.dataSourceLookup = (dataSourceLookup != null ? dataSourceLookup : new JndiDataSourceLookup());
	}

	/**
	 * Return the JDBC DataSourceLookup that provides DataSources for the
	 * persistence provider, resolving data source names in <code>persistence.xml
	 * against Spring-managed DataSource instances.
	 */
	public DataSourceLookup getDataSourceLookup() {
		return this.dataSourceLookup;
	}

	/**
	 * Specify the JDBC DataSource that the JPA persistence provider is supposed
	 * to use for accessing the database if none has been specified in
	 * <code>persistence.xml.
	 * <p>In JPA speak, a DataSource passed in here will be uses as "nonJtaDataSource"
	 * on the PersistenceUnitInfo passed to the PersistenceProvider, provided that
	 * none has been registered before.
	 * @see javax.persistence.spi.PersistenceUnitInfo#getNonJtaDataSource()
	 */
	public void setDefaultDataSource(DataSource defaultDataSource) {
		this.defaultDataSource = defaultDataSource;
	}

	/**
	 * Return the JDBC DataSource that the JPA persistence provider is supposed
	 * to use for accessing the database if none has been specified in
	 * <code>persistence.xml.
	 */
	public DataSource getDefaultDataSource() {
		return this.defaultDataSource;
	}

	/**
	 * Set the PersistenceUnitPostProcessors to be applied to each
	 * PersistenceUnitInfo that has been parsed by this manager.
	 * <p>Such post-processors can, for example, register further entity
	 * classes and jar files, in addition to the metadata read in from
	 * <code>persistence.xml.
	 */
	public void setPersistenceUnitPostProcessors(PersistenceUnitPostProcessor[] postProcessors) {
		this.persistenceUnitPostProcessors = postProcessors;
	}

	/**
	 * Return the PersistenceUnitPostProcessors to be applied to each
	 * PersistenceUnitInfo that has been parsed by this manager.
	 */
	public PersistenceUnitPostProcessor[] getPersistenceUnitPostProcessors() {
		return this.persistenceUnitPostProcessors;
	}

	/**
	 * Specify the Spring LoadTimeWeaver to use for class instrumentation according
	 * to the JPA class transformer contract.
	 * <p>It is not required to specify a LoadTimeWeaver: Most providers will be
	 * able to provide a subset of their functionality without class instrumentation
	 * as well, or operate with their VM agent specified on JVM startup.
	 * <p>In terms of Spring-provided weaving options, the most important ones are
	 * InstrumentationLoadTimeWeaver, which requires a Spring-specific (but very general)
	 * VM agent specified on JVM startup, and ReflectiveLoadTimeWeaver, which interacts
	 * with an underlying ClassLoader based on specific extended methods being available
	 * on it (for example, interacting with Spring's TomcatInstrumentableClassLoader).
	 * <p>NOTE: As of Spring 2.5, the context's default LoadTimeWeaver (defined
	 * as bean with name "loadTimeWeaver") will be picked up automatically, if available,
	 * removing the need for LoadTimeWeaver configuration on each affected target bean.</b>
	 * Consider using the <code>context:load-time-weaver XML tag for creating
	 * such a shared LoadTimeWeaver (autodetecting the environment by default).
	 * @see org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver
	 * @see org.springframework.instrument.classloading.ReflectiveLoadTimeWeaver
	 * @see org.springframework.instrument.classloading.tomcat.TomcatInstrumentableClassLoader
	 */
	public void setLoadTimeWeaver(LoadTimeWeaver loadTimeWeaver) {
		this.loadTimeWeaver = loadTimeWeaver;
	}

	/**
	 * Return the Spring LoadTimeWeaver to use for class instrumentation according
	 * to the JPA class transformer contract.
	 */
	public LoadTimeWeaver getLoadTimeWeaver() {
		return this.loadTimeWeaver;
	}

	public void setResourceLoader(ResourceLoader resourceLoader) {
		this.resourcePatternResolver = (resourceLoader != null ?
				ResourcePatternUtils.getResourcePatternResolver(resourceLoader) :
				new PathMatchingResourcePatternResolver());
	}


	public void afterPropertiesSet() {
		if (this.loadTimeWeaver == null && InstrumentationLoadTimeWeaver.isInstrumentationAvailable()) {
			this.loadTimeWeaver = new InstrumentationLoadTimeWeaver(this.resourcePatternResolver.getClassLoader());
		}
		preparePersistenceUnitInfos();
	}

	/**
	 * Prepare the PersistenceUnitInfos according to the configuration
	 * of this manager: scanning for <code>persistence.xml files,
	 * parsing all matching files, configurating and post-processing them.
	 * <p>PersistenceUnitInfos cannot be obtained before this preparation
	 * method has been invoked.
	 * @see #obtainDefaultPersistenceUnitInfo()
	 * @see #obtainPersistenceUnitInfo(String)
	 */
	public void preparePersistenceUnitInfos() {
		this.persistenceUnitInfoNames.clear();
		this.persistenceUnitInfos.clear();
		SpringPersistenceUnitInfo[] puis = readPersistenceUnitInfos();
		for (int i = 0; i < puis.length; i++) {
			SpringPersistenceUnitInfo pui = puis[i];
			if (pui.getPersistenceUnitRootUrl() == null) {
				pui.setPersistenceUnitRootUrl(determineDefaultPersistenceUnitRootUrl());
			}
			if (pui.getNonJtaDataSource() == null) {
				pui.setNonJtaDataSource(this.defaultDataSource);
			}
			if (this.loadTimeWeaver != null) {
				pui.init(this.loadTimeWeaver);
			}
			else {
				pui.init(this.resourcePatternResolver.getClassLoader());
			}
			postProcessPersistenceUnitInfo(pui);
			String name = pui.getPersistenceUnitName();
			this.persistenceUnitInfoNames.add(name);
			this.persistenceUnitInfos.put(name, pui);
		}
	}

	/**
	 * Read all persistence unit infos from <code>persistence.xml,
	 * as defined in the JPA specification.
	 */
	private SpringPersistenceUnitInfo[] readPersistenceUnitInfos() {
		PersistenceUnitReader reader = new PersistenceUnitReader(this.resourcePatternResolver, this.dataSourceLookup);
		return reader.readPersistenceUnitInfos(this.persistenceXmlLocations);
	}

	/**
	 * Try to determine the persistence unit root URL based on the given
	 * "defaultPersistenceUnitRootLocation".
	 * @return the persistence unit root URL to pass to the JPA PersistenceProvider
	 * @see #setDefaultPersistenceUnitRootLocation
	 */
	private URL determineDefaultPersistenceUnitRootUrl() {
		if (this.defaultPersistenceUnitRootLocation == null) {
			return null;
		}
		try {
			Resource res = this.resourcePatternResolver.getResource(this.defaultPersistenceUnitRootLocation);
			return res.getURL();
		}
		catch (IOException ex) {
			throw new PersistenceException("Unable to resolve persistence unit root URL", ex);
		}
	}

	/**
	 * Return the specified PersistenceUnitInfo from this manager's cache
	 * of processed persistence units, keeping it in the cache (i.e. not
	 * 'obtaining' it for use but rather just accessing it for post-processing).
	 * <p>This can be used in {@link #postProcessPersistenceUnitInfo} implementations,
	 * detecting existing persistence units of the same name and potentially merging them.
	 * @param persistenceUnitName the name of the desired persistence unit
	 * @return the PersistenceUnitInfo in mutable form,
	 * or <code>null if not available
	 */
	protected final MutablePersistenceUnitInfo getPersistenceUnitInfo(String persistenceUnitName) {
		return this.persistenceUnitInfos.get(persistenceUnitName);
	}

	/**
	 * Hook method allowing subclasses to customize each PersistenceUnitInfo.
	 * <p>Default implementation delegates to all registered PersistenceUnitPostProcessors.
	 * It is usually preferable to register further entity classes, jar files etc there
	 * rather than in a subclass of this manager, to be able to reuse the post-processors.
	 * @param pui the chosen PersistenceUnitInfo, as read from <code>persistence.xml.
	 * Passed in as MutablePersistenceUnitInfo.
	 * @see #setPersistenceUnitPostProcessors
	 */
	protected void postProcessPersistenceUnitInfo(MutablePersistenceUnitInfo pui) {
		PersistenceUnitPostProcessor[] postProcessors = getPersistenceUnitPostProcessors();
		if (postProcessors != null) {
			for (int i = 0; i < postProcessors.length; i++) {
				postProcessors[i].postProcessPersistenceUnitInfo(pui);
			}
		}
	}


	public PersistenceUnitInfo obtainDefaultPersistenceUnitInfo() {
		if (this.persistenceUnitInfoNames.isEmpty()) {
			throw new IllegalStateException("No persistence units parsed from " +
					ObjectUtils.nullSafeToString(this.persistenceXmlLocations));
		}
		if (this.persistenceUnitInfos.isEmpty()) {
			throw new IllegalStateException("All persistence units from " +
					ObjectUtils.nullSafeToString(this.persistenceXmlLocations) + " already obtained");
		}
		if (this.persistenceUnitInfos.size() > 1) {
			throw new IllegalStateException("No single default persistence unit defined in " +
					ObjectUtils.nullSafeToString(this.persistenceXmlLocations));
		}
		PersistenceUnitInfo pui = this.persistenceUnitInfos.values().iterator().next();
		this.persistenceUnitInfos.clear();
		return pui;
	}

	public PersistenceUnitInfo obtainPersistenceUnitInfo(String persistenceUnitName) {
		PersistenceUnitInfo pui = this.persistenceUnitInfos.remove(persistenceUnitName);
		if (pui == null) {
			if (!this.persistenceUnitInfoNames.contains(persistenceUnitName)) {
				throw new IllegalArgumentException(
						"No persistence unit with name '" + persistenceUnitName + "' found");
			}
			else {
				throw new IllegalStateException(
						"Persistence unit with name '" + persistenceUnitName + "' already obtained");
			}
		}
		return pui;
	}

}