JpaTransactionManager etc can find EntityManagerFactory by...

JpaTransactionManager etc can find EntityManagerFactory by "persistenceUnitName" property now, falling back to retrieval of a unique EntityManagerFactory bean by type (analogous to @PersistenceUnit / @PersistenceContext)

org.springframework.orm/src/main/java/org/springframework/orm/jpa/EntityManagerFactoryAccessor.java

 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2011 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.
@@ -19,13 +19,16 @@ package org.springframework.orm.jpa;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Properties;
-
 import javax.persistence.EntityManager;
 import javax.persistence.EntityManagerFactory;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.BeanFactoryAware;
+import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
 
@@ -40,13 +43,15 @@ import org.springframework.util.CollectionUtils;
  * @see JpaAccessor
  * @see EntityManagerFactoryUtils
  */
-public abstract class EntityManagerFactoryAccessor {
+public abstract class EntityManagerFactoryAccessor implements BeanFactoryAware {
 
 	/** Logger available to subclasses */
 	protected final Log logger = LogFactory.getLog(getClass());
 
 	private EntityManagerFactory entityManagerFactory;
 
+	private String persistenceUnitName;
+
 	private final Map<String, Object> jpaPropertyMap = new HashMap<String, Object>();
 
 
@@ -68,6 +73,25 @@ public abstract class EntityManagerFactoryAccessor {
 		return this.entityManagerFactory;
 	}
 
+	/**
+	 * Set the name of the persistence unit to access the EntityManagerFactory for.
+	 * <p>This is an alternative to specifying the EntityManagerFactory by direct reference,
+	 * resolving it by its persistence unit name instead. If no EntityManagerFactory and
+	 * no persistence unit name have been specified, a default EntityManagerFactory will
+	 * be retrieved through finding a single unique bean of type EntityManagerFactory.
+	 * @see #setEntityManagerFactory
+	 */
+	public void setPersistenceUnitName(String persistenceUnitName) {
+		this.persistenceUnitName = persistenceUnitName;
+	}
+
+	/**
+	 * Return the name of the persistence unit to access the EntityManagerFactory for, if any.
+	 */
+	public String getPersistenceUnitName() {
+		return this.persistenceUnitName;
+	}
+
 	/**
 	 * Specify JPA properties, to be passed into
 	 * <code>EntityManagerFactory.createEntityManager(Map)</code> (if any).
@@ -100,6 +124,22 @@ public abstract class EntityManagerFactoryAccessor {
 		return this.jpaPropertyMap;
 	}
 
+	/**
+	 * Retrieves an EntityManagerFactory by persistence unit name, if none set explicitly.
+	 * Falls back to a default EntityManagerFactory bean if no persistence unit specified.
+	 * @see #setPersistenceUnitName
+	 */
+	public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
+		if (getEntityManagerFactory() == null) {
+			if (!(beanFactory instanceof ListableBeanFactory)) {
+				throw new IllegalStateException("Cannot retrieve EntityManagerFactory by persistence unit name " +
+						"in a non-listable BeanFactory: " + beanFactory);
+			}
+			ListableBeanFactory lbf = (ListableBeanFactory) beanFactory;
+			setEntityManagerFactory(EntityManagerFactoryUtils.findEntityManagerFactory(lbf, getPersistenceUnitName()));
+		}
+	}
+
 
 	/**
 	 * Obtain a new EntityManager from this accessor's EntityManagerFactory.

org.springframework.orm/src/main/java/org/springframework/orm/jpa/EntityManagerFactoryUtils.java

 /*
- * Copyright 2002-2010 the original author or authors.
+ * Copyright 2002-2011 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.
@@ -46,6 +46,7 @@ import org.springframework.transaction.support.ResourceHolderSynchronization;
 import org.springframework.transaction.support.TransactionSynchronizationManager;
 import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
+import org.springframework.util.StringUtils;
 
 /**
  * Helper class featuring methods for JPA EntityManager handling,
@@ -80,7 +81,8 @@ public abstract class EntityManagerFactoryUtils {
 	 * the persistence unit name will be matched against the Spring bean name,
 	 * assuming that the EntityManagerFactory bean names follow that convention.
 	 * @param beanFactory the ListableBeanFactory to search
-	 * @param unitName the name of the persistence unit (never empty)
+	 * @param unitName the name of the persistence unit (may be <code>null</code> or empty,
+	 * in which case a single bean of type EntityManagerFactory will be searched for)
 	 * @return the EntityManagerFactory
 	 * @throws NoSuchBeanDefinitionException if there is no such EntityManagerFactory in the context
 	 * @see EntityManagerFactoryInfo#getPersistenceUnitName()
@@ -89,22 +91,25 @@ public abstract class EntityManagerFactoryUtils {
 			ListableBeanFactory beanFactory, String unitName) throws NoSuchBeanDefinitionException {
 
 		Assert.notNull(beanFactory, "ListableBeanFactory must not be null");
-		Assert.hasLength(unitName, "Unit name must not be empty");
-
-		// See whether we can find an EntityManagerFactory with matching persistence unit name.
-		String[] candidateNames =
-				BeanFactoryUtils.beanNamesForTypeIncludingAncestors(beanFactory, EntityManagerFactory.class);
-		for (String candidateName : candidateNames) {
-			EntityManagerFactory emf = (EntityManagerFactory) beanFactory.getBean(candidateName);
-			if (emf instanceof EntityManagerFactoryInfo) {
-				if (unitName.equals(((EntityManagerFactoryInfo) emf).getPersistenceUnitName())) {
-					return emf;
+		if (StringUtils.hasLength(unitName)) {
+			// See whether we can find an EntityManagerFactory with matching persistence unit name.
+			String[] candidateNames =
+					BeanFactoryUtils.beanNamesForTypeIncludingAncestors(beanFactory, EntityManagerFactory.class);
+			for (String candidateName : candidateNames) {
+				EntityManagerFactory emf = (EntityManagerFactory) beanFactory.getBean(candidateName);
+				if (emf instanceof EntityManagerFactoryInfo) {
+					if (unitName.equals(((EntityManagerFactoryInfo) emf).getPersistenceUnitName())) {
+						return emf;
+					}
 				}
 			}
+			// No matching persistence unit found - simply take the EntityManagerFactory
+			// with the persistence unit name as bean name (by convention).
+			return beanFactory.getBean(unitName, EntityManagerFactory.class);
+		}
+		else {
+			return BeanFactoryUtils.beanOfType(beanFactory, EntityManagerFactory.class);
 		}
-		// No matching persistence unit found - simply take the EntityManagerFactory
-		// with the persistence unit name as bean name (by convention).
-		return beanFactory.getBean(unitName, EntityManagerFactory.class);
 	}
 
 	/**

org.springframework.orm/src/main/java/org/springframework/orm/jpa/JpaTransactionManager.java

@@ -26,7 +26,11 @@ import javax.persistence.PersistenceException;
 import javax.persistence.RollbackException;
 import javax.sql.DataSource;
 
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.BeanFactoryAware;
 import org.springframework.beans.factory.InitializingBean;
+import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.dao.DataAccessException;
 import org.springframework.dao.support.DataAccessUtils;
 import org.springframework.jdbc.datasource.ConnectionHandle;
@@ -105,10 +109,12 @@ import org.springframework.util.CollectionUtils;
  * @see org.springframework.transaction.jta.JtaTransactionManager
  */
 public class JpaTransactionManager extends AbstractPlatformTransactionManager
-		implements ResourceTransactionManager, InitializingBean {
+		implements ResourceTransactionManager, BeanFactoryAware, InitializingBean {
 
 	private EntityManagerFactory entityManagerFactory;
 
+	private String persistenceUnitName;
+
 	private final Map<String, Object> jpaPropertyMap = new HashMap<String, Object>();
 
 	private DataSource dataSource;
@@ -138,6 +144,10 @@ public class JpaTransactionManager extends AbstractPlatformTransactionManager
 
 	/**
 	 * Set the EntityManagerFactory that this instance should manage transactions for.
+	 * <p>Alternatively, specify the persistence unit name of the target EntityManagerFactory.
+	 * By default, a default EntityManagerFactory will be retrieved through finding a
+	 * single unique bean of type EntityManagerFactory in the containing BeanFactory.
+	 * @see #setPersistenceUnitName
 	 */
 	public void setEntityManagerFactory(EntityManagerFactory emf) {
 		this.entityManagerFactory = emf;
@@ -150,6 +160,25 @@ public class JpaTransactionManager extends AbstractPlatformTransactionManager
 		return this.entityManagerFactory;
 	}
 
+	/**
+	 * Set the name of the persistence unit to manage transactions for.
+	 * <p>This is an alternative to specifying the EntityManagerFactory by direct reference,
+	 * resolving it by its persistence unit name instead. If no EntityManagerFactory and
+	 * no persistence unit name have been specified, a default EntityManagerFactory will
+	 * be retrieved through finding a single unique bean of type EntityManagerFactory.
+	 * @see #setEntityManagerFactory
+	 */
+	public void setPersistenceUnitName(String persistenceUnitName) {
+		this.persistenceUnitName = persistenceUnitName;
+	}
+
+	/**
+	 * Return the name of the persistence unit to manage transactions for, if any.
+	 */
+	public String getPersistenceUnitName() {
+		return this.persistenceUnitName;
+	}
+
 	/**
 	 * Specify JPA properties, to be passed into
 	 * <code>EntityManagerFactory.createEntityManager(Map)</code> (if any).
@@ -247,6 +276,22 @@ public class JpaTransactionManager extends AbstractPlatformTransactionManager
 		return this.jpaDialect;
 	}
 
+	/**
+	 * Retrieves an EntityManagerFactory by persistence unit name, if none set explicitly.
+	 * Falls back to a default EntityManagerFactory bean if no persistence unit specified.
+	 * @see #setPersistenceUnitName
+	 */
+	public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
+		if (getEntityManagerFactory() == null) {
+			if (!(beanFactory instanceof ListableBeanFactory)) {
+				throw new IllegalStateException("Cannot retrieve EntityManagerFactory by persistence unit name " +
+						"in a non-listable BeanFactory: " + beanFactory);
+			}
+			ListableBeanFactory lbf = (ListableBeanFactory) beanFactory;
+			setEntityManagerFactory(EntityManagerFactoryUtils.findEntityManagerFactory(lbf, getPersistenceUnitName()));
+		}
+	}
+
 	/**
 	 * Eagerly initialize the JPA dialect, creating a default one
 	 * for the specified EntityManagerFactory if none set.
@@ -254,7 +299,7 @@ public class JpaTransactionManager extends AbstractPlatformTransactionManager
 	 */
 	public void afterPropertiesSet() {
 		if (getEntityManagerFactory() == null) {
-			throw new IllegalArgumentException("Property 'entityManagerFactory' is required");
+			throw new IllegalArgumentException("'entityManagerFactory' or 'persistenceUnitName' is required");
 		}
 		if (getEntityManagerFactory() instanceof EntityManagerFactoryInfo) {
 			EntityManagerFactoryInfo emfInfo = (EntityManagerFactoryInfo) getEntityManagerFactory();

org.springframework.orm/src/main/java/org/springframework/orm/jpa/support/OpenEntityManagerInViewFilter.java

 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2011 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.
@@ -17,7 +17,6 @@
 package org.springframework.orm.jpa.support;
 
 import java.io.IOException;
-
 import javax.persistence.EntityManager;
 import javax.persistence.EntityManagerFactory;
 import javax.persistence.PersistenceException;
@@ -27,9 +26,10 @@ import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
 import org.springframework.dao.DataAccessResourceFailureException;
-import org.springframework.orm.jpa.EntityManagerHolder;
 import org.springframework.orm.jpa.EntityManagerFactoryUtils;
+import org.springframework.orm.jpa.EntityManagerHolder;
 import org.springframework.transaction.support.TransactionSynchronizationManager;
+import org.springframework.util.StringUtils;
 import org.springframework.web.context.WebApplicationContext;
 import org.springframework.web.context.support.WebApplicationContextUtils;
 import org.springframework.web.filter.OncePerRequestFilter;
@@ -47,10 +47,10 @@ import org.springframework.web.filter.OncePerRequestFilter;
  * as for non-transactional read-only execution.
  *
  * <p>Looks up the EntityManagerFactory in Spring's root web application context.
- * Supports a "entityManagerFactoryBeanName" filter init-param in <code>web.xml</code>;
- * the default bean name is "entityManagerFactory". Looks up the EntityManagerFactory
- * on each request, to avoid initialization order issues (when using ContextLoaderServlet,
- * the root application context will get initialized <i>after</i> this filter).
+ * Supports an "entityManagerFactoryBeanName" filter init-param in <code>web.xml</code>;
+ * the default bean name is "entityManagerFactory". As an alternative, the
+ * "persistenceUnitName" init-param allows for retrieval by logical unit name
+ * (as specified in <code>persistence.xml</code>).
  *
  * @author Juergen Hoeller
  * @since 2.0
@@ -63,15 +63,28 @@ import org.springframework.web.filter.OncePerRequestFilter;
  */
 public class OpenEntityManagerInViewFilter extends OncePerRequestFilter {
 
-	public static final String DEFAULT_PERSISTENCE_MANAGER_FACTORY_BEAN_NAME = "entityManagerFactory";
+	/**
+	 * Default EntityManagerFactory bean name: "entityManagerFactory".
+	 * Only applies when no "persistenceUnitName" param has been specified.
+	 * @see #setEntityManagerFactoryBeanName
+	 * @see #setPersistenceUnitName
+	 */
+	public static final String DEFAULT_ENTITY_MANAGER_FACTORY_BEAN_NAME = "entityManagerFactory";
+
+	private String entityManagerFactoryBeanName;
 
-	private String entityManagerFactoryBeanName = DEFAULT_PERSISTENCE_MANAGER_FACTORY_BEAN_NAME;
+	private String persistenceUnitName;
+
+	private volatile EntityManagerFactory entityManagerFactory;
 
 
 	/**
 	 * Set the bean name of the EntityManagerFactory to fetch from Spring's
-	 * root application context. Default is "entityManagerFactory".
-	 * @see #DEFAULT_PERSISTENCE_MANAGER_FACTORY_BEAN_NAME
+	 * root application context.
+	 * <p>Default is "entityManagerFactory". Note that this default only applies
+	 * when no "persistenceUnitName" param has been specified.
+	 * @see #setPersistenceUnitName
+	 * @see #DEFAULT_ENTITY_MANAGER_FACTORY_BEAN_NAME
 	 */
 	public void setEntityManagerFactoryBeanName(String entityManagerFactoryBeanName) {
 		this.entityManagerFactoryBeanName = entityManagerFactoryBeanName;
@@ -85,6 +98,27 @@ public class OpenEntityManagerInViewFilter extends OncePerRequestFilter {
 		return this.entityManagerFactoryBeanName;
 	}
 
+	/**
+	 * Set the name of the persistence unit to access the EntityManagerFactory for.
+	 * <p>This is an alternative to specifying the EntityManagerFactory by bean name,
+	 * resolving it by its persistence unit name instead. If no bean name and no persistence
+	 * unit name have been specified, we'll check whether a bean exists for the default
+	 * bean name "entityManagerFactory"; if not, a default EntityManagerFactory will
+	 * be retrieved through finding a single unique bean of type EntityManagerFactory.
+	 * @see #setEntityManagerFactoryBeanName
+	 * @see #DEFAULT_ENTITY_MANAGER_FACTORY_BEAN_NAME
+	 */
+	public void setPersistenceUnitName(String persistenceUnitName) {
+		this.persistenceUnitName = persistenceUnitName;
+	}
+
+	/**
+	 * Return the name of the persistence unit to access the EntityManagerFactory for, if any.
+	 */
+	protected String getPersistenceUnitName() {
+		return this.persistenceUnitName;
+	}
+
 
 	@Override
 	protected void doFilterInternal(
@@ -126,29 +160,39 @@ public class OpenEntityManagerInViewFilter extends OncePerRequestFilter {
 	/**
 	 * Look up the EntityManagerFactory that this filter should use,
 	 * taking the current HTTP request as argument.
-	 * <p>Default implementation delegates to the <code>lookupEntityManagerFactory</code>
-	 * without arguments.
+	 * <p>The default implementation delegates to the <code>lookupEntityManagerFactory</code>
+	 * without arguments, caching the EntityManagerFactory reference once obtained.
 	 * @return the EntityManagerFactory to use
 	 * @see #lookupEntityManagerFactory()
 	 */
 	protected EntityManagerFactory lookupEntityManagerFactory(HttpServletRequest request) {
-		return lookupEntityManagerFactory();
+		if (this.entityManagerFactory == null) {
+			this.entityManagerFactory = lookupEntityManagerFactory();
+		}
+		return this.entityManagerFactory;
 	}
 
 	/**
 	 * Look up the EntityManagerFactory that this filter should use.
-	 * The default implementation looks for a bean with the specified name
+	 * <p>The default implementation looks for a bean with the specified name
 	 * in Spring's root application context.
 	 * @return the EntityManagerFactory to use
 	 * @see #getEntityManagerFactoryBeanName
 	 */
 	protected EntityManagerFactory lookupEntityManagerFactory() {
-		if (logger.isDebugEnabled()) {
-			logger.debug("Using EntityManagerFactory '" + getEntityManagerFactoryBeanName() +
-					"' for OpenEntityManagerInViewFilter");
-		}
 		WebApplicationContext wac = WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());
-		return wac.getBean(getEntityManagerFactoryBeanName(), EntityManagerFactory.class);
+		String emfBeanName = getEntityManagerFactoryBeanName();
+		String puName = getPersistenceUnitName();
+		if (StringUtils.hasLength(emfBeanName)) {
+			return wac.getBean(emfBeanName, EntityManagerFactory.class);
+		}
+		else if (!StringUtils.hasLength(puName) && wac.containsBean(DEFAULT_ENTITY_MANAGER_FACTORY_BEAN_NAME)) {
+			return wac.getBean(DEFAULT_ENTITY_MANAGER_FACTORY_BEAN_NAME, EntityManagerFactory.class);
+		}
+		else {
+			// Includes fallback search for single EntityManagerFactory bean by type.
+			return EntityManagerFactoryUtils.findEntityManagerFactory(wac, puName);
+		}
 	}
 
 	/**

org.springframework.orm/src/main/java/org/springframework/orm/jpa/support/SharedEntityManagerBean.java

 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2011 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.
@@ -67,7 +67,7 @@ public class SharedEntityManagerBean extends EntityManagerFactoryAccessor
 	 * @see javax.persistence.EntityManager
 	 */
 	public void setEntityManagerInterface(Class<? extends EntityManager> entityManagerInterface) {
-		Assert.notNull(entityManagerInterface, "entityManagerInterface must not be null");
+		Assert.notNull(entityManagerInterface, "'entityManagerInterface' must not be null");
 		Assert.isAssignable(EntityManager.class, entityManagerInterface);
 		this.entityManagerInterface = entityManagerInterface;
 	}
@@ -76,7 +76,7 @@ public class SharedEntityManagerBean extends EntityManagerFactoryAccessor
 	public final void afterPropertiesSet() {
 		EntityManagerFactory emf = getEntityManagerFactory();
 		if (emf == null) {
-			throw new IllegalArgumentException("entityManagerFactory is required");
+			throw new IllegalArgumentException("'entityManagerFactory' or 'persistenceUnitName' is required");
 		}
 		Class[] ifcs = null;
 		if (emf instanceof EntityManagerFactoryInfo) {