| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.aries.jpa.cdi; |
| |
| import javax.enterprise.context.ContextNotActiveException; |
| import javax.enterprise.context.spi.Context; |
| import javax.enterprise.context.spi.Contextual; |
| import javax.enterprise.context.spi.CreationalContext; |
| import javax.enterprise.inject.spi.Bean; |
| import javax.enterprise.inject.spi.BeanManager; |
| import javax.transaction.Status; |
| import javax.transaction.Synchronization; |
| import javax.transaction.SystemException; |
| import javax.transaction.TransactionScoped; |
| import java.lang.annotation.Annotation; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| public class TransactionalContext implements Context { |
| |
| private static final Object TRANSACTION_BEANS_KEY = TransactionalContext.class.getName() + ".TRANSACTION_BEANS"; |
| |
| private static final Logger log = LoggerFactory.getLogger(TransactionalContext.class); |
| |
| private BeanManager beanManager; |
| |
| private volatile TransactionSupport transactionSupport; |
| |
| /** |
| * Creates a new transactional context. |
| * |
| * @param beanManager {@link BeanManager}. |
| */ |
| TransactionalContext(BeanManager beanManager) { |
| this.beanManager = beanManager; |
| } |
| |
| /** |
| * Obtains a reference to a {@link TransactionSupport} bean. |
| * |
| * @return a bean that implements {@link TransactionSupport}. |
| */ |
| private TransactionSupport getTransactionSupportReference() { |
| @SuppressWarnings("unchecked") |
| Bean<TransactionSupport> bean = (Bean<TransactionSupport>) beanManager |
| .resolve(beanManager.getBeans(TransactionSupport.class)); |
| if (bean == null) { |
| throw new RuntimeException("TransactionSupport was not found"); |
| } |
| |
| CreationalContext<TransactionSupport> ctx = beanManager.createCreationalContext(bean); |
| return (TransactionSupport) beanManager.getReference(bean, |
| TransactionSupport.class, ctx); |
| } |
| |
| /** |
| * Lazily initialize the object field and gets a reference to a bean that |
| * implements {@link TransactionSupport}. |
| * |
| * @return a bean that implements {@link TransactionSupport}. |
| */ |
| private TransactionSupport getTransactionSupport() { |
| if (transactionSupport == null) { |
| synchronized (this) { |
| if (transactionSupport == null) { |
| transactionSupport = getTransactionSupportReference(); |
| } |
| } |
| } |
| |
| return transactionSupport; |
| } |
| |
| /** |
| * Registers a synchronization object for the current transaction. |
| * |
| * @param transactionSupport a {@link TransactionSupport} bean. |
| * @param instances a map that contains transaction scoped beans for the |
| * current transaction. |
| */ |
| private <T> void registerSynchronization( |
| TransactionSupport transactionSupport, |
| Map<Contextual<T>, ContextualInstance<T>> instances) { |
| transactionSupport.getTransactionSynchronizationRegistry() |
| .registerInterposedSynchronization(new TransactionSynchronization<T>(instances)); |
| } |
| |
| /** |
| * Retrieves the map that contains transaction scoped beans for the current |
| * transaction. |
| * |
| * @param transactionSupport a bean that implements {@link TransactionSupport}. |
| * @return instances of transaction scoped beans for the current |
| * transaction. |
| */ |
| private <T> Map<Contextual<T>, ContextualInstance<T>> getInstances( |
| TransactionSupport transactionSupport) { |
| @SuppressWarnings("unchecked") |
| Map<Contextual<T>, ContextualInstance<T>> instances = |
| (Map<Contextual<T>, ContextualInstance<T>>) transactionSupport.getTransactionSynchronizationRegistry() |
| .getResource(TRANSACTION_BEANS_KEY); |
| if (instances == null) { |
| instances = new HashMap<Contextual<T>, ContextualInstance<T>>(); |
| transactionSupport |
| .getTransactionSynchronizationRegistry() |
| .putResource(TRANSACTION_BEANS_KEY, instances); |
| |
| registerSynchronization(transactionSupport, instances); |
| } |
| |
| return instances; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public <T> T get( |
| Contextual<T> contextual) { |
| return get(contextual, null); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public <T> T get( |
| Contextual<T> contextual, |
| CreationalContext<T> creationalContext) { |
| if (!isActive()) { |
| throw new ContextNotActiveException(); |
| } |
| |
| if (contextual == null) { |
| throw new IllegalArgumentException( |
| "No contextual specified to retrieve"); |
| } |
| |
| TransactionSupport transactionSupport = getTransactionSupport(); |
| Map<Contextual<T>, ContextualInstance<T>> instances = |
| getInstances(transactionSupport); |
| ContextualInstance<T> contextualInstance = instances.get(contextual); |
| if (contextualInstance != null) { |
| return contextualInstance.instance; |
| } else if (creationalContext == null) { |
| return null; |
| } else { |
| T instance = contextual.create(creationalContext); |
| contextualInstance = new ContextualInstance<T>(instance, |
| creationalContext); |
| instances.put(contextual, contextualInstance); |
| |
| if (log.isDebugEnabled()) { |
| log.debug("Created a new transaction scoped instance " |
| + contextualInstance); |
| } |
| |
| return instance; |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public Class<? extends Annotation> getScope() { |
| return TransactionScoped.class; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public boolean isActive() { |
| try { |
| return getTransactionSupport().getTransactionManager().getStatus() == Status.STATUS_ACTIVE; |
| } catch (SystemException e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| /** |
| * <p> |
| * Synchronization object that destroys transaction scoped beans after the |
| * transaction ends. |
| * </p> |
| * |
| * @author Vlad Arkhipov |
| */ |
| private static class TransactionSynchronization<T> |
| implements Synchronization { |
| private Map<Contextual<T>, ContextualInstance<T>> instances; |
| |
| /** |
| * Creates a new synchronization. |
| * |
| * @param instances instances of transaction scoped beans for the |
| * current transaction. |
| */ |
| TransactionSynchronization( |
| Map<Contextual<T>, ContextualInstance<T>> instances) { |
| this.instances = instances; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void beforeCompletion() { |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void afterCompletion( |
| int status) { |
| for (Map.Entry<Contextual<T>, ContextualInstance<T>> entry : instances.entrySet()) { |
| entry.getValue().destroy(entry.getKey()); |
| } |
| } |
| } |
| |
| /** |
| * <p> |
| * An object that represents an instance of a bean. Contains a reference for |
| * a bean and {@link CreationalContext}. |
| * </p> |
| * |
| * @author Vlad Arkhipov |
| */ |
| private static class ContextualInstance<T> { |
| private T instance; |
| |
| private CreationalContext<T> creationalContext; |
| |
| /** |
| * Creates a new object that represents an instance of a bean. |
| * |
| * @param instance an instance of a bean. |
| * @param creationalContext a {@link CreationalContext}. |
| */ |
| public ContextualInstance( |
| T instance, |
| CreationalContext<T> creationalContext) { |
| this.instance = instance; |
| this.creationalContext = creationalContext; |
| } |
| |
| /** |
| * Destroys the bean. |
| * |
| * @param contextual a {@link Contextual}. |
| */ |
| void destroy( |
| Contextual<T> contextual) { |
| if (log.isDebugEnabled()) { |
| log.debug("Destroying transaction scoped bean instance " |
| + this); |
| } |
| |
| contextual.destroy(instance, creationalContext); |
| creationalContext.release(); |
| } |
| } |
| } |