| /** |
| * 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.apache.tapestry5.internal.jpa; |
| |
| import java.util.ArrayDeque; |
| import java.util.ArrayList; |
| import java.util.Deque; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import javax.persistence.EntityManager; |
| import javax.persistence.EntityTransaction; |
| |
| import org.apache.tapestry5.ioc.Invokable; |
| import org.apache.tapestry5.jpa.EntityTransactionManager.VoidInvokable; |
| import org.slf4j.Logger; |
| |
| public class PersistenceContextSpecificEntityTransactionManager |
| { |
| |
| private final Logger logger; |
| private final EntityManager entityManager; |
| |
| private boolean transactionBeingCommitted; |
| |
| private Deque<Invokable<?>> invokableUnitsForSequentialTransactions = new ArrayDeque<Invokable<?>>(); |
| private Deque<Invokable<?>> invokableUnits = new ArrayDeque<Invokable<?>>(); |
| |
| private List<Invokable<Boolean>> beforeCommitInvokables = new ArrayList<Invokable<Boolean>>(); |
| private List<Invokable<Boolean>> afterCommitInvokables = new ArrayList<Invokable<Boolean>>(); |
| |
| public PersistenceContextSpecificEntityTransactionManager(Logger logger, |
| EntityManager entityManager) |
| { |
| this.logger = logger; |
| this.entityManager = entityManager; |
| } |
| |
| private EntityTransaction getTransaction() |
| { |
| EntityTransaction transaction = entityManager.getTransaction(); |
| if (!transaction.isActive()) |
| transaction.begin(); |
| return transaction; |
| } |
| |
| public void addBeforeCommitInvokable(Invokable<Boolean> invokable) |
| { |
| beforeCommitInvokables.add(invokable); |
| } |
| |
| public void addAfterCommitInvokable(Invokable<Boolean> invokable) |
| { |
| afterCommitInvokables.add(invokable); |
| } |
| |
| public <T> T invokeInTransaction(Invokable<T> invokable) |
| { |
| final EntityTransaction transaction = getTransaction(); |
| if (transactionBeingCommitted) |
| { |
| // happens for example if you try to run a transaction in @PostCommit hook. We can only |
| // allow VoidInvokables |
| // to be executed later |
| if (invokable instanceof VoidInvokable) |
| { |
| invokableUnitsForSequentialTransactions.push(invokable); |
| return null; |
| } |
| else |
| { |
| rollbackTransaction(transaction); |
| throw new RuntimeException( |
| "Current transaction is already being committed. Transactions started @PostCommit are not allowed to return a value"); |
| } |
| } |
| |
| final boolean topLevel = invokableUnits.isEmpty(); |
| invokableUnits.push(invokable); |
| if (!topLevel) |
| { |
| if (logger.isWarnEnabled()) |
| { |
| logger.warn("Nested transaction detected, current depth = " + invokableUnits.size()); |
| } |
| } |
| |
| try |
| { |
| T result = invokable.invoke(); |
| |
| if (topLevel && invokableUnits.peek().equals(invokable)) |
| { |
| // Success or checked exception: |
| |
| boolean isActive = transaction.isActive(); |
| if (isActive) |
| { |
| invokeBeforeCommit(transaction); |
| // FIXME check if we are still on top |
| transactionBeingCommitted = true; |
| transaction.commit(); |
| transactionBeingCommitted = false; |
| invokableUnits.clear(); |
| invokeAfterCommit(); |
| if (invokableUnitsForSequentialTransactions.size() > 0) |
| invokeInTransaction(invokableUnitsForSequentialTransactions.pop()); |
| } |
| } |
| |
| return result; |
| } |
| catch (final RuntimeException e) |
| { |
| if (transaction != null && transaction.isActive()) |
| { |
| rollbackTransaction(transaction); |
| } |
| |
| throw e; |
| } |
| finally |
| { |
| invokableUnits.remove(invokable); |
| } |
| } |
| |
| private void invokeBeforeCommit(final EntityTransaction transaction) |
| { |
| for (Iterator<Invokable<Boolean>> i = beforeCommitInvokables.iterator(); i.hasNext();) |
| { |
| Invokable<Boolean> invokable = i.next(); |
| i.remove(); |
| Boolean beforeCommitSucceeded = tryInvoke(transaction, invokable); |
| |
| // Success or checked exception: |
| if (beforeCommitSucceeded != null && !beforeCommitSucceeded.booleanValue()) |
| { |
| rollbackTransaction(transaction); |
| |
| // Don't invoke further callbacks |
| break; |
| } |
| } |
| } |
| |
| private void invokeAfterCommit() |
| { |
| |
| for (Iterator<Invokable<Boolean>> i = afterCommitInvokables.iterator(); i.hasNext();) |
| { |
| Invokable<Boolean> invokable = i.next(); |
| i.remove(); |
| Boolean afterCommitSucceeded = invokable.invoke(); |
| |
| // Success or checked exception: |
| if (afterCommitSucceeded != null && !afterCommitSucceeded.booleanValue()) |
| { |
| if (invokableUnitsForSequentialTransactions.size() > 0) { throw new RuntimeException( |
| "After commit hook returned false but there are still uncommitted Invokables scheduled for the next transaction"); } |
| return; |
| } |
| } |
| } |
| |
| private static <T> T tryInvoke(final EntityTransaction transaction, Invokable<T> invokable) |
| throws RuntimeException |
| { |
| T result; |
| |
| try |
| { |
| result = invokable.invoke(); |
| } |
| catch (final RuntimeException e) |
| { |
| if (transaction != null && transaction.isActive()) |
| { |
| rollbackTransaction(transaction); |
| } |
| |
| throw e; |
| } |
| |
| return result; |
| } |
| |
| private static void rollbackTransaction(EntityTransaction transaction) |
| { |
| try |
| { |
| transaction.rollback(); |
| } |
| catch (Exception e) |
| { // Ignore |
| } |
| } |
| } |