/*
* Copyright 2015 Red Hat, Inc. and/or its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
*
* 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.jbpm.process.audit.strategy;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.transaction.Status;
import javax.transaction.UserTransaction;
import org.jbpm.process.audit.JPAWorkingMemoryDbLogger;
import org.kie.api.runtime.KieSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* This strategy is used by instances that are<ul>
* <li>used outside the {@link KieSession}</li>
* <li>use their own {@link EntityManager} instance per operation</li>
* </ul>
*/
public class StandaloneJtaStrategy implements PersistenceStrategy {
private static final Logger logger = LoggerFactory.getLogger(JPAWorkingMemoryDbLogger.class);
private static final String[] KNOWN_UT_JNDI_KEYS = new String[] {"UserTransaction", "java:jboss/UserTransaction", System.getProperty("jbpm.ut.jndi.lookup")};
protected EntityManagerFactory emf;
private static final Object USER_MANAGED_TRANSACTION = new Object();
public StandaloneJtaStrategy(EntityManagerFactory emf) {
this.emf = emf;
}
@Override
public EntityManager getEntityManager() {
return emf.createEntityManager();
}
@Override
public Object joinTransaction(EntityManager em) {
boolean newTx = false;
UserTransaction ut = findUserTransaction();
if( ut == null ) {
throw new IllegalStateException("Unable to find JTA transaction." );
}
try {
if( ut.getStatus() == Status.STATUS_NO_TRANSACTION ) {
ut.begin();
newTx = true;
// since new transaction was started em must join it
}
} catch(Exception ex) {
throw new IllegalStateException("Unable to find or open a transaction: " + ex.getMessage(), ex);
}
try {
em.joinTransaction();
} catch( Exception e) {
throw new IllegalStateException("Unable to join EntityManager to transaction: " + e.getMessage(), e);
}
if( newTx ) {
return ut;
}
return USER_MANAGED_TRANSACTION;
}
protected static UserTransaction findUserTransaction() {
InitialContext context = null;
try {
context = new InitialContext();
} catch( Exception e ) {
throw new IllegalStateException("Unable to initialized " + InitialContext.class.getName() + " instance.", e);
}
try {
return (UserTransaction) context.lookup( "java:comp/UserTransaction" );
} catch ( NamingException ex ) {
for (String utLookup : KNOWN_UT_JNDI_KEYS) {
if (utLookup != null) {
try {
UserTransaction ut = (UserTransaction) context.lookup(utLookup);
return ut;
} catch (NamingException e) {
logger.debug("User Transaction not found in JNDI under {}", utLookup);
}
}
}
logger.warn("No user transaction found under known names");
return null;
}
}
@Override
public void leaveTransaction(EntityManager em, Object transaction) {
commitTransaction(transaction);
em.clear();
em.close();
}
protected void commitTransaction(Object transaction) {
if( transaction == USER_MANAGED_TRANSACTION ) {
return;
}
UserTransaction ut = null;
if( ! (transaction instanceof UserTransaction) ) {
throw new IllegalStateException("This persistence strategy only deals with UserTransaction instances!" );
} else if( transaction != null ){
ut = (UserTransaction) transaction;
}
try {
if( ut != null ) {
// There's a tx running, close it.
ut.commit();
}
} catch(Exception e) {
logger.error("Unable to commit transaction: ", e);
}
}
@Override
public void dispose() {
// NEVER close the emf, you don't know what it is also being used for!
emf = null;
}
}