package org.drools.persistence.jpa;
import java.lang.reflect.Field;
import javax.persistence.EntityManager;
import javax.persistence.LockModeType;
import org.drools.persistence.PersistenceContext;
import org.drools.persistence.TransactionManager;
import org.drools.persistence.TransactionManagerHelper;
import org.drools.persistence.info.SessionInfo;
import org.drools.persistence.info.WorkItemInfo;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class JpaPersistenceContext implements PersistenceContext {
private static Logger logger = LoggerFactory.getLogger(JpaPersistenceContext.class);
private EntityManager em;
protected final boolean isJTA;
protected final boolean pessimisticLocking;
protected final TransactionManager txm;
public JpaPersistenceContext(EntityManager em, TransactionManager txm) {
this(em, true, false, txm);
}
public JpaPersistenceContext(EntityManager em, boolean isJTA, TransactionManager txm) {
this(em, isJTA, false, txm);
}
public JpaPersistenceContext(EntityManager em, boolean isJTA, boolean locking, TransactionManager txm) {
this.em = em;
this.isJTA = isJTA;
this.pessimisticLocking = locking;
this.txm = txm;
}
public SessionInfo persist(SessionInfo entity) {
this.em.persist( entity );
TransactionManagerHelper.addToUpdatableSet(txm, entity);
if( this.pessimisticLocking ) {
return this.em.find(SessionInfo.class, entity.getId(), LockModeType.PESSIMISTIC_FORCE_INCREMENT );
}
return entity;
}
public SessionInfo findSessionInfo(Integer id) {
SessionInfo sessionInfo = null;
if( this.pessimisticLocking ) {
sessionInfo = this.em.find( SessionInfo.class, id, LockModeType.PESSIMISTIC_FORCE_INCREMENT );
TransactionManagerHelper.addToUpdatableSet(txm, sessionInfo);
return sessionInfo;
}
sessionInfo = this.em.find( SessionInfo.class, id );
TransactionManagerHelper.addToUpdatableSet(txm, sessionInfo);
return sessionInfo;
}
public void remove(SessionInfo sessionInfo) {
if (!em.contains(sessionInfo)) {
SessionInfo s = em.getReference(SessionInfo.class, sessionInfo.getId());
em.remove( s );
} else {
em.remove(sessionInfo);
}
TransactionManagerHelper.removeFromUpdatableSet(txm, sessionInfo);
em.flush();
}
public void lock(SessionInfo sessionInfo) {
this.em.lock( sessionInfo, LockModeType.PESSIMISTIC_FORCE_INCREMENT );
}
public boolean isOpen() {
return this.em.isOpen();
}
public void joinTransaction() {
if (isJTA) {
this.em.joinTransaction();
}
}
public void close() {
this.em.close();
}
public WorkItemInfo persist(WorkItemInfo workItemInfo) {
em.persist( workItemInfo );
TransactionManagerHelper.addToUpdatableSet(txm, workItemInfo);
if( this.pessimisticLocking ) {
return em.find(WorkItemInfo.class, workItemInfo.getId(), LockModeType.PESSIMISTIC_FORCE_INCREMENT);
}
return workItemInfo;
}
public WorkItemInfo findWorkItemInfo(Long id) {
WorkItemInfo workItemInfo = null;
if( this.pessimisticLocking ) {
workItemInfo = this.em.find( WorkItemInfo.class, id, LockModeType.PESSIMISTIC_FORCE_INCREMENT );
TransactionManagerHelper.addToUpdatableSet(txm, workItemInfo);
return workItemInfo;
}
workItemInfo = em.find( WorkItemInfo.class, id );
TransactionManagerHelper.addToUpdatableSet(txm, workItemInfo);
return workItemInfo;
}
public void remove(WorkItemInfo workItemInfo) {
em.remove( workItemInfo );
TransactionManagerHelper.removeFromUpdatableSet(txm, workItemInfo);
}
public WorkItemInfo merge(WorkItemInfo workItemInfo) {
if( this.pessimisticLocking ) {
if( em.contains(workItemInfo) ) {
em.lock(workItemInfo, LockModeType.PESSIMISTIC_FORCE_INCREMENT);
} else {
// Yes, this is a hack, but for detached entities, it's the only way to lock before merging
WorkItemInfo dbWorkItemInfo = em.find(WorkItemInfo.class, workItemInfo.getId(), LockModeType.PESSIMISTIC_FORCE_INCREMENT);
for( Field field : WorkItemInfo.class.getDeclaredFields() ) {
boolean access = field.isAccessible();
field.setAccessible(true);
try {
field.set(dbWorkItemInfo, field.get(workItemInfo));
} catch (Exception e) {
logger.error("Unable to set field " + field.getName() + " of unmerged WorkItemInfo instance!", e);
}
field.setAccessible(access);
}
}
}
TransactionManagerHelper.addToUpdatableSet(txm, workItemInfo);
return em.merge( workItemInfo );
}
public void lock(WorkItemInfo workItemInfo) {
this.em.lock( workItemInfo, LockModeType.PESSIMISTIC_FORCE_INCREMENT );
}
protected EntityManager getEntityManager() {
return this.em;
}
}