/*
* 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.openejb.core.cmp.cmp2;
import org.apache.openejb.BeanContext;
import org.apache.openejb.loader.SystemInstance;
import javax.ejb.EJBException;
import javax.ejb.EJBLocalObject;
import javax.ejb.EntityBean;
import javax.transaction.Synchronization;
import javax.transaction.TransactionSynchronizationRegistry;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Collections;
import java.util.ConcurrentModificationException;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
public class CmrSet<Bean extends EntityBean, Proxy extends EJBLocalObject> extends AbstractSet {
private final EntityBean source;
private final String sourceProperty;
private final BeanContext relatedInfo;
private final String relatedProperty;
private final Class relatedLocal;
private boolean mutable = true;
private Collection<Bean> relatedBeans;
public CmrSet(final EntityBean source, final String sourceProperty, final BeanContext relatedInfo, final String relatedProperty, final Collection<Bean> relatedBeans) {
this.source = source;
this.sourceProperty = sourceProperty;
this.relatedInfo = relatedInfo;
this.relatedProperty = relatedProperty;
this.relatedBeans = relatedBeans;
relatedLocal = relatedInfo.getLocalInterface();
final TransactionSynchronizationRegistry transactionRegistry = SystemInstance.get().getComponent(TransactionSynchronizationRegistry.class);
try {
transactionRegistry.registerInterposedSynchronization(new Synchronization() {
public void beforeCompletion() {
}
public void afterCompletion(final int i) {
mutable = false;
}
});
} catch (final IllegalStateException ignored) {
// no tx so not mutable
mutable = false;
}
}
protected void entityDeleted() {
relatedBeans = null;
mutable = false;
}
public boolean isEmpty() {
return getRelatedBeans(false, false).isEmpty();
}
public int size() {
return getRelatedBeans(false, false).size();
}
public boolean contains(final Object o) {
if (relatedLocal.isInstance(o)) {
final Bean entity = getEntityBean((EJBLocalObject) o);
return entity != null && getRelatedBeans(false, false).contains(entity);
}
return false;
}
public boolean addAll(final Collection c) {
final Set<Bean> entityBeans = getEntityBeans(c, relatedLocal);
boolean changed = false;
for (final Iterator<Bean> iterator = entityBeans.iterator(); iterator.hasNext(); ) {
final Bean bean = iterator.next();
changed = add(bean) || changed;
}
return changed;
}
public boolean add(final Object proxy) {
if (!relatedLocal.isInstance(proxy)) {
throw new IllegalArgumentException("Object is not an instance of " + relatedLocal.getName() +
": " + (proxy == null ? "null" : proxy.getClass().getName()));
}
final Bean newEntity = getEntityBean((EJBLocalObject) proxy);
if (newEntity == null) {
throw new IllegalArgumentException("Ejb has been deleted");
}
return add(newEntity);
}
private boolean add(final Bean newEntity) {
final boolean changed = getRelatedBeans(true, true).add(newEntity);
if (changed && relatedProperty != null) {
// set the back reference in the new related bean
if (source == null) {
throw new IllegalStateException("source is null");
}
final Object oldBackRef = toCmp2Entity(newEntity).OpenEJB_addCmr(relatedProperty, source);
// if the new related beas was related to another bean, we need
// to clear the back reference in that old bean
if (oldBackRef != null) {
toCmp2Entity(oldBackRef).OpenEJB_removeCmr(sourceProperty, newEntity);
}
}
return changed;
}
public boolean remove(final Object o) {
if (!relatedLocal.isInstance(o)) {
return false;
}
final Bean entity = getEntityBean((EJBLocalObject) o);
final boolean changed = entity != null && getRelatedBeans(false, true).remove(entity);
if (changed && relatedProperty != null) {
toCmp2Entity(entity).OpenEJB_removeCmr(relatedProperty, source);
}
return changed;
}
public boolean retainAll(final Collection c) {
final Set entityBeans = getEntityBeans(c, null);
boolean changed = false;
for (final Iterator<Bean> iterator = getRelatedBeans(false, true).iterator(); iterator.hasNext(); ) {
final Bean entity = iterator.next();
if (!entityBeans.contains(entity)) {
iterator.remove();
if (relatedProperty != null) {
toCmp2Entity(entity).OpenEJB_removeCmr(relatedProperty, source);
}
changed = true;
}
}
return changed;
}
public Iterator<Proxy> iterator() {
return new Iterator<Proxy>() {
private Bean currentEntity;
private Iterator<Bean> iterator = getRelatedBeans(true, false).iterator();
public boolean hasNext() {
return iterator.hasNext();
}
public Proxy next() {
if (relatedBeans == null) {
throw new ConcurrentModificationException("Entity has been deleted therefore this iterator can no longer be used");
}
currentEntity = iterator.next();
return getEjbProxy(currentEntity);
}
public void remove() {
if (relatedBeans == null) {
throw new ConcurrentModificationException("Entity has been deleted therefore this iterator can no longer be used");
}
if (!mutable) {
throw new ConcurrentModificationException("Transaction has completed therefore this cmr collection can no longer be modified");
}
iterator.remove();
if (relatedProperty != null) {
toCmp2Entity(currentEntity).OpenEJB_removeCmr(relatedProperty, source);
}
}
};
}
private Proxy getEjbProxy(final Bean entity) throws EJBException {
if (entity == null) {
return null;
}
final Proxy ejbProxy = Cmp2Util.<Proxy>getEjbProxy(relatedInfo, entity);
return ejbProxy;
}
private Bean getEntityBean(final EJBLocalObject proxy) {
if (proxy == null) {
return null;
}
final Bean bean = Cmp2Util.<Bean>getEntityBean(proxy);
return bean;
}
private static <Bean extends EntityBean> Set<Bean> getEntityBeans(final Collection<?> proxies, final Class type) {
if (proxies == null) {
return null;
}
final Set<Bean> entities = new HashSet<Bean>();
for (final Object value : proxies) {
if (type != null && !type.isInstance(value)) {
throw new IllegalArgumentException("Object is not an instance of " + type.getName() +
": " + (value == null ? "null" : value.getClass().getName()));
}
final Bean entity = Cmp2Util.<Bean>getEntityBean((EJBLocalObject) value);
if (entity == null) {
throw new IllegalArgumentException("Entity has been deleted");
}
entities.add(entity);
}
return entities;
}
private Cmp2Entity toCmp2Entity(final Object object) {
return (Cmp2Entity) object;
}
private Collection<Bean> getRelatedBeans(final boolean mustExist, final boolean mutateOpation) {
if (relatedBeans == null) {
if (mustExist) {
throw new IllegalStateException("Entity has been deleted therefore this cmr collection can no longer be modified");
}
return Collections.emptySet();
}
if (mutateOpation && !mutable) {
throw new IllegalStateException("Transaction has completed therefore this cmr collection can no longer be modified");
}
return relatedBeans;
}
}