package com.avaje.ebeaninternal.server.persist;
import java.util.ArrayList;
import java.util.List;
import com.avaje.ebean.bean.EntityBean;
import com.avaje.ebeaninternal.api.SpiEbeanServer;
import com.avaje.ebeaninternal.api.SpiQuery;
import com.avaje.ebeaninternal.api.SpiTransaction;
import com.avaje.ebeaninternal.server.core.PersistRequestBean;
import com.avaje.ebeaninternal.server.deploy.BeanDescriptor;
import com.avaje.ebeaninternal.server.deploy.BeanPropertyAssocOne;
import com.avaje.ebeaninternal.server.transaction.DefaultPersistenceContext;
/**
* Used for deletion of a partially populated bean where some cascade delete
* properties where not loaded.
* <p>
* This bean effectively holds the foreign properties that where not loaded, and
* helps fetch the foreign keys and delete the appropriate rows.
* </p>
*
* @author rbygrave
*/
public class DeleteUnloadedForeignKeys {
private final List<BeanPropertyAssocOne<?>> propList = new ArrayList<BeanPropertyAssocOne<?>>(4);
private final SpiEbeanServer server;
private final PersistRequestBean<?> request;
private EntityBean beanWithForeignKeys;
public DeleteUnloadedForeignKeys(SpiEbeanServer server, PersistRequestBean<?> request) {
this.server = server;
this.request = request;
}
public boolean isEmpty() {
return propList.isEmpty();
}
public void add(BeanPropertyAssocOne<?> prop) {
propList.add(prop);
}
/**
* Execute a query fetching the missing (unloaded) foreign keys. We need to
* fetch these key values before the parent bean is deleted.
*/
public void queryForeignKeys() {
BeanDescriptor<?> descriptor = request.getBeanDescriptor();
SpiQuery<?> q = (SpiQuery<?>) server.createQuery(descriptor.getBeanType());
Object id = request.getBeanId();
StringBuilder sb = new StringBuilder(30);
for (int i = 0; i < propList.size(); i++) {
sb.append(propList.get(i).getName()).append(",");
}
// run query in a separate persistence context
q.setPersistenceContext(new DefaultPersistenceContext());
q.setAutofetch(false);
q.select(sb.toString());
q.where().idEq(id);
SpiTransaction t = request.getTransaction();
if (t.isLogSummary()) {
t.logSummary("-- Ebean fetching foreign key values for delete of " + descriptor.getName() + " id:" + id);
}
beanWithForeignKeys = (EntityBean)server.findUnique(q, t);
}
/**
* Delete the rows relating to the foreign keys. These deletions occur after
* the parent bean has been deleted.
*/
public void deleteCascade() {
for (int i = 0; i < propList.size(); i++) {
BeanPropertyAssocOne<?> prop = propList.get(i);
Object detailBean = prop.getValue(beanWithForeignKeys);
// if bean exists with a unique id then delete it
if (detailBean != null && prop.hasId((EntityBean)detailBean)) {
server.delete(detailBean, request.getTransaction());
}
}
}
}