org.jboss.seam.framework.EntityHome Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jboss-seam Show documentation
Seam core module for Seam framework integrated with JSF2
There is a newer version: 3.2.26.ayg
package org.jboss.seam.framework;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.transaction.SystemException;

import org.jboss.seam.annotations.Transactional;
import org.jboss.seam.persistence.PersistenceProvider;
import org.jboss.seam.transaction.Transaction;

/**
 * Base class for Home objects of JPA entities.
 * 
 * @author Gavin King
 *
 */
public class EntityHome extends Home {
	private static final long serialVersionUID = -3140094990727574632L;

	
	public EntityHome() {
		super();
	}
	
	/**
	* Run on {@link EntityHome} instantiation.
	* 

	* Validates that an {@link EntityManager} is available.
	* 
	* @see Home#create()
	*/
	@Override
	public void create() {
		super.create();
		if (getEntityManager() == null) {
			throw new IllegalStateException("entityManager is null");
		}
	}

	/**
	* Returns true if the entity instance is managed
	*/
	@Transactional
	public boolean isManaged() {
		return getInstance() != null && getEntityManager().contains(getInstance());
	}

	/**
	* Flush any changes made to the managed entity instance to the underlying
	* database. 
	* 

	* If the update is successful, a log message is printed, a 
	* {@link javax.faces.application.FacesMessage} is added and a transaction 
	* success event raised.
	* 
	* @see Home#updatedMessage()
	* @see Home#raiseAfterTransactionSuccessEvent()
	* 
	* @return "updated" if the update is successful
	*/
	@Transactional
	public String update() {
		joinTransaction();
		getEntityManager().flush();
		updatedMessage();
		raiseAfterTransactionSuccessEvent();
		return "updated";
	}

	/**
	* Persist unmanaged entity instance to the underlying database. 
	* If the persist is successful, a log message is printed, a 
	* {@link javax.faces.application.FacesMessage } is added and a transaction 
	* success event raised.
	* 
	* @see Home#createdMessage()
	* @see Home#raiseAfterTransactionSuccessEvent()
	* 
	* @return "persisted" if the persist is successful
	*/
	@Transactional
	public String persist() {
		getEntityManager().persist(getInstance());
		getEntityManager().flush();
		assignId(PersistenceProvider.instance().getId(getInstance(), getEntityManager()));
		createdMessage();
		raiseAfterTransactionSuccessEvent();
		return "persisted";
	}

	/**
	* Remove managed entity instance from the Persistence Context and the 
	* underlying database.
	* If the remove is successful, a log message is printed, a 
	* {@link javax.faces.application.FacesMessage} is added and a transaction 
	* success event raised.
	* 
	* @see Home#deletedMessage()
	* @see Home#raiseAfterTransactionSuccessEvent()
	* 
	* @return "removed" if the remove is successful
	*/
	@Transactional
	public String remove() {
		getEntityManager().remove(getInstance());
		getEntityManager().flush();
		deletedMessage();
		raiseAfterTransactionSuccessEvent();
		return "removed";
	}

	/**
	* Implementation of {@link Home#find() find()} for JPA
	* 
	* @see Home#find()
	*/
	@Transactional
	@Override
	public E find() {
		if (getEntityManager().isOpen()) {
			E result = loadInstance();
			if (result == null) {
				result = handleNotFound();
			}
			return result;
		} else {
			return null;
		}
	}

	/**
	* Utility method to load entity instance from the {@link EntityManager}. 
	* Called by {@link #find()}.
	* 

	* Can be overridden to support eager fetching of associations.
	* 
	* @return The entity identified by {@link Home#getEntityClass() getEntityClass()}, 
	* {@link Home#getId() getId()}
	*/
	protected E loadInstance() {
		return getEntityManager().find(getEntityClass(), getId());
	}

	/**
	* Implementation of {@link Home#joinTransaction() joinTransaction()} for
	* JPA.
	*/
	@Override
	protected void joinTransaction() {
		if (getEntityManager().isOpen()) {
			try {
				Transaction.instance().enlist(getEntityManager());
			} catch (SystemException se) {
				throw new RuntimeException("could not join transaction", se);
			}
		}
	}

	/**
	* The Seam Managed Persistence Context used by this Home component
	*/
	public EntityManager getEntityManager() {
		return getPersistenceContext();
	}

	/**
	* The Seam Managed Persistence Context used by this Home component.
	*/
	public void setEntityManager(EntityManager entityManager) {
		setPersistenceContext(entityManager);
	}

	/**
	* The name the Seam component managing the Persistence Context.
	* 

	* Override this or {@link #getEntityManager()} if your persistence context
	* is not named entityManager.
	*/
	@Override
	protected String getPersistenceContextName() {
		final PersistenceContext ctx = getClass().getAnnotation(PersistenceContext.class);
		if (ctx != null) {
			return ctx.name();
		}
		return "entityManager";
	}

	/**
	* Implementation of {@link Home#getEntityName() getEntityName()} for JPA
	* 
	* @see Home#getEntityName()
	*/
	@Override
	protected String getEntityName() {
		try {
			return PersistenceProvider.instance().getName(getInstance(), getEntityManager());
		} catch (IllegalArgumentException e) {
			// Handle that the passed object may not be an entity
			return null;
		}
	}

}