source: VirtualCollectionRegistry/trunk/VirtualCollectionRegistry/src/main/java/eu/clarin/cmdi/virtualcollectionregistry/DataStore.java @ 241

package eu.clarin.cmdi.virtualcollectionregistry;

import java.util.Map;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class DataStore {
        private class ThreadLocalEntityManager extends ThreadLocal<EntityManager> {
                protected EntityManager initialValue() {
                        if (emf == null) {
                                throw new InternalError("JPA not initalizied correctly");
                        }
                        return emf.createEntityManager();
                }
        } // inner class ThreadLocalEntityManager
        private static final Logger logger =
                LoggerFactory.getLogger(DataStore.class);
        private final EntityManagerFactory emf;
        private final ThreadLocalEntityManager em = new ThreadLocalEntityManager();

        DataStore(Map<String, String> config)
                throws VirtualCollectionRegistryException {
                try {
                        emf = Persistence.createEntityManagerFactory(
                                        "VirtualCollectionStore", config);
                } catch (Exception e) {
                        logger.error("error initializing data store", e);
                        throw new VirtualCollectionRegistryException("error initializing",
                                        e);
                }
                logger.debug("data store was successfully initialized");
        }

        public void destroy() throws VirtualCollectionRegistryException {
                if (emf != null) {
                        emf.close();
                }
        }

        public EntityManager getEntityManager() {
                return em.get();
        }
        
        public void closeEntityManager() {
                EntityManager manager = em.get();
                if (manager != null) {
                        em.remove();
                        EntityTransaction tx = manager.getTransaction();
                        if (tx.isActive()) {
                                tx.rollback();
                        }
                        manager.close();
                }
        }

} // class DataStore