au.id.wolfe.fxassetman.server.dao.jpa.GenericDaoImpl.java Source code

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Here is the source code for au.id.wolfe.fxassetman.server.dao.jpa.GenericDaoImpl.java

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/**
 *
 * Copyright (C) 2010 markw <mark@wolfe.id.au>
 *
 * Licensed 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 au.id.wolfe.fxassetman.server.dao.jpa;

import java.io.Serializable;
import java.util.Set;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import au.id.wolfe.fxassetman.server.dao.GenericDao;
import au.id.wolfe.fxassetman.server.util.PaginatedResult;

import com.google.common.collect.Sets;

public abstract class GenericDaoImpl<T, PK extends Serializable> implements GenericDao<T, PK> {

    private Class<T> type;

    public GenericDaoImpl(Class<T> type) {
        this.type = type;
    }

    @PersistenceContext
    private EntityManager entityManager;

    /**
     * Get the entity manager associated with this DAO.
     * @return Entity manager instance.
     */
    public EntityManager getEntityManager() {
        return entityManager;
    }

    /**
     * @param entityManager
     *            the entityManager to set
     */
    public void setEntityManager(EntityManager entityManager) {
        this.entityManager = entityManager;
    }

    @Override
    public T update(T entity) {
        return entityManager.merge(entity);
    }

    @Override
    public void save(T entity) {
        entityManager.persist(entity);

    }

    @Override
    public void removeById(PK entityId) {
        entityManager.createQuery("DELETE FROM " + type.getName() + " e WHERE e.id = :entityId")
                .setParameter("entityId", entityId).executeUpdate();

    }

    @Override
    @SuppressWarnings("unchecked")
    public T findById(PK entityId) {
        return (T) entityManager.createQuery("SELECT e FROM " + type.getName() + " e WHERE e.id = :entityId")
                .setParameter("entityId", entityId).getSingleResult();
    }

    @Override
    @SuppressWarnings("unchecked")
    public PaginatedResult<T> findAll(int start, int limit) {
        Set<T> resultSet = Sets.newLinkedHashSet(entityManager.createQuery("SELECT e FROM " + type.getName() + " e")
                .setFirstResult(start).setMaxResults(limit).getResultList());

        PaginatedResult<T> paginatedResult = new PaginatedResult<T>(type);

        Long totalCount = (Long) entityManager.createQuery("select count(o) from " + type.getName() + " as o")
                .getSingleResult();

        paginatedResult.setTotalRecords(totalCount);
        paginatedResult.setResultSet(resultSet);

        return paginatedResult;
    }

    @Override
    @SuppressWarnings("unchecked")
    public Set<T> findAll() {
        return Sets.newLinkedHashSet(
                entityManager.createQuery("SELECT e FROM " + type.getName() + " e").getResultList());
    }

}