org.zkbase.dao.BasicDao.java Source code

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Here is the source code for org.zkbase.dao.BasicDao.java

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/*
 * Copyright 2002-2008 the original author or authors:
 * http://loom.extrema-sistemas.com/
 * http://sourceforge.net/projects/loom/
 *
 * 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 org.zkbase.dao;

import java.io.Serializable;
import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.NoResultException;
import javax.persistence.NonUniqueResultException;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;

import org.springframework.orm.jpa.JpaOperations;
import org.springframework.stereotype.Repository;

/**
 * Common persistence methods
 * @author icoloma
 */
@Repository
public class BasicDao {

    @PersistenceContext
    private EntityManager entityManager;

    /**
     * Retrieves a non-paged query. Use with care, this method could potentially
     * instantiate large amounts of data.
     */
    @SuppressWarnings("unchecked")
    public <T> List<T> find(String queryString, Object... params) {
        //queryString += " order by firstName desc";
        Query query = entityManager.createQuery(queryString);
        setParameters(query, params);
        return query.getResultList();
    }

    /**
     * Retrieves a paged query.
     */
    @SuppressWarnings("unchecked")
    public <T> List<T> find(String queryString, int firstResult, int maxResults, Object... params) {
        Query query = entityManager.createQuery(queryString);
        query.setFirstResult(firstResult);
        query.setMaxResults(maxResults);
        setParameters(query, params);
        return query.getResultList();
    }

    /**
     * @return a single object that satisfies the query.
     * @throws NoResultException
     *             if there is no result
     * @throws NonUniqueResultException
     *             if more than one result
     * @throws IllegalStateException
     *             if called for a Java Persistence query language UPDATE or
     *             DELETE statement
     */
    public Object findSingle(String queryString, Object... params) {
        Query query = entityManager.createQuery(queryString);
        setParameters(query, params);
        return query.getSingleResult();
    }

    /**
     * Sets all the parameters of a query
     */
    private void setParameters(Query query, Object... params) {
        if (params != null) {
            for (int i = 0; i < params.length; i++)
                query.setParameter(i + 1, params[i]);
        }
    }

    public <T> T merge(T entity) {
        return entityManager.merge(entity);
    }

    public void persist(Object entity) {
        entityManager.persist(entity);
    }

    /**
     * Removes a persistent instance
     * 
     * @param <T>
     *            The persistent class
     * @param clazz
     *            The persistent class
     * @param id
     *            the primary key to remove
     * @return the removed instance
     */
    public <T> T remove(Class<T> clazz, Serializable id) throws EntityNotFoundException {
        T instance = find(clazz, id);
        entityManager.remove(instance);
        return instance;
    }

    @SuppressWarnings("unchecked")
    public <T> List<T> findAll(Class<T> clazz, int firstResult, int maxResults) {
        return (List<T>) find("from " + clazz.getName(), firstResult, maxResults);
    }

    @SuppressWarnings("unchecked")
    public <T> List<T> findAll(Class<T> clazz) {
        return (List<T>) find("from " + clazz.getName());
    }

    public <T> Long count(Class<T> clazz) {
        Query query = entityManager.createQuery("SELECT COUNT(o) FROM " + clazz.getName() + " o");
        return (Long) query.getSingleResult();
    }

    public <T> T find(Class<T> clazz, Serializable id) throws EntityNotFoundException {
        T result = entityManager.find(clazz, id);
        if (result == null) {
            throw new EntityNotFoundException(clazz, id);
        }
        return result;
    }

    public void flush() {
        entityManager.flush();
    }

    public EntityManager getEntityManager() {
        return entityManager;
    }

    public void refresh(Object entity) {
        entityManager.refresh(entity);
    }

    /**
     * Retrieves a non-paged query
     */
    @SuppressWarnings("unchecked")
    public <T> List<T> findNamedQuery(final String namedQuery, int firstResult, int maxResult, Object... params) {

        Query query = entityManager.createNamedQuery(namedQuery);
        query.setFirstResult(firstResult);
        query.setMaxResults(maxResult);
        setParameters(query, params);
        return query.getResultList();
    }

    /**
     * @return a single object that satisfies the named query.
     * @throws NoResultException
     *             if there is no result
     * @throws NonUniqueResultException
     *             if more than one result
     * @throws IllegalStateException
     *             if called for a Java Persistence query language UPDATE or
     *             DELETE statement
     */
    public Object findNamedQuerySingle(String namedQuery, Object... params) {
        Query query = entityManager.createNamedQuery(namedQuery);
        setParameters(query, params);
        return query.getSingleResult();
    }

    public int bulkUpdate(String queryString, Object... params) {
        Query query = entityManager.createQuery(queryString);
        setParameters(query, params);
        return query.executeUpdate();
    }
}