Java tutorial
/* Copyright 2012 Tim Garrett, Mothsoft LLC * * 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 com.mothsoft.alexis.dao; import java.util.Date; import java.util.List; import javax.persistence.EntityManager; import javax.persistence.PersistenceContext; import javax.persistence.Query; import org.springframework.stereotype.Repository; import com.mothsoft.alexis.domain.RssFeed; @Repository public class RssFeedDaoImpl implements RssFeedDao { @PersistenceContext private EntityManager em; public void setEm(final EntityManager em) { this.em = em; } public void add(final RssFeed rssFeed) { this.em.persist(rssFeed); } public RssFeed findByUrl(String url) { final Query query = this.em.createQuery("FROM RssFeed WHERE url = :url"); query.setParameter("url", url); @SuppressWarnings("unchecked") final List<RssFeed> results = query.getResultList(); if (results.size() == 1) { return results.get(0); } return null; } @SuppressWarnings("unchecked") public List<RssFeed> listRssFeedsWithRetrievalDateMoreThanXMinutesAgo(int minutes) { final Date now = new Date(); final int minutesInMilliseconds = minutes * 60 * 1000; final Date minutesAgo = new Date(now.getTime() - minutesInMilliseconds); final List<RssFeed> feeds = this.em.createQuery( "FROM RssFeed f WHERE f.retrievalDate IS NULL OR f.retrievalDate < :minutesAgo ORDER BY id ASC") .setParameter("minutesAgo", minutesAgo).getResultList(); return feeds; } public void remove(final RssFeed rssFeed) { this.em.remove(rssFeed); } public void update(final RssFeed rssFeed) { this.em.merge(rssFeed); } }