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 org.springframework.stereotype.Repository; import com.mothsoft.alexis.domain.Source; @Repository public class SourceDaoImpl implements SourceDao { @PersistenceContext private EntityManager em; public void setEm(EntityManager em) { this.em = em; } public void add(Source source) { this.em.persist(source); } public Source get(Long id) { return this.em.find(Source.class, id); } @SuppressWarnings("unchecked") public List<Source> list(Class<? extends Source> restrictionClass) { final String className = restrictionClass.getCanonicalName(); final List<Source> sources = this.em.createQuery("FROM " + className + " ORDER BY id ASC").getResultList(); return sources; } @SuppressWarnings("unchecked") public List<Source> listSourcesByOwner(Long userId, Class<? extends Source> restrictionClass) { final String className = restrictionClass.getCanonicalName(); final List<Source> sources = this.em .createQuery("FROM " + className + " s WHERE s.userId = :userId ORDER BY id ASC") .setParameter("userId", userId).getResultList(); return sources; } @SuppressWarnings("unchecked") public List<Source> listSourcesWithRetrievalDateMoreThanXMinutesAgo(int minutes, Class<? extends Source> restrictionClass) { final String className = restrictionClass.getCanonicalName(); final Date now = new Date(); final int minutesInMilliseconds = minutes * 60 * 1000; final Date minutesAgo = new Date(now.getTime() - minutesInMilliseconds); final List<Source> sources = this.em .createQuery("FROM " + className + " s WHERE s.retrievalDate IS NULL OR s.retrievalDate < :minutesAgo ORDER BY id ASC") .setParameter("minutesAgo", minutesAgo).getResultList(); return sources; } public void remove(final Source source) { this.em.remove(source); } public void update(final Source source) { this.em.merge(source); } }