Java tutorial
/** * JBoss, Home of Professional Open Source. * Copyright 2014 Red Hat, Inc., and individual contributors * as indicated by the @author tags. * * 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.jboss.pnc.datastore.repositories; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.Map; import javax.inject.Inject; import javax.persistence.EntityManager; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.dialect.Dialect; import org.hibernate.jdbc.ReturningWork; import org.hibernate.jdbc.Work; import org.hibernate.service.jdbc.dialect.internal.StandardDialectResolver; import org.hibernate.service.jdbc.dialect.spi.DialectResolver; public class SequenceHandlerRepository { public SequenceHandlerRepository() { } private EntityManager entityManager; private Map<String, Object> entityManagerFactoryProperties; @Inject public SequenceHandlerRepository(EntityManager entityManager) { this.entityManager = entityManager; this.entityManagerFactoryProperties = entityManager.getEntityManagerFactory().getProperties(); } public String getEntityManagerFactoryProperty(String propertyName) { for (Map.Entry<String, Object> e : entityManagerFactoryProperties.entrySet()) { if (e.getKey().trim().equals(propertyName)) { return e.getValue().toString(); } } return null; } public Long getNextID(final String sequenceName) { ReturningWork<Long> maxReturningWork = new ReturningWork<Long>() { @Override public Long execute(Connection connection) throws SQLException { DialectResolver dialectResolver = new StandardDialectResolver(); Dialect dialect = dialectResolver.resolveDialect(connection.getMetaData()); PreparedStatement preparedStatement = null; ResultSet resultSet = null; try { preparedStatement = connection.prepareStatement(dialect.getSequenceNextValString(sequenceName)); resultSet = preparedStatement.executeQuery(); resultSet.next(); return resultSet.getLong(1); } catch (SQLException e) { throw e; } finally { if (preparedStatement != null) { preparedStatement.close(); } if (resultSet != null) { resultSet.close(); } } } }; Session session = (Session) entityManager.getDelegate(); SessionFactory sessionFactory = session.getSessionFactory(); Long maxRecord = sessionFactory.getCurrentSession().doReturningWork(maxReturningWork); return maxRecord; } public void createSequence(final String sequenceName) { if (sequenceExists(sequenceName)) { return; } Work work = new Work() { @Override public void execute(Connection connection) throws SQLException { DialectResolver dialectResolver = new StandardDialectResolver(); Dialect dialect = dialectResolver.resolveDialect(connection.getMetaData()); PreparedStatement preparedStatement = null; ResultSet resultSet = null; try { preparedStatement = connection .prepareStatement(dialect.getCreateSequenceStrings(sequenceName, 1, 1)[0]); preparedStatement.execute(); } catch (SQLException e) { throw e; } finally { if (preparedStatement != null) { preparedStatement.close(); } if (resultSet != null) { resultSet.close(); } } } }; Session session = (Session) entityManager.getDelegate(); SessionFactory sessionFactory = session.getSessionFactory(); sessionFactory.getCurrentSession().doWork(work); } public boolean sequenceExists(final String sequenceName) { ReturningWork<Boolean> work = new ReturningWork<Boolean>() { @Override public Boolean execute(Connection connection) throws SQLException { DialectResolver dialectResolver = new StandardDialectResolver(); Dialect dialect = dialectResolver.resolveDialect(connection.getMetaData()); PreparedStatement preparedStatement = null; ResultSet resultSet = null; try { preparedStatement = connection.prepareStatement(dialect.getQuerySequencesString()); resultSet = preparedStatement.executeQuery(); while (resultSet.next()) { if (sequenceName.equals(resultSet.getString(1))) { return true; } } } catch (SQLException e) { throw e; } finally { if (preparedStatement != null) { preparedStatement.close(); } if (resultSet != null) { resultSet.close(); } } return false; } }; Session session = (Session) entityManager.getDelegate(); SessionFactory sessionFactory = session.getSessionFactory(); return sessionFactory.getCurrentSession().doReturningWork(work); } public void dropSequence(final String sequenceName) { Work work = new Work() { @Override public void execute(Connection connection) throws SQLException { DialectResolver dialectResolver = new StandardDialectResolver(); Dialect dialect = dialectResolver.resolveDialect(connection.getMetaData()); PreparedStatement preparedStatement = null; ResultSet resultSet = null; try { preparedStatement = connection .prepareStatement(dialect.getDropSequenceStrings(sequenceName)[0]); preparedStatement.execute(); } catch (SQLException e) { throw e; } finally { if (preparedStatement != null) { preparedStatement.close(); } if (resultSet != null) { resultSet.close(); } } } }; Session session = (Session) entityManager.getDelegate(); SessionFactory sessionFactory = session.getSessionFactory(); sessionFactory.getCurrentSession().doWork(work); } }