Java tutorial
/********************************************************************************** * $URL: https://source.sakaiproject.org/svn/search/trunk/search-impl/impl/src/java/org/sakaiproject/search/journal/impl/DbJournalManager.java $ * $Id: DbJournalManager.java 105078 2012-02-24 23:00:38Z ottenhoff@longsight.com $ *********************************************************************************** * * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008 The Sakai Foundation * * Licensed under the Educational Community 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.opensource.org/licenses/ECL-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.sakaiproject.search.journal.impl; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import javax.sql.DataSource; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.sakaiproject.component.api.ServerConfigurationService; import org.sakaiproject.search.indexer.api.IndexJournalException; import org.sakaiproject.search.journal.api.JournalErrorException; import org.sakaiproject.search.journal.api.JournalExhausetedException; import org.sakaiproject.search.journal.api.JournalManager; import org.sakaiproject.search.journal.api.JournalManagerState; import org.sakaiproject.search.transaction.api.IndexTransaction; /** * A database backed Journal Manager * * @author ieb Unit test * @see org.sakaiproject.search.indexer.impl.test.TransactionalIndexWorkerTest * Unit test * @see org.sakaiproject.search.indexer.impl.test.DbJournalManagerTest */ public class DbJournalManager implements JournalManager { /** * @author ieb */ private static class JournalManagerStateImpl implements JournalManagerState { private long transactionId; /* * Normally its not safe to hold onto a connection for any length of * time, but here it is ok since the transaction is connected to the * transaction id. The danger of not detaching is connection is that if * there is a machine failure I dont journal to be update. */ public Connection connection; /** * @param transactionId */ public JournalManagerStateImpl(long transactionId) { this.transactionId = transactionId; } /** * @return the transactionId */ public long getTransactionId() { return transactionId; } } private static final Log log = LogFactory.getLog(DbJournalManager.class); private DataSource datasource; private String serverId; private ServerConfigurationService serverConfigurationService; public void init() { serverId = serverConfigurationService.getServerId(); } public void destroy() { } /** * @return the datasource */ public DataSource getDatasource() { return datasource; } /** * @param datasource * the datasource to set */ public void setDatasource(DataSource datasource) { this.datasource = datasource; } /** * @throws JournalErrorException * @see org.sakaiproject.search.journal.api.JournalManager#getLaterSavePoints(long) */ public long getNextSavePoint(long savePoint) throws JournalErrorException { Connection connection = null; PreparedStatement listLaterSavePoints = null; ResultSet rs = null; try { connection = datasource.getConnection(); listLaterSavePoints = connection.prepareStatement( "select txid from search_journal where txid > ? and (status = 'commited' or status = 'committed') order by txid asc "); listLaterSavePoints.clearParameters(); listLaterSavePoints.setLong(1, savePoint); try { rs = listLaterSavePoints.executeQuery(); if (rs.next()) { return rs.getLong(1); } } catch (Exception ex) { log.warn("Shared Index Optimization in progress, pausing updates to this index :" + ex); } throw new JournalExhausetedException("No More savePoints available"); } catch (SQLException ex) { log.error("Failed to retrieve list of journal items ", ex); throw new JournalErrorException("Journal Error ", ex); } finally { try { rs.close(); } catch (Exception ex) { log.debug(ex); } try { listLaterSavePoints.close(); } catch (Exception ex) { log.debug(ex); } try { connection.close(); } catch (Exception ex) { log.debug(ex); } } } /** * @see org.sakaiproject.search.journal.api.JournalManager#prepareSave(long) */ public JournalManagerState prepareSave(long transactionId) throws IndexJournalException { PreparedStatement insertPst = null; JournalManagerStateImpl jms = new JournalManagerStateImpl(transactionId); try { Connection connection = datasource.getConnection(); jms.connection = connection; insertPst = connection.prepareStatement( "insert into search_journal (txid, txts, indexwriter, status) values ( ?,?,?,?)"); insertPst.clearParameters(); insertPst.setLong(1, transactionId); insertPst.setLong(2, System.currentTimeMillis()); insertPst.setString(3, serverId); insertPst.setString(4, "prepare"); if (insertPst.executeUpdate() != 1) { throw new IndexJournalException("Failed to update index journal"); } } catch (IndexJournalException ijex) { throw ijex; } catch (Exception ex) { throw new IndexJournalException("Failed to transfer index ", ex); } finally { try { insertPst.close(); } catch (Exception ex) { log.debug(ex); } } return jms; } /** * @see org.sakaiproject.search.journal.api.JournalManager#commitSave() */ public void commitSave(JournalManagerState jms) throws IndexJournalException { Connection connection = ((JournalManagerStateImpl) jms).connection; PreparedStatement success = null; try { success = connection.prepareStatement("update search_journal set status = 'committed' where txid = ? "); success.clearParameters(); success.setLong(1, ((JournalManagerStateImpl) jms).getTransactionId()); if (success.executeUpdate() != 1) { throw new IndexJournalException("Failed to update index journal"); } connection.commit(); } catch (Exception ex) { try { connection.rollback(); } catch (Exception ex2) { log.debug(ex); } throw new IndexJournalException("Failed to commit index ", ex); } finally { try { success.close(); } catch (Exception ex) { log.debug(ex); } try { connection.close(); } catch (Exception ex) { log.debug(ex); } } } /** * @see org.sakaiproject.search.journal.api.JournalManager#rollbackSave(org.sakaiproject.search.journal.api.JournalManagerState) */ public void rollbackSave(JournalManagerState jms) { if (jms != null) { Connection connection = ((JournalManagerStateImpl) jms).connection; try { connection.rollback(); } catch (Exception ex) { log.error("Failed to Rollback"); } finally { try { connection.close(); } catch (Exception ex) { log.debug(ex); } } } } /* * (non-Javadoc) * * @see org.sakaiproject.search.journal.api.JournalManager#doOpenTransaction(org.sakaiproject.search.transaction.api.IndexTransaction) */ public void doOpenTransaction(IndexTransaction transaction) { } /** * @return the serverConfigurationService */ public ServerConfigurationService getServerConfigurationService() { return serverConfigurationService; } /** * @param serverConfigurationService * the serverConfigurationService to set */ public void setServerConfigurationService(ServerConfigurationService serverConfigurationService) { this.serverConfigurationService = serverConfigurationService; } }