Metacat

/**

 *  '$RCSfile$'

 *    Purpose: Implements a service for managing a Hazelcast cluster member

 *  Copyright: 2013 Regents of the University of California and the

 *             National Center for Ecological Analysis and Synthesis

 *    Authors: Leinfelder

 * 

 *   '$Author: tao $'

 *     '$Date: 2013-09-27 16:44:08 -0700 (Fri, 27 Sep 2013) $'

 * '$Revision: 8268 $'

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

package edu.ucsb.nceas.metacat.index;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Timestamp;

import java.util.Set;

import java.util.TreeSet;

import org.dataone.service.types.v1.Event;

import org.dataone.service.types.v1.Identifier;

import edu.ucsb.nceas.metacat.common.index.event.IndexEvent;

import edu.ucsb.nceas.metacat.database.DBConnection;

import edu.ucsb.nceas.metacat.database.DBConnectionPool;

public class IndexEventDAO {

	private static IndexEventDAO instance = null;

	private static String DELETESQL = "delete from index_event where guid = ?";

	private IndexEventDAO() {}

	public static IndexEventDAO getInstance() {

		if (instance == null) {

			instance = new IndexEventDAO();

		}

		return instance;

	}

	public void add(IndexEvent event) throws SQLException {

		String sql = "insert into index_event(guid, event_action, description, event_date) values (?, ?, ?, ?)";

		DBConnection dbConn = null;

		int serialNumber = -1;

		try {

			// Get a database connection from the pool

			dbConn = DBConnectionPool.getDBConnection("IndexEventDAO.add");

			dbConn.setAutoCommit(false);

			serialNumber = dbConn.getCheckOutSerialNumber();

			//delete the existing event first, because we don't want the table keeps expanding.

			if(event != null && event.getIdentifier() != null && 

			             event.getIdentifier().getValue() != null && 

			             !event.getIdentifier().getValue().trim().equals("")) {

			    PreparedStatement deleteStmt = dbConn.prepareStatement(DELETESQL);

			    deleteStmt.setString(1, event.getIdentifier().getValue());

			    deleteStmt.execute();

			    deleteStmt.close();	    

			}

			// Execute the statement

			PreparedStatement stmt = dbConn.prepareStatement(sql);

			stmt.setString(1, event.getIdentifier().getValue());

			stmt.setString(2, event.getAction().xmlValue());

			stmt.setString(3, event.getDescription());

			stmt.setTimestamp(4, new Timestamp(event.getDate().getTime()));

			stmt.executeUpdate();

			stmt.close();

			dbConn.commit();

		} catch (SQLException sqle) {

            try {

                if(dbConn != null) {

                    //roll back if something happens

                    dbConn.rollback();

                } 

            } catch (SQLException sqle2) {

               throw new SQLException("Metacat can't roll back the change since " +sqle2.getMessage(), sqle);

            }

            throw sqle;

		} finally {

			// Return database connection to the pool

		    dbConn.setAutoCommit(true);

			DBConnectionPool.returnDBConnection(dbConn, serialNumber);

		}

	}

	public void remove(Identifier identifier) throws SQLException {

		DBConnection dbConn = null;

		int serialNumber = -1;

		try {

			// Get a database connection from the pool

			dbConn = DBConnectionPool.getDBConnection("IndexEventDAO.remove");

			serialNumber = dbConn.getCheckOutSerialNumber();

			// Execute the statement

			PreparedStatement stmt = dbConn.prepareStatement(DELETESQL);

			stmt.setString(1, identifier.getValue());

			stmt.execute();

			stmt.close();

		} finally {

			// Return database connection to the pool

			DBConnectionPool.returnDBConnection(dbConn, serialNumber);

		}

	}

	public IndexEvent get(Identifier identifier) throws SQLException {

		IndexEvent event = null;

		String sql = "select guid, event_action, description, event_date from index_event where guid = ?";

		DBConnection dbConn = null;

		int serialNumber = -1;

		try {

			// Get a database connection from the pool

			dbConn = DBConnectionPool.getDBConnection("IndexEventDAO.get");

			serialNumber = dbConn.getCheckOutSerialNumber();

			// Execute the statement

			PreparedStatement stmt = dbConn.prepareStatement(sql);

			stmt.setString(1, identifier.getValue());

			ResultSet rs = stmt.executeQuery();

			while (rs.next()) {

				//String guid = rs.getString(1);

				String action = rs.getString(2);

				String description = rs.getString(3);

				Timestamp timestamp = rs.getTimestamp(4);

				event = new IndexEvent();

				event.setIdentifier(identifier);

				event.setAction(Event.convert(action));

				event.setDate(timestamp);

				event.setDescription(description);

			}

			stmt.close();

		} finally {

			// Return database connection to the pool

			DBConnectionPool.returnDBConnection(dbConn, serialNumber);

		}

		return event;

	}

	public Set<Identifier> getAllIdentifiers() throws SQLException {

		Set<Identifier> identifiers = new TreeSet<Identifier>();

		String sql = "select guid from index_event";

		DBConnection dbConn = null;

		int serialNumber = -1;

		try {

			// Get a database connection from the pool

			dbConn = DBConnectionPool.getDBConnection("IndexEventDAO.getAllIdentifiers");

			serialNumber = dbConn.getCheckOutSerialNumber();

			// Execute the statement

			PreparedStatement stmt = dbConn.prepareStatement(sql);

			ResultSet rs = stmt.executeQuery();

			while (rs.next()) {

				String guid = rs.getString(1);

				Identifier identifier = new Identifier();

				identifier.setValue(guid);

				identifiers.add(identifier);

			}

			stmt.close();

		} finally {

			// Return database connection to the pool

			DBConnectionPool.returnDBConnection(dbConn, serialNumber);

		}

		return identifiers;

	}

}