fr.keyconsulting.oliphant.postgresql.PostgreSQLNotifyListener.java Source code

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Here is the source code for fr.keyconsulting.oliphant.postgresql.PostgreSQLNotifyListener.java

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/*******************************************************************************
    
   Copyright (C) 2009-2010 Key Consulting
    
   This file is part of Oliphant.
    
   Oliphant is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as published
   by the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
    
   Oliphant 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 Lesser General Public License for more details.
    
   You should have received a copy of the GNU Lesser General Public
   License along with Oliphant.  If not, see <http://www.gnu.org/licenses/>.
    
*******************************************************************************/

package fr.keyconsulting.oliphant.postgresql;

import java.util.ArrayList;
import java.util.List;

import org.hibernate.HibernateException;
import org.hibernate.cfg.Configuration;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;
import java.sql.DriverManager;
import org.postgresql.PGNotification;
import org.postgresql.PGConnection;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import fr.keyconsulting.oliphant.Notification;
import fr.keyconsulting.oliphant.SpecificNotifyListener;

public class PostgreSQLNotifyListener implements SpecificNotifyListener {
    private PGConnection pgConn;
    private Connection conn;
    private Configuration config;

    private static final Logger LOG = LoggerFactory.getLogger(PostgreSQLNotifyListener.class);

    public void prepare(Configuration cfg) {
        config = cfg;
        config.addAuxiliaryDatabaseObject(new PostgreSQLListenerAuxiliary(config));
    }

    public void setUp() {
        try {
            conn = DriverManager.getConnection(config.getProperty("hibernate.connection.url"),
                    config.getProperty("hibernate.connection.username"),
                    config.getProperty("hibernate.connection.password"));
            pgConn = (PGConnection) conn;
            Statement stmt = conn.createStatement();
            stmt.execute("LISTEN oliphant");
            stmt.close();
        } catch (SQLException sqle) {
            throw new HibernateException(sqle);
        }
    }

    public List<Notification> getLatestUpdates() {
        List<Notification> notifs = new ArrayList<Notification>();

        try {
            // issue a dummy query to contact the backend and receive any pending notifications.
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT 1");
            rs.close();
            stmt.close();

            PGNotification notifications[] = pgConn.getNotifications();
            if (notifications != null) {
                for (int i = 0; i < notifications.length; i++) {
                    LOG.debug("Notif from PostgreSQL : " + notifications[i].getParameter());
                    notifs.add(new Notification(notifications[i].getParameter().split("###")));
                }
            }
        } catch (SQLException sqle) {
            throw new HibernateException(sqle);
        }

        return notifs;
    }

    public void tearDown() {
        try {
            conn.close();
        } catch (SQLException sqle) {
            throw new HibernateException(sqle);
        }
    }
}