001/*
002 * HA-JDBC: High-Availability JDBC
003 * Copyright (C) 2012  Paul Ferraro
004 *
005 * This program is free software: you can redistribute it and/or modify
006 * it under the terms of the GNU Lesser General Public License as published by
007 * the Free Software Foundation, either version 3 of the License, or
008 * (at your option) any later version.
009 *
010 * This program is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
013 * GNU Lesser General Public License for more details.
014 *
015 * You should have received a copy of the GNU Lesser General Public License
016 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
017 */
018package net.sf.hajdbc.state.distributed;
019
020import net.sf.hajdbc.Database;
021import net.sf.hajdbc.DatabaseCluster;
022import net.sf.hajdbc.distributed.Command;
023import net.sf.hajdbc.state.DatabaseEvent;
024import net.sf.hajdbc.state.StateManager;
025
026/**
027 * @author paul
028 *
029 */
030public abstract class StateCommand<Z, D extends Database<Z>> implements Command<Boolean, StateCommandContext<Z, D>>
031{
032        private static final long serialVersionUID = 8689116981769588205L;
033
034        private final DatabaseEvent event;
035        
036        protected StateCommand(DatabaseEvent event)
037        {
038                this.event = event;
039        }
040        
041        /**
042         * {@inheritDoc}
043         * @see net.sf.hajdbc.distributed.Command#execute(java.lang.Object)
044         */
045        @Override
046        public Boolean execute(StateCommandContext<Z, D> context)
047        {
048                DatabaseCluster<Z, D> cluster = context.getDatabaseCluster();
049                
050                return this.execute(cluster, context.getLocalStateManager(), cluster.getDatabase(this.event.getSource()));
051        }
052
053        protected abstract boolean execute(DatabaseCluster<Z, D> cluster, StateManager stateManager, D database);
054
055        /**
056         * {@inheritDoc}
057         * @see java.lang.Object#toString()
058         */
059        @Override
060        public String toString()
061        {
062                return String.format("%s(%s)", this.getClass().getSimpleName(), this.event);
063        }
064}