org.usergrid.mongo.commands.MongoCommand.java Source code

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Here is the source code for org.usergrid.mongo.commands.MongoCommand.java

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/*******************************************************************************
 * Copyright (c) 2010, 2011 Ed Anuff and Usergrid, all rights reserved.
 * http://www.usergrid.com
 * 
 * This file is part of Usergrid Stack.
 * 
 * Usergrid Stack is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Affero General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your option)
 * any later version.
 * 
 * Usergrid Stack 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 Affero General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Affero General Public License along
 * with Usergrid Stack. If not, see <http://www.gnu.org/licenses/>.
 * 
 * Additional permission under GNU AGPL version 3 section 7
 * 
 * Linking Usergrid Stack statically or dynamically with other modules is making
 * a combined work based on Usergrid Stack. Thus, the terms and conditions of the
 * GNU General Public License cover the whole combination.
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 * In addition, as a special exception, the copyright holders of Usergrid Stack
 * give you permission to combine Usergrid Stack with free software programs or
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 * that communicate with Usergrid Stack solely through:
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package org.usergrid.mongo.commands;

import java.util.concurrent.ConcurrentHashMap;

import org.apache.log4j.Logger;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.MessageEvent;
import org.springframework.util.StringUtils;
import org.usergrid.mongo.MongoChannelHandler;
import org.usergrid.mongo.protocol.OpQuery;
import org.usergrid.mongo.protocol.OpReply;

public abstract class MongoCommand {

    private static final Logger logger = Logger.getLogger(MongoCommand.class);

    static ConcurrentHashMap<String, MongoCommand> commands = new ConcurrentHashMap<String, MongoCommand>();

    @SuppressWarnings("unchecked")
    public static MongoCommand getCommand(String commandName) {
        MongoCommand command = commands.get(commandName);
        if (command != null) {
            return command;
        }

        String clazz = "org.usergrid.mongo.commands." + StringUtils.capitalize(commandName);

        Class<MongoCommand> cls = null;

        try {
            cls = (Class<MongoCommand>) Class.forName(clazz);
        } catch (ClassNotFoundException e) {
            logger.error("Couldn't find command class", e);
        }

        try {
            if (cls != null) {
                command = cls.newInstance();
            }
        } catch (Exception e) {
            logger.error("Couldn't find instantiate class", e);
        }

        if (command != null) {
            MongoCommand oldCommand = commands.putIfAbsent(commandName, command);
            if (oldCommand != null) {
                command = oldCommand;
            }
        } else {
            logger.warn("Mongo command handler not found for " + commandName);
        }

        return command;
    }

    public abstract OpReply execute(MongoChannelHandler handler, ChannelHandlerContext ctx, MessageEvent e,
            OpQuery opQuery);

}