DirectPushRemoteWrapper.java

/**
*    Copyright (c) 2011-2014, OpenIoT
*   
*    This file is part of OpenIoT.
*
*    OpenIoT 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, version 3 of the License.
*
*    OpenIoT 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 OpenIoT.  If not, see <http://www.gnu.org/licenses/>.
*
*     Contact: OpenIoT mailto: info@openiot.eu
 * @author Julien Eberle
*/

package org.openiot.gsn.http.rest;

import org.openiot.gsn.beans.DataField;
import org.apache.log4j.Logger;

/**
 * Same as PushRemoteWrapper, but no registration needed to initialize the push stream.
 * The notification id serves as the key to identify the pushed data and the structure has to be defined in the 
 * virtual sensor xml file.
 * This is mostly useful for getting data from network enabled sensors that are not always connected and that may change their 
 * ip address frequently. For example curl can be used to push data. See online documentation for more details.
 * @author jeberle
 *
 */
public class DirectPushRemoteWrapper extends PushRemoteWrapper {

    private final transient Logger logger = Logger.getLogger(DirectPushRemoteWrapper.class);

    private double uid = -1; //statically set from the parameters

    /**
     * get parameters from the address bean
     */
    @Override
    public boolean initialize() {
        try {
            uid = Double.parseDouble(getActiveAddressBean().getPredicateValueWithException(PushDelivery.NOTIFICATION_ID_KEY));
            structure = registerAndGetStructure();
            NotificationRegistry.getInstance().addNotification(uid, this);
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            NotificationRegistry.getInstance().removeNotification(uid);
            return false;
        }
        return true;
    }

    @Override
    public String getWrapperName() {
        return "Direct Push-Remote Wrapper";
    }

    /**
     * if the structure is not defined in the xml file, throws an exception.
     */
    @Override
    public DataField[] registerAndGetStructure() throws RuntimeException{ 
    	DataField[] s = getActiveAddressBean().getOutputStructure();
    	if (s == null){throw new RuntimeException("Direct Push wrapper has an undefined output structure.");}
    	return s;
    }
    
    /**
     * Passive push. We don't actively query the node for new elements.
     */
    @Override
    public void run() {}

}