SearchResponse.java

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 * Licensed under the Apache License, Version 2.0 (the "License");
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 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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/*
    Calimero - A library for KNX network access
    Copyright (C) 2005 Bernhard Erb
    Copyright (C) 2006-2008 B. Malinowsky

    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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA. 
 
    Linking this library statically or dynamically with other modules is 
    making a combined work based on this library. Thus, the terms and 
    conditions of the GNU General Public License cover the whole 
    combination. 
 
    As a special exception, the copyright holders of this library give you 
    permission to link this library with independent modules to produce an 
    executable, regardless of the license terms of these independent 
    modules, and to copy and distribute the resulting executable under terms 
    of your choice, provided that you also meet, for each linked independent 
    module, the terms and conditions of the license of that module. An 
    independent module is a module which is not derived from or based on 
    this library. If you modify this library, you may extend this exception 
    to your version of the library, but you are not obligated to do so. If 
    you do not wish to do so, delete this exception statement from your 
    version. 
*/

package tuwien.auto.calimero.knxnetip.servicetype;

import java.io.ByteArrayOutputStream;

import tuwien.auto.calimero.exception.KNXFormatException;
import tuwien.auto.calimero.knxnetip.util.DeviceDIB;
import tuwien.auto.calimero.knxnetip.util.HPAI;
import tuwien.auto.calimero.knxnetip.util.SuppFamiliesDIB;

/**
 * Represents a KNXnet/IP search response.
 * <p>
 * Such a response is used during device discovery and sent in reply to a search request.
 * It contains one server control endpoint and self description of the server device.<br>
 * An answering server, supporting more than one KNX connections at the same time, sends a
 * single search response for each of its control endpoints, i.e. one response for one
 * control endpoint.
 * <p>
 * Objects of this type are immutable.
 * 
 * @author Bernhard Erb
 * @author B. Malinowsky
 * @see tuwien.auto.calimero.knxnetip.servicetype.SearchRequest
 */
public class SearchResponse extends ServiceType
{
	private final HPAI endpt;
	private final DescriptionResponse desc;

	/**
	 * Creates a new search response out of a byte array.
	 * <p>
	 * 
	 * @param data byte array containing a search response structure
	 * @param offset start offset of response in <code>data</code>
	 * @throws KNXFormatException if no search response was found or invalid structure
	 */
	public SearchResponse(byte[] data, int offset) throws KNXFormatException
	{
		super(KNXnetIPHeader.SEARCH_RES);
		endpt = new HPAI(data, offset);
		desc = new DescriptionResponse(data, offset + endpt.getStructLength());
	}

	/**
	 * Creates a new search response for the given control endpoint together with device
	 * information.
	 * <p>
	 * 
	 * @param ctrlEndpoint discovered control endpoint of the server sending this response
	 * @param device server device description information
	 * @param svcFamilies supported service families by the server
	 */
	public SearchResponse(HPAI ctrlEndpoint, DeviceDIB device, SuppFamiliesDIB svcFamilies)
	{
		super(KNXnetIPHeader.SEARCH_RES);
		endpt = ctrlEndpoint;
		desc = new DescriptionResponse(device, svcFamilies);
	}

	/**
	 * Returns the server control endpoint.
	 * <p>
	 * 
	 * @return discovered control endpoint in a HPAI
	 */
	public final HPAI getControlEndpoint()
	{
		return endpt;
	}

	/**
	 * Returns the device description information block of the server contained in the
	 * response.
	 * <p>
	 * 
	 * @return a device DIB
	 */
	public final DeviceDIB getDevice()
	{
		return desc.getDevice();
	}

	/**
	 * Returns the supported service families description information block of the server
	 * contained in the response.
	 * <p>
	 * 
	 * @return a DIB with the supported service families
	 */
	public final SuppFamiliesDIB getServiceFamilies()
	{
		return desc.getServiceFamilies();
	}

	/* (non-Javadoc)
	 * @see tuwien.auto.calimero.knxnetip.servicetype.ServiceType#getStructLength()
	 */
	short getStructLength()
	{
		return (short) (endpt.getStructLength() + desc.getDevice().getStructLength() +
			desc.getServiceFamilies().getStructLength());
	}

	/* (non-Javadoc)
	 * @see tuwien.auto.calimero.knxnetip.servicetype.ServiceType#toByteArray
	 *      (java.io.ByteArrayOutputStream)
	 */
	byte[] toByteArray(ByteArrayOutputStream os)
	{
		byte[] buf = desc.getDevice().toByteArray();
		os.write(buf, 0, buf.length);
		buf = desc.getServiceFamilies().toByteArray();
		os.write(buf, 0, buf.length);
		return os.toByteArray();
	}
}