discoveryquerymsg.java

jxta_src_2.41b jxta 2.41b 最新版源码 from www.jxta.org

/*
 *  Copyright (c) 2001 Sun Microsystems, Inc.  All rights
 *  reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *
 *  2. Redistributions in binary form must reproduce the above copyright
 *  notice, this list of conditions and the following disclaimer in
 *  the documentation and/or other materials provided with the
 *  distribution.
 *
 *  3. The end-user documentation included with the redistribution,
 *  if any, must include the following acknowledgment:
 *  "This product includes software developed by the
 *  Sun Microsystems, Inc. for Project JXTA."
 *  Alternately, this acknowledgment may appear in the software itself,
 *  if and wherever such third-party acknowledgments normally appear.
 *
 *  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
 *  not be used to endorse or promote products derived from this
 *  software without prior written permission. For written
 *  permission, please contact Project JXTA at http://www.jxta.org.
 *
 *  5. Products derived from this software may not be called "JXTA",
 *  nor may "JXTA" appear in their name, without prior written
 *  permission of Sun.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED.  IN NO EVENT SHALL SUN MICROSYSTEMS OR
 *  ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 *  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 *  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 *  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 *  SUCH DAMAGE.
 *  ====================================================================
 *
 *  This software consists of voluntary contributions made by many
 *  individuals on behalf of Project JXTA.  For more
 *  information on Project JXTA, please see
 *  <http://www.jxta.org/>.
 *
 *  This license is based on the BSD license adopted by the Apache Foundation.
 *
 *  $Id: DiscoveryQueryMsg.java,v 1.24 2004/05/19 01:27:08 bondolo Exp $
 */
package net.jxta.protocol;

import java.io.IOException;

import java.io.StringReader;
import net.jxta.discovery.DiscoveryService;

import net.jxta.document.AdvertisementFactory;
import net.jxta.document.Document;
import net.jxta.document.MimeMediaType;

import org.apache.log4j.Level;
import org.apache.log4j.Logger;

/**
 *  This class defines the Discovery Service message "Query". The default
 *  behavior of this abstract class is simply a place holder for the generic
 *  resolver query fields.
 *
 *@see    net.jxta.discovery.DiscoveryService
 *@see    net.jxta.protocol.DiscoveryResponseMsg
 */

public abstract class DiscoveryQueryMsg {
    
    private final static Logger LOG = Logger.getLogger(DiscoveryQueryMsg.class.getName());
    private PeerAdvertisement peerAdvertisement = null;

    /**
     *  default threshold to limit the number of responses from one peer
     */
    private int threshold = 10;

    /**
     *  FIXME 20030227 [e-mail] not a great default...
     */
    private int type = DiscoveryService.PEER;

    private String attr = null;
    private String value = null;

    /**
     *  returns the Attr value
     *
     *@return    String value of Attribute
     */
    public String getAttr() {
        return attr;
    }


    /**
     *  Get the response type
     *
     *@return    int PEER, or GROUP discovery type response
     */
    public int getDiscoveryType() {
        return type;
    }


    /**
     *  Write advertisement into a document. asMimeType is a mime media-type
     *  specification and provides the form of the document which is being
     *  requested. Two standard document forms are defined. "text/text" encodes
     *  the document in a form nice for printing out, and "text/xml" which
     *  provides an XML representation.
     *
     *@param  asMimeType  mime-type format requested
     *@return             Document representation of the document as an
     *      advertisement
     */
    public abstract Document getDocument(MimeMediaType asMimeType);


    /**
     *  returns the responding peer advertisement
     *
     *  @deprecated Peer Advertisement is available directly via
     * {@link #getPeerAdvertisement()}.
     *@return    String handlername name
     */
    public String getPeerAdv() {
        if( null != peerAdvertisement ) {
            return peerAdvertisement.toString();
        } else {
            return null;
        }
    }

    /**
     *
     *  @deprecated access peer advertisement directly
     **/
    public void setPeerAdv( String newAdv ) {
                try {
            peerAdvertisement = (PeerAdvertisement) AdvertisementFactory.newAdvertisement(MimeMediaType.XMLUTF8, new StringReader(newAdv));
        } catch( IOException failed ) {
            throw new IllegalArgumentException( "Bad Peer Avertisement" );
            }
        }
    
    /**
     *  returns the querying peer's advertisement
     *
     *@return peer advertisement of querier.
     */
    public PeerAdvertisement getPeerAdvertisement() {
        return peerAdvertisement;
    }

    /**
     *  returns the responding peer's advertisement
     *
     * @param newAdv peer advertisement of querier.
     */
    public void setPeerAdvertisement( PeerAdvertisement newAdv ) {
        peerAdvertisement = newAdv;
    }
    

    /**
     *  Get the Threshold for number of responses
     *
     *@return    int threshold
     */
    public int getThreshold() {
        return threshold;
    }


    /**
     *  returns the value of Attr
     *
     *@return    String
     */
    public String getValue() {
        return value;
    }


    /**
     *  set the attr
     *
     *@param  attr  attribute of the query
     */
    public void setAttr(String attr) {
        this.attr = attr;
    }


    /**
     *  set the Response type whether it's peer, or group discovery
     *
     *@param  type  type of discovery
     */
    public void setDiscoveryType(int type) {
        // FIXME 20030227 [e-mail] This should be value checked.
        this.type = type;
    }


    /**
     *  set the threshold
     *
     *@param  threshold  value to be set
     */
    public void setThreshold(int threshold) {
        this.threshold = threshold;
    }


    /**
     *  set the query
     *
     *@param  value  value of the attribute to query
     */
    public void setValue(String value) {
        this.value = value;
    }


    /**
     *  All messages have a type (in xml this is &#0033;doctype) which
     *  identifies the message
     *
     *@return    String "jxta:DiscoveryQuery"
     */
    public static String getAdvertisementType() {
        return "jxta:DiscoveryQuery";
    }
}