resolversrdimsgimpl.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: ResolverSrdiMsgImpl.java,v 1.10 2004/09/28 02:00:31 hamada Exp $
 */
package net.jxta.impl.protocol;



import java.util.Enumeration;

import net.jxta.credential.Credential;
import net.jxta.document.*;
import net.jxta.membership.MembershipService;
import net.jxta.protocol.ResolverSrdiMsg;

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


/**
 * ResolverQuery provides the binding for the message to query other nodes
 */
public class ResolverSrdiMsgImpl extends ResolverSrdiMsg {

    private final static Logger LOG = Logger.getLogger(ResolverSrdiMsgImpl.class.getName());

    /**
     *  Description of the Field
     */
    public final static String handlernameTag = "HandlerName";

    /**
     *  Description of the Field
     */
    public final static String credentialTag = "jxta:Cred";

    /**
     *  Description of the Field
     */
    public final static String payloadTag = "Payload";

    /**
     *Constructor for the ResolverSrdiMsgImpl object
     */
    public ResolverSrdiMsgImpl() {}

    /**
     * Construct from a StructuredDocument
     *
     * @param  root  the underlying document
     * @param  membership membership service used to verify credentials
     */
    public ResolverSrdiMsgImpl(Element root, MembershipService membership) {
        if (!XMLElement.class.isInstance(root)) {
            throw new IllegalArgumentException(getClass().getName() + " only supports XLMElement");
        }

        XMLElement doc = (XMLElement) root;
        String doctype = doc.getName();
        if (!getMessageType().equals(doctype)) {
            throw new IllegalArgumentException("Could not construct : " + getClass().getName() + "from doc containing a " + doctype);
        }
        readIt(doc, membership);
    }

    /**
     * {@inheritDoc}
     */
    public ResolverSrdiMsgImpl(String handlerName, Credential cred, String payload) {

        setHandlerName(handlerName);
        setPayload(payload);
        setCredential(cred);
    }

    /**
     * return the string representaion of this doc
     *
     * @return    string representation of the message
     */
    public String toString() {

        StructuredTextDocument doc = (StructuredTextDocument) getDocument(MimeMediaType.XMLUTF8);
        return doc.toString();
    }

    /**
     * return a Document represetation of this object
     *
     * @param  asMimeType  type of message
     * @return             document
     */
    public Document getDocument(MimeMediaType asMimeType) {
        StructuredTextDocument adv = (StructuredTextDocument) StructuredDocumentFactory.newStructuredDocument(asMimeType, getMessageType());

        if (adv instanceof XMLElement) {
            ((XMLElement) adv).addAttribute("xmlns:jxta", "http://jxta.org");
        }

        Element e;
        e = adv.createElement(handlernameTag, getHandlerName());
        adv.appendChild(e);
        if (getCredential() != null) {
            try {
                StructuredDocumentUtils.copyElements(adv, adv, (getCredential()).getDocument(asMimeType));
            } catch (Exception ce) {
                if (LOG.isEnabledFor(Level.WARN)) {
                    LOG.warn("Got an Exception during credential creation ", ce);
                }
            }
        }
        e = adv.createElement(payloadTag, getPayload());
        adv.appendChild(e);
        return adv;
    }

    /**
     *  Parses an XML document into this object
     *
     * @param  doc  the underlying document
     * @param  membership  used to parse credentails if any
     */
    private void readIt(XMLElement doc, MembershipService membership) {
        Enumeration elements = doc.getChildren();

        while (elements.hasMoreElements()) {
            XMLElement elem = (XMLElement) elements.nextElement();

            if (elem.getName().equals(handlernameTag)) {
                setHandlerName(elem.getTextValue());
                continue;
            }
            // Set credential
            if (elem.getName().equals(credentialTag)) {
                Credential credential = null;

                if (elem.getTextValue() != null) {
                    try {
                        credential = membership.makeCredential(elem);
                        setCredential(credential);
                    } catch (Exception ce) {
                        if (LOG.isEnabledFor(Level.WARN)) {
                            LOG.warn("Credential creation failed", ce);
                        }
                    }
                }
                continue;
            }

            // Set payload
            if (elem.getName().equals(payloadTag)) {
                setPayload(elem.getTextValue());
                continue;
            }
        }
    }
}