piperesolvermsg.java

来自「jxme的一些相关程序,主要是手机上程序开发以及手机和计算机通信的一些程序资料,」· Java 代码 · 共 335 行

/*
 * Copyright (c) 2002 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: PipeResolverMsg.java,v 1.3 2002/06/18 20:46:00 hamada Exp $
 */

package net.jxta.impl.protocol;

import java.io.InputStream;
import java.io.StringWriter;
import java.io.StringReader;
import java.io.Writer;
import java.net.URL;
import java.util.Hashtable;
import java.util.Enumeration;

import java.io.IOException;
import java.net.MalformedURLException;
import java.net.UnknownServiceException;

import org.apache.log4j.Category;
import org.apache.log4j.Priority;

import net.jxta.document.AdvertisementFactory;
import net.jxta.document.Element;
import net.jxta.document.TextElement;
import net.jxta.document.MimeMediaType;
import net.jxta.document.Document;
import net.jxta.document.StructuredTextDocument;
import net.jxta.document.StructuredDocumentFactory;
import net.jxta.document.StructuredDocumentUtils;
import net.jxta.id.ID;
import net.jxta.id.IDFactory;
import net.jxta.peer.PeerID;
import net.jxta.pipe.PipeID;
import net.jxta.protocol.PeerAdvertisement;
import net.jxta.protocol.PipeResolverMessage;

/**
 * This class implements net.jxta.protocol.PipeResolverMessage.
 *
 *  It implements the message with the following schema.
 *
 * <pre><tt>
 * &lt;xs:complexType name="PipeResolver">
 * &lt;!-- MsgType should be an enumeration choice of "Query" and "Answer" -->
 * &lt;xs:element name="MsgType" type="xs:string"/>
 * &lt;xs:element name="PipeId" type="JXTAID"/>
 * &lt;xs:element name="Type" type="xs:string"/>
 * &lt;xs:element name="Peer" type="JXTAID" minOccurs="0" maxOccurs="unbounded"/>
 *
 * &lt;!-- following are used in the query -->
 * &lt;xs:element name="Cached" type="xs:boolean" default="true" minOccurs="0"/>
 *
 * &lt;!-- following are used in the answer -->
 * &lt;xs:element name="Found" type="xs:boolean" default="true" minOccurs="0"/>
 * &lt;!-- This should refer to a peer adv, but is instead a whole doc -->
 * &lt;xs:element name="PeerAdv" type="xs:string" minOccurs="0"/>
 * &lt;/xs:complexType>
 * </tt></pre>
 *
 */
public class PipeResolverMsg extends PipeResolverMessage {
  /**
   *  Log4J categorgy
   **/
  private static final Category LOG = Category.getInstance( PipeResolverMsg.class.getName());
  
  private final static String MsgTypeTag       = "MsgType";
  private final static String PipeIdTag        = "PipeId";
  private final static String PipeTypeTag      = "Type";
  private final static String PeerIdTag        = "Peer";
  private final static String CachedTag        = "Cached";
  private final static String PeerAdvTag       = "PeerAdv";
  private final static String FoundTag         = "Found";
  private final static String QueryMsgType     = "Query";
  private final static String AnswerMsgType    = "Answer";
  
  public PipeResolverMsg() {
    super();
  }
  
  public PipeResolverMsg(Element root) {
    super();
    initialize( root );
  }
  
  /**
   *  Initializes the message from a document.
   **/
  public void initialize(Element root) {
    if( !TextElement.class.isInstance( root ) )
      throw new IllegalArgumentException( getClass().getName() + " only supports TextElement" );
    
    TextElement doc = (TextElement) root;
    
    String docName = doc.getName();
    
    if( !docName.equals(getMessageType()) )
      throw new IllegalArgumentException( "Could not construct : "
      + getClass().getName()
      + "from doc containing a "
      + docName );
    
    Enumeration enum = doc.getChildren();
    
    while (enum.hasMoreElements()) {
      TextElement elem = (TextElement) enum.nextElement();
      
      if (elem.getName().equals(MsgTypeTag)) {
        String msgtype = elem.getTextValue();
        if( msgtype.equals( QueryMsgType ) )
          setMsgType( PipeResolverMessage.MessageType.QUERY );
        else if ( msgtype.equals( AnswerMsgType ) )
          setMsgType( PipeResolverMessage.MessageType.ANSWER );
        else
          throw new IllegalArgumentException( "Unexpected Message Type in parsing." );
        continue;
      }
      if (elem.getName().equals(PipeIdTag)) {
        try {
          URL pipeID =  IDFactory.jxtaURL( elem.getTextValue() );
          setPipeID( IDFactory.fromURL( pipeID ) );
        } catch ( MalformedURLException badID ) {
          throw new IllegalArgumentException( "Bad pipe ID in message" );
        } catch ( UnknownServiceException badID ) {
          throw new IllegalArgumentException( "Unusable pipe ID in message" );
        }
        continue;
      }
      if (elem.getName().equals(PipeTypeTag)) {
        setPipeType( elem.getTextValue() );
        continue;
      }
      
      if (elem.getName().equals(PeerIdTag)) {
        try {
          URL peerID =  IDFactory.jxtaURL( elem.getTextValue() );
          addPeerID( IDFactory.fromURL( peerID ) );
        } catch ( MalformedURLException badID ) {
          throw new IllegalArgumentException( "Bad peer ID in message" );
        } catch ( UnknownServiceException badID ) {
          throw new IllegalArgumentException( "Unusable peerID in message" );
        }
        continue;
      }
      
      if (elem.getName().equals(FoundTag)) {
        setFound( Boolean.valueOf(elem.getTextValue()).booleanValue() );
        continue;
      }
      
      if (elem.getName().equals(CachedTag)) {
        setCachedLookup( Boolean.valueOf(elem.getTextValue()).booleanValue() );
        continue;
      }
      
      // let's check whether the responder sent us a adv
      if (elem.getName().equals(PeerAdvTag)) {
        String peerAdv = elem.getTextValue();
        try {
          setInputPeerAdv( (PeerAdvertisement) AdvertisementFactory.newAdvertisement(
          new MimeMediaType("text/xml"),
          new StringReader(peerAdv)) );
        } catch ( IOException caught ) {
          if (LOG.isEnabledFor(Priority.DEBUG))
            LOG.debug( "Malformed peer adv in message", caught );
          throw new IllegalArgumentException( "Malformed peer adv in message : " + caught.getMessage() );
        }
        continue;
      }
    }
    
    // Begin checking sanity!
    PipeResolverMessage.MessageType msgType = getMsgType();
    if ( null == msgType )
      throw new IllegalArgumentException( "Message type was never set!" );
    
    ID pipeID = getPipeID();
    if( (null == pipeID) || ID.nullID.equals(pipeID) || !(pipeID instanceof PipeID) )
      throw new IllegalArgumentException( "Input Pipe ID not set or invalid" );
    
    if ( null == getPipeType() )
      throw new IllegalArgumentException( "Pipe type was never set!" );
    
    //Query extra checks
    
    //Response extra checks
    if (  PipeResolverMessage.MessageType.ANSWER.equals( msgType ) ) {
      if( !getPeerIDs().hasMoreElements() ) {
        throw new IllegalArgumentException( "An answer without responses is invalid" );
      }
    }
  }
  
  /**
   *  Creates a document out of the message.
   *
   *  @param  encodeAs  The document representation format requested.
   *  @return the message as a document.
   **/
  public Document getDocument(MimeMediaType encodeAs) {
    StructuredTextDocument doc = (StructuredTextDocument)
    StructuredDocumentFactory.newStructuredDocument(encodeAs, getMessageType() );
    
    PipeResolverMessage.MessageType msgType = getMsgType();
    if ( null == msgType )
      throw new IllegalStateException( "Message type was never set!" );
    
    if ( null == getPipeType() )
      throw new IllegalStateException( "Pipe type was never set!" );
    
    ID pipeID = getPipeID();
    if( (null == pipeID) || ID.nullID.equals(pipeID) || !(pipeID instanceof PipeID) )
      throw new IllegalStateException( "Input Pipe ID not set or invalid" );
    
    Element e = null;
    if(  PipeResolverMessage.MessageType.QUERY.equals( msgType ) ) {
      e = doc.createElement(MsgTypeTag, QueryMsgType);
    } else if (  PipeResolverMessage.MessageType.ANSWER.equals( msgType ) ) {
      e = doc.createElement(MsgTypeTag, AnswerMsgType);
    } else {
      throw new IllegalStateException( "Unknown message type :" + msgType.toString() );
    }
    doc.appendChild(e);
    
    e = doc.createElement(PipeIdTag, pipeID.toString() );
    doc.appendChild(e);
    
    String pipeType = getPipeType();
    if( (null != pipeType) && (0 != pipeType.length()) ) {
      e = doc.createElement( PipeTypeTag, pipeType );
      doc.appendChild(e);
    }
    
    // Write the peer ids.
    Enumeration peers = getPeerIDs();
    while( peers.hasMoreElements() ) {
      ID aPeer = (ID) peers.nextElement();
      
      if( aPeer instanceof PeerID) {
        e = doc.createElement(PeerIdTag, aPeer.toString() );
        doc.appendChild(e);
      } else {
        if (LOG.isEnabledFor(Priority.DEBUG))
          LOG.debug( "Malformed peer id in list : " + aPeer );
      }
    }
    
    if(  PipeResolverMessage.MessageType.QUERY.equals( msgType ) ) {
      boolean cachedLookup = isCachedLookup();
      if ( cachedLookup ) {
        e = doc.createElement(CachedTag, Boolean.TRUE.toString() );
        doc.appendChild(e);
      }
    } else if (  PipeResolverMessage.MessageType.ANSWER.equals( msgType ) ) {
      e = doc.createElement(FoundTag, (isFound() ? Boolean.TRUE : Boolean.FALSE).toString() );
      doc.appendChild(e);
      
      PeerAdvertisement peerAdv = getInputPeerAdv();
      
      if( null == peerAdv )
        throw new IllegalStateException( "Peer Advertisement must be present if respoinding with found" );
      
      Writer stringWriter = new StringWriter( );
      try {
        StructuredTextDocument asDoc = (StructuredTextDocument)
        peerAdv.getDocument( new MimeMediaType( "text/xml" ) );
        
        asDoc.sendToWriter( stringWriter );
        
        e = doc.createElement( PeerAdvTag, stringWriter.toString() );
        doc.appendChild(e);
      } catch ( IOException caught ) {
        throw new IllegalStateException( "Malformed Peer Advertisement :" + caught.getMessage() );
      }
    } else {
      throw new IllegalStateException( "Unknown message type :" + msgType.toString() );
    }
    
    return doc;
  }
  
}