textdocumentmessageelement.java

JXTA&#8482 is a set of open, generalized peer-to-peer (P2P) protocols that allow any networked devi

/*
 * Copyright (c) 2001-2007 Sun Microsystems, Inc.  All rights reserved.
 *  
 *  The Sun Project JXTA(TM) Software License
 *  
 *  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 Sun Microsystems, Inc. for JXTA(TM) technology." 
 *     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.
 *  
 *  JXTA is a registered trademark of Sun Microsystems, Inc. in the United 
 *  States and other countries.
 *  
 *  Please see the license information page at :
 *  <http://www.jxta.org/project/www/license.html> for instructions on use of 
 *  the license in source files.
 *  
 *  ====================================================================
 *  
 *  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. 
 */
package net.jxta.endpoint;


import net.jxta.document.MimeMediaType;
import net.jxta.document.TextDocument;
import net.jxta.logging.Logging;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
import java.lang.ref.SoftReference;
import java.util.logging.Level;
import java.util.logging.Logger;


/**
 * A Message Element using JXTA TextDocument for the element data.
 */
public class TextDocumentMessageElement extends TextMessageElement {

    /**
     * Log4J Logger
     */
    private static final Logger LOG = Logger.getLogger(TextDocumentMessageElement.class.getName());

    /**
     * The data for this element.
     */
    protected TextDocument doc;

    /**
     * Create a new Message Element from the provided Document.
     *
     * @param name Name of the Element. May be the empty string ("") or null if
     *             the Element is not named.
     * @param doc  A Document containing the contents of this element.
     * @param sig  optional message digest/digital signature elemnent. If
     *             no signature is to be specified, pass null.
     */
    public TextDocumentMessageElement(String name, TextDocument doc, MessageElement sig) {
        super(name, doc.getMimeType(), sig);

        this.doc = doc;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean equals(Object target) {
        if (this == target) {
            return true;
        }

        if (target instanceof MessageElement) {
            if (!super.equals(target)) {
                return false;
            }

            if (target instanceof TextMessageElement) {
                // have to do a slow char by char comparison. Still better than the stream since it saves encoding.
                // XXX 20020615 [e-mail] the performance of this could be much improved.

                TextMessageElement likeMe = (TextMessageElement) target;

                try {
                    Reader myReader = getReader();
                    Reader itsReader = likeMe.getReader();

                    int mine;
                    int its;

                    do {
                        mine = myReader.read();
                        its = itsReader.read();

                        if (mine != its) {
                            return false;
                        }       // content didn't match

                    } while ((-1 != mine) && (-1 != its));

                    return ((-1 == mine) && (-1 == its)); // end at the same time?
                } catch (IOException fatal) {
                    throw new IllegalStateException("MessageElements could not be compared." + fatal);
                }
            } else {
                // have to do a slow stream comparison.
                // XXX 20020615 [e-mail] the performance of this could be much improved.

                MessageElement likeMe = (MessageElement) target;

                try {
                    InputStream myStream = getStream();
                    InputStream itsStream = likeMe.getStream();

                    int mine;
                    int its;

                    do {
                        mine = myStream.read();
                        its = itsStream.read();

                        if (mine != its) {
                            return false;
                        }       // content didn't match

                    } while ((-1 != mine) && (-1 != its));

                    return ((-1 == mine) && (-1 == its)); // end at the same time?
                } catch (IOException fatal) {
                    throw new IllegalStateException("MessageElements could not be compared." + fatal);
                }
            }
        }

        return false; // not a new message element
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int hashCode() {
        int result = super.hashCode() * 6037 + // a prime
                toString().hashCode();

        return result;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public synchronized String toString() {
        String result;

        if (null != cachedToString) {
            result = cachedToString.get();

            if (null != result) {
                return result;
            }
        }

        if (Logging.SHOW_FINER && LOG.isLoggable(Level.FINER)) {
            LOG.finer("creating toString of " + getClass().getName() + "@" + super.hashCode());
        }

        result = doc.toString();
        cachedToString = new SoftReference<String>(result);
        return result;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public MimeMediaType getMimeType() {
        return doc.getMimeType();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getFileExtension() {
        return doc.getFileExtension();
    }

    /**
     * {@inheritDoc}
     */
    public InputStream getStream() throws IOException {
        byte[] sending = getBytes(false);

        return new ByteArrayInputStream(sending);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void sendToStream(OutputStream sendTo) throws IOException {

        byte[] sending = getBytes(false);

        sendTo.write(sending, 0, sending.length);
    }

    /**
     * {@inheritDoc}
     */
    public Reader getReader() throws IOException {

        return doc.getReader();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void sendToWriter(Writer sendTo) throws IOException {
        doc.sendToWriter(sendTo);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public byte[] getBytes(boolean copy) {
        byte[] result;

        if (null != cachedGetBytes) {
            result = cachedGetBytes.get();

            if (null != result) {
                if (copy) {
                    byte[] theCopy = new byte[result.length];

                    System.arraycopy(theCopy, 0, result, 0, result.length);
                } else {
                    return result;
                }
            }
        }

        if (Logging.SHOW_FINER && LOG.isLoggable(Level.FINER)) {
            LOG.finer("creating getBytes of " + getClass().getName() + '@' + Integer.toHexString(hashCode()));
        }

        String charset = type.getParameter("charset");

        if (null == charset) {
            result = toString().getBytes();
        } else {
            try {
                result = toString().getBytes(charset);
            } catch (UnsupportedEncodingException caught) {
                if (Logging.SHOW_WARNING && LOG.isLoggable(Level.WARNING)) {
                    LOG.log(Level.WARNING, "MessageElement Data could not be generated", caught);
                }
                throw new IllegalStateException("MessageElement Data could not be generated due to " + caught.getMessage());
            }
        }

        // if this is supposed to be a shared buffer then we can cache it.
        if (!copy) {
            cachedGetBytes = new SoftReference<byte[]>(result);
        }

        return result;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public long getCharLength() {
        return toString().length();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public char[] getChars(boolean copy) {
        char[] result;

        if (null != cachedGetChars) {
            result = cachedGetChars.get();

            if (null != result) {
                if (copy) {
                    char[] theCopy = new char[result.length];

                    System.arraycopy(theCopy, 0, result, 0, result.length);
                } else {
                    return result;
                }
            }
        }

        if (Logging.SHOW_FINER && LOG.isLoggable(Level.FINER)) {
            LOG.finer("creating getChars of " + getClass().getName() + '@' + Integer.toHexString(hashCode()));
        }

        String asString = toString();

        result = asString.toCharArray();

        // if this is supposed to be a shared buffer then we can cache it.
        if (!copy) {
            cachedGetChars = new SoftReference<char[]>(result);
        }

        return result;
    }
}