/************************************************************************ * * $Id: StringMessageElement.java,v 1.16 2005/08/08 19:59:05 bondolo Exp $ * * 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. *********************************************************************************/package net.jxta.endpoint;import java.io.ByteArrayInputStream;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.io.Reader;import java.io.StringReader;import java.io.Writer;import java.nio.ByteBuffer;import java.nio.CharBuffer;import java.nio.charset.Charset;import java.nio.charset.CharsetEncoder;import java.nio.charset.CoderResult;import java.nio.charset.CodingErrorAction;import java.lang.ref.SoftReference;import java.io.UnsupportedEncodingException;import java.io.IOException;import org.apache.log4j.Level;import org.apache.log4j.Logger;import net.jxta.document.MimeMediaType;/** *  A Message Element using character strings for the element data. * **/public class StringMessageElement extends TextMessageElement {    /**     *  Log4J Logger     **/    private final static transient Logger LOG = Logger.getLogger( StringMessageElement.class.getName() );        private static final MimeMediaType DEFAULT_TEXT_ENCODING;        static {        // There doesn't seem to be a way to do this directly. The goal is to get        // the canonical name of the encoding being used. Since ByteArrayInputStream        // does not copy the data, this operation is relatively cheap if a little        // circuitous.        InputStreamReader getEncoding = new InputStreamReader( new ByteArrayInputStream( new byte [0] ) );                String encoding = getEncoding.getEncoding();                  /**            bondolo 20040904 For J2SE 5.0 :                     String encoding = java.nio.charset.Charset.defaultCharset().name();                 **/      DEFAULT_TEXT_ENCODING = new MimeMediaType( MimeMediaType.TEXT_DEFAULTENCODING, "charset=\"" + encoding + "\"", true ).intern();    }        /**     *  The data for this Message Element.     **/    protected String data;        /**     *  Returns an appropriate mime type for the given encoding name. The     *  mimetype will contain the canonical name of the encoding.     *     *  @param encoding name of the desired encoding.     *  @return the mime type.     **/    private static MimeMediaType makeMimeType( String encoding ) throws UnsupportedEncodingException {         InputStreamReader getEncoding = new InputStreamReader( new ByteArrayInputStream( new byte [0] ), encoding );                String canonicalName = getEncoding.getEncoding();               return new MimeMediaType( MimeMediaType.TEXT_DEFAULTENCODING, "charset=\"" + canonicalName + "\"", true ).intern();    }        /**     *  Create a new Message Element from the provided String. The String will     *  be encoded for transmission using UTF-8.     *     *  @param name Name of the Element. May be the empty string ("") or null if     *  the Element is not named.     *  @param value A String containing the contents of this element.     *  @param sig Message digest/digital signature element. If no signature is     *  to be specified, pass <code>null</code>.     *     *  @throws IllegalArgumentException if <code>value</code> is     *  <code>null</code>.     **/    public StringMessageElement(String name, String value, MessageElement sig) {        super( name, MimeMediaType.TEXTUTF8, sig );                if( null == value ) {            throw new IllegalArgumentException( "value must be non-null" );        }                data = value;    }        /**     *  Create a new Message Element from the provided String. The string will     *  be encoded for transmission using specified character encoding.     *     *  @param name Name of the MessageElement. May be the empty string ("") or     *  <code>null</code> if the MessageElement is not named.     *  @param value A String containing the contents of this element.     *  @param encoding Name of the character encoding to use. If     *  <code>null</code> then the system default charcter encoding will be     *  used. (Using the system default charcter encoding should be used with     *  extreme caution).     *  @param sig Message digest/digital signature element. If no signature is     *  to be specified, pass <code>null</code>.     *     *  @throws IllegalArgumentException if <code>value</code> is     *  <code>null</code>.     *  @throws UnsupportedEncodingException if the requested encoding is not     *  supported.     **/    public StringMessageElement( String name, String value, String encoding, MessageElement sig ) throws UnsupportedEncodingException {        super( name, (null == encoding) ? DEFAULT_TEXT_ENCODING : makeMimeType(encoding), sig );                if( null == value ) {            throw new IllegalArgumentException( "value must be non-null" );        }                data = value;    }        /**     *  {@inheritDoc}     **/    public boolean equals( Object target ) {        if( this == target ) {            return true;        }                if( target instanceof MessageElement ) {            if( !super.equals(target) )                return false;                        if( target instanceof StringMessageElement ) {                StringMessageElement likeMe = (StringMessageElement) target;                                return data.equals( likeMe.data ); // same chars?            } else if ( target instanceof TextMessageElement) {                // have to do a slow char by char comparison. Still better than the stream since it saves encoding.                // XXX 20020615 bondolo@jxta.org 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 ) {                    IllegalStateException failure = new IllegalStateException( "MessageElements could not be compared." );                    failure.initCause( fatal );                    throw failure;                }            }            else {                // have to do a slow stream comparison.                // XXX 20020615 bondolo@jxta.org 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 ) {                    IllegalStateException failure = new IllegalStateException( "MessageElements could not be compared." );                    failure.initCause( fatal );                    throw failure;                }            }        }                return false; // not a new message element    }        /**     *  {@inheritDoc}     **/    public int hashCode() {        int result = super.hashCode() * 6037 + // a prime        data.hashCode();                return result;