markprohibitedfilterstream.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: MarkProhibitedFilterStream.java,v 1.3 2003/03/21 00:41:56 bondolo Exp $
 */

package net.jxta.util;

import java.io.FilterInputStream;
import java.io.InputStream;

import java.io.IOException;

/**
 *  Implements a filter which disables the mark() feature of an input stream.
 *  Useful for when the stream is shared.
 **/
public class MarkProhibitedFilterStream extends FilterInputStream {
    
    /**
     * Creates a new instance of MarkProhibitedFilterStream
     *
     *    @param  in  the stream which will be limited.
     */
    public MarkProhibitedFilterStream(InputStream in) {
        super( in );
    }
    
    /** 
     *	{@inheritDoc}
     *
     *	<p/>This method does nothing.
     **/
    public void mark(int readlimit) {
    }
    
    /** 
     *	{@inheritDoc}
     *
     *	<p/>This implementation always throws IOException since mark is not
     *	supported.
     */
    public void reset() throws IOException {
        throw new IOException( "reset() not supported" );
    }
    
    /** 
     *	{@inheritDoc}
     *
     * <p/>This method simply returns false.
     **/
    public boolean markSupported() {
        return false;
    }
    
}