filedocument.java

jxta平台的开发包

/*
 * $Id: FileDocument.java,v 1.1 2006/06/02 18:31:57 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.document;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.OutputStream;

import java.io.IOException;

/**
 * This class presents a Document interface for a specific file on disk.
 */
public class FileDocument implements Document {
    
    private final static int BUFFER_SIZE = 4096;
    
    /**
     * File which backs this document.
     */
    private final File file;
    
    /**
     *  MIME media type of this document.
     **/
    private final MimeMediaType type;
    
    /**
     * Create a new File Document.
     **/
    public FileDocument( File file ) {
        this( file, StructuredDocumentFactory.getMimeTypeForFileExtension(getFileExtension( file )) );
    }
    
    /**
     * Create a new File Document.
     */
    public FileDocument( File file, MimeMediaType type ) {
        if (file.isDirectory()) {
            throw(new IllegalArgumentException("File cannot be a directory"));
        }
        
        if (!file.exists()) {
            throw(new IllegalArgumentException("File must exist"));
        }
        
        this.file = file;
        this.type = type.intern();
    }
    
    /**
     *  {@inheritDoc}
     *
     * <p/>Returns everything after the last '.' in the filename, or the
     * empty string if the file name does not contain a '.'.
     **/
    public String getFileExtension() {
        return getFileExtension( file );
    }
    
    /**
     * <p/>Returns everything after the last '.' in the filename, or the
     * empty string if the file name does not contain a '.'.
     **/
    private static String getFileExtension( File file ) {
        
        String fileName = file.getName();
        int idx = fileName.lastIndexOf('.');
        if (idx < 0 || idx == fileName.length()) {
            return "";
        } else {
            return fileName.substring(idx + 1);
        }
    }
    
    /**
     *  {@inheritDoc}
     **/
    public MimeMediaType getMimeType() {
        return type;
    }
    
    /**
     *  {@inheritDoc}
     **/
    public InputStream getStream() throws IOException {
        return new FileInputStream(file);
    }
    
    /**
     *  {@inheritDoc}
     **/
    public void sendToStream(OutputStream sink) throws IOException {
        InputStream source = getStream();
        int c;
        byte[] buf = new byte[BUFFER_SIZE];
        
        do {
            c=source.read(buf);
            
            if( -1 == c ) {
                break;
            }
            
            sink.write(buf,0,c);
        } while( true );
    }
}