http://commons.apache.org/proper/commons-vfs/: Apache Commons VFS is a Virtual File System library. (The Apache Software Foundation)
  • Rami Ojares
  • Anthony Goubard
  • Christopher Ottley
  • Dave Marion
  • Scott Bjerstedt
  • Jose Juan Montiel
  • Otto Fowler
  • Adam Murdoch ()
  • James Strachan (SpiritSoft, Inc.)
  • Mario Ivankovits (OPS EDV Gmbh)
  • Rahul Akolkar (The Apache Software Foundation)
  • James Carman (The Apache Software Foundation)
  • Ralph Goers (Intuit)
  • Joerg Schaible
  • Gary D. Gregory
  • Bernd Eckenfels 
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.vfs2;

import java.io.Closeable;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.InputStream;


Provides random access over content.

/**
 * Provides random access over content.
 */
public interface RandomAccessContent extends DataOutput, DataInput, Closeable {

    
Closes this random access file stream and releases any system resources associated with the stream.


A closed random access file cannot perform input or output operations and cannot be reopened.




If this file has an associated channel then the channel is closed as well.



Throws:
  • IOException – if an I/O error occurs.
/**
     * Closes this random access file stream and releases any system resources associated with the stream.
     * <p>
     * A closed random access file cannot perform input or output operations and cannot be reopened.
     * </p>
     * <p>
     * If this file has an associated channel then the channel is closed as well.
     * </p>
     *
     * @throws IOException if an I/O error occurs.
     */
    @Override
    void close() throws IOException;

    
Returns the current offset in this file.

Throws:
Returns:the offset from the beginning of the file, in bytes, at which the next read or write occurs.
/**
     * Returns the current offset in this file.
     *
     * @return the offset from the beginning of the file, in bytes, at which the next read or write occurs.
     * @throws IOException if an I/O error occurs.
     */
    long getFilePointer() throws IOException;

    
Get the input stream.


Notice: If you use seek(long) you have to re-get the InputStream



Throws:
Returns:the InputStream.
/**
     * Get the input stream.
     * <p>
     * <b>Notice: If you use {@link #seek(long)} you have to re-get the InputStream</b>
     * </p>
     *
     * @return the InputStream.
     * @throws IOException if an I/O error occurs.
     */
    InputStream getInputStream() throws IOException;

    
Returns the length of this file.

Throws:
Returns:the length of this file, measured in bytes.
/**
     * Returns the length of this file.
     *
     * @return the length of this file, measured in bytes.
     * @throws IOException if an I/O error occurs.
     */
    long length() throws IOException;

    
Sets the file-pointer offset, measured from the beginning of this file, at which the next read or write occurs.


The offset may be set beyond the end of the file. Setting the offset beyond the end of the file does not change
the file length. The file length will change only by writing after the offset has been set beyond the end of the
file.




Notice: If you use getInputStream() you have to re-get the InputStream after calling seek(long)



Params:
  • pos – the offset position, measured in bytes from the beginning of the file, at which to set the file
           pointer.
Throws:
  • IOException – if pos is less than 0 or if an I/O error occurs.
/**
     * Sets the file-pointer offset, measured from the beginning of this file, at which the next read or write occurs.
     * <p>
     * The offset may be set beyond the end of the file. Setting the offset beyond the end of the file does not change
     * the file length. The file length will change only by writing after the offset has been set beyond the end of the
     * file.
     * </p>
     * <p>
     * <b>Notice: If you use {@link #getInputStream()} you have to re-get the InputStream after calling
     * {@link #seek(long)}</b>
     * </p>
     *
     * @param pos the offset position, measured in bytes from the beginning of the file, at which to set the file
     *            pointer.
     * @throws IOException if {@code pos} is less than {@code 0} or if an I/O error occurs.
     */
    void seek(long pos) throws IOException;

    
Sets the length of this content.

 If the the newLength argument is smaller than length(), the content is truncated. 


 If the the newLength argument is greater than length(), the content grows with undefined data. 


Params:
  • newLength – The desired content length
Throws:
Since:2.1
/**
     * Sets the length of this content.
     *
     * <p>
     * If the the {@code newLength} argument is smaller than {@link #length()}, the content is truncated.
     * </p>
     *
     * <p>
     * If the the {@code newLength} argument is greater than {@link #length()}, the content grows with undefined data.
     * </p>
     *
     * @param newLength The desired content length
     * @throws IOException If an I/O error occurs
     * @since 2.1
     */
    void setLength(long newLength) throws IOException;

}