Package org.apache.tika.io

Class TailStream

java.lang.Object
java.io.InputStream
java.io.FilterInputStream
org.apache.tika.io.TailStream
Record Components:
in - the underlying input stream
tailSize - the size of the tail buffer
All Implemented Interfaces:
Closeable, AutoCloseable
public class TailStream extends FilterInputStream

A specialized input stream implementation which records the last portion read from an underlying stream.

This stream implementation is useful to deal with information which is known to be located at the end of a stream (e.g. ID3 v1 tags). While reading bytes from the underlying stream, a given number of bytes is kept in an internal buffer. This buffer can then be queried after the whole stream was read. It contains the last bytes read from the original input stream.

  • Field Summary

    Fields inherited from class java.io.FilterInputStream

    in

  • Constructor Summary

    Constructors
    Constructor
    Description
    TailStream(InputStream in, int size)
    Creates a new instance of TailStream.

  • Method Summary

    Modifier and Type
    Method
    Description
    byte[]
    getTail()
    Returns an array with the last data read from the underlying stream.
    void
    mark(int limit)
    This implementation saves the internal state including the content of the tail buffer so that it can be restored when ''reset()'' is called later.
    int
    read()
    This implementation adds the read byte to the internal tail buffer.
    int
    read(byte[] buf)
    This implementation delegates to the underlying stream and then adds the correct portion of the read buffer to the internal tail buffer.
    int
    read(byte[] buf, int ofs, int length)
    This implementation delegates to the underlying stream and then adds the correct portion of the read buffer to the internal tail buffer.
    void
    reset()
    This implementation restores this stream's state to the state when ''mark()'' was called the last time.
    long
    skip(long n)
    This implementation delegates to the read() method to ensure that the tail buffer is also filled if data is skipped.

    Methods inherited from class java.io.FilterInputStream

    available, close, markSupported

    Methods inherited from class java.io.InputStream

    nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • TailStream

      public TailStream(InputStream in, int size)
      Creates a new instance of TailStream.
      Parameters:
      in - the underlying input stream
      size - the size of the tail buffer

  • Method Details

    • read

      public int read() throws IOException
      This implementation adds the read byte to the internal tail buffer.
      Overrides:
      read in class FilterInputStream
      Throws:
      IOException

    • read

      public int read(byte[] buf) throws IOException
      This implementation delegates to the underlying stream and then adds the correct portion of the read buffer to the internal tail buffer.
      Overrides:
      read in class FilterInputStream
      Throws:
      IOException

    • read

      public int read(byte[] buf, int ofs, int length) throws IOException
      This implementation delegates to the underlying stream and then adds the correct portion of the read buffer to the internal tail buffer.
      Overrides:
      read in class FilterInputStream
      Throws:
      IOException

    • skip

      public long skip(long n) throws IOException
      This implementation delegates to the read() method to ensure that the tail buffer is also filled if data is skipped.
      Overrides:
      skip in class FilterInputStream
      Throws:
      IOException

    • mark

      public void mark(int limit)
      This implementation saves the internal state including the content of the tail buffer so that it can be restored when ''reset()'' is called later.
      Overrides:
      mark in class FilterInputStream

    • reset

      public void reset()
      This implementation restores this stream's state to the state when ''mark()'' was called the last time. If ''mark()'' has not been called before, this method has no effect.
      Overrides:
      reset in class FilterInputStream

    • getTail

      public byte[] getTail()
      Returns an array with the last data read from the underlying stream. If the underlying stream contained more data than the ''tailSize'' constructor argument, the returned array has a length of ''tailSize''. Otherwise, its length equals the number of bytes read.
      Returns:
      an array with the last data read from the underlying stream