Package org.apache.pdfbox.io

Class NonSeekableRandomAccessReadInputStream

java.lang.Object
org.apache.pdfbox.io.NonSeekableRandomAccessReadInputStream
All Implemented Interfaces:
Closeable, AutoCloseable, RandomAccessRead
public class NonSeekableRandomAccessReadInputStream extends Object implements RandomAccessRead
An implementation of the RandomAccessRead interface using an InputStream as source. It is optimized for a minimal memory footprint by using a small buffer to read from the input stream instead of copying the whole input stream to memory. This reduces the random access read abilities, so that peek/rewind operations are limited to the data within the buffer. This class is meant to be used by consumers which process the data more or less in a serial manner and therefore don't need full random access.

  • Field Details

    • LOG

      private static final org.apache.commons.logging.Log LOG

    • position

      protected long position

    • currentBufferPointer

      protected int currentBufferPointer

    • size

      protected long size

    • is

      private final InputStream is

    • BUFFER_SIZE

      private static final int BUFFER_SIZE
      See Also:

    • CURRENT

      private static final int CURRENT
      See Also:

    • LAST

      private static final int LAST
      See Also:

    • NEXT

      private static final int NEXT
      See Also:

    • buffers

      private final byte[][] buffers

    • bufferBytes

      private final int[] bufferBytes

    • isClosed

      private boolean isClosed

    • isEOF

      private boolean isEOF

  • Constructor Details

    • NonSeekableRandomAccessReadInputStream

      public NonSeekableRandomAccessReadInputStream(InputStream inputStream)
      Default constructor.

  • Method Details

    • close

      public void close() throws IOException
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Throws:
      IOException

    • seek

      public void seek(long position) throws IOException
      Seek to a position in the data.
      Specified by:
      seek in interface RandomAccessRead
      Parameters:
      position - The position to seek to.
      Throws:
      IOException - If there is an error while seeking.

    • skip

      public void skip(int length) throws IOException
      Description copied from interface: RandomAccessRead
      Skips a given number of bytes.
      Specified by:
      skip in interface RandomAccessRead
      Parameters:
      length - the number of bytes to be skipped
      Throws:
      IOException - if an I/O error occurs while reading data

    • getPosition

      public long getPosition() throws IOException
      Returns offset of next byte to be returned by a read method.
      Specified by:
      getPosition in interface RandomAccessRead
      Returns:
      offset of next byte which will be returned with next RandomAccessRead.read() (if no more bytes are left it returns a value >= length of source)
      Throws:
      IOException - If there was an error while getting the current position

    • read

      public int read() throws IOException
      Read a single byte of data.
      Specified by:
      read in interface RandomAccessRead
      Returns:
      The byte of data that is being read.
      Throws:
      IOException - If there is an error while reading the data.

    • read

      public int read(byte[] b, int offset, int length) throws IOException
      Read a buffer of data.
      Specified by:
      read in interface RandomAccessRead
      Parameters:
      b - The buffer to write the data to.
      offset - Offset into the buffer to start writing.
      length - The amount of data to attempt to read.
      Returns:
      The number of bytes that were actually read.
      Throws:
      IOException - If there was an error while reading the data.

    • switchBuffers

      private void switchBuffers(int firstBuffer, int secondBuffer)

    • fetch

      private boolean fetch() throws IOException
      Throws:
      IOException

    • length

      public long length() throws IOException
      The total number of bytes that are available.
      Specified by:
      length in interface RandomAccessRead
      Returns:
      The number of bytes available.
      Throws:
      IOException - If there is an IO error while determining the length of the data stream.

    • rewind

      public void rewind(int bytes) throws IOException
      Description copied from interface: RandomAccessRead
      Seek backwards the given number of bytes.
      Specified by:
      rewind in interface RandomAccessRead
      Parameters:
      bytes - the number of bytes to be seeked backwards
      Throws:
      IOException - If there is an error while seeking

    • checkClosed

      protected void checkClosed() throws IOException
      Ensure that the RandomAccessBuffer is not closed
      Throws:
      IOException - If RandomAccessBuffer already closed

    • isClosed

      public boolean isClosed()
      Returns true if this source has been closed.
      Specified by:
      isClosed in interface RandomAccessRead
      Returns:
      true if the source has been closed

    • isEOF

      public boolean isEOF() throws IOException
      A simple test to see if we are at the end of the data.
      Specified by:
      isEOF in interface RandomAccessRead
      Returns:
      true if we are at the end of the data.
      Throws:
      IOException - If there is an error reading the next byte.

    • createView

      public RandomAccessReadView createView(long startPosition, long streamLength) throws IOException
      Description copied from interface: RandomAccessRead
      Creates a random access read view starting at the given position with the given length.
      Specified by:
      createView in interface RandomAccessRead
      Parameters:
      startPosition - start position within the underlying random access read
      streamLength - stream length
      Returns:
      the random access read view
      Throws:
      IOException - if something went wrong when creating the view for the RandomAccessRead