Package org.apache.pdfbox.io

Class PushBackInputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    Direct Known Subclasses:
    ByteArrayPushBackInputStream
    public class PushBackInputStream
extends java.io.PushbackInputStream
    A simple subclass that adds a few convience methods.
    Version:
    $Revision: 1.6 $
    Author:
    Ben Litchfield

    • Field Summary

      • Fields inherited from class java.io.PushbackInputStream

        buf, pos

      • Fields inherited from class java.io.FilterInputStream

        in

    • Constructor Summary

      Constructors 
      Constructor Description
      PushBackInputStream​(java.io.InputStream input, int size)
      Constructor.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void fillBuffer()
      This is a method used to fix PDFBox issue 974661, the PDF parsing code needs to know if there is at least x amount of data left in the stream, but the available() method returns how much data will be available without blocking.
      long getOffset()
      Returns the current byte offset in the file.
      boolean isEOF()
      A simple test to see if we are at the end of the stream.
      int peek()
      This will peek at the next byte.
      int read()
      int read​(byte[] b)
      int read​(byte[] b, int off, int len)
      byte[] readFully​(int length)
      Reads a given number of bytes from the underlying stream.
      void seek​(long newOffset)
      Allows to seek to another position within stream in case the underlying stream implements RandomAccessRead.
      void unread​(byte[] b)
      void unread​(byte[] b, int off, int len)
      void unread​(int b)

      • Methods inherited from class java.io.PushbackInputStream

        available, close, mark, markSupported, reset, skip

      • Methods inherited from class java.io.InputStream

        nullInputStream, readAllBytes, readNBytes, readNBytes, transferTo

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • PushBackInputStream

        public PushBackInputStream​(java.io.InputStream input,
                           int size)
                    throws java.io.IOException
        Constructor.
        Parameters:
        input - The input stream.
        size - The size of the push back buffer.
        Throws:
        java.io.IOException - If there is an error with the stream.

    • Method Detail

      • peek

        public int peek()
         throws java.io.IOException
        This will peek at the next byte.
        Returns:
        The next byte on the stream, leaving it as available to read.
        Throws:
        java.io.IOException - If there is an error reading the next byte.

      • getOffset

        public long getOffset()
        Returns the current byte offset in the file.
        Returns:
        the int byte offset

      • read

        public int read()
         throws java.io.IOException
        Overrides:
        read in class java.io.PushbackInputStream
        Throws:
        java.io.IOException

      • read

        public int read​(byte[] b)
         throws java.io.IOException
        Overrides:
        read in class java.io.FilterInputStream
        Throws:
        java.io.IOException

      • read

        public int read​(byte[] b,
                int off,
                int len)
         throws java.io.IOException
        Overrides:
        read in class java.io.PushbackInputStream
        Throws:
        java.io.IOException

      • unread

        public void unread​(int b)
            throws java.io.IOException
        Overrides:
        unread in class java.io.PushbackInputStream
        Throws:
        java.io.IOException

      • unread

        public void unread​(byte[] b)
            throws java.io.IOException
        Overrides:
        unread in class java.io.PushbackInputStream
        Throws:
        java.io.IOException

      • unread

        public void unread​(byte[] b,
                   int off,
                   int len)
            throws java.io.IOException
        Overrides:
        unread in class java.io.PushbackInputStream
        Throws:
        java.io.IOException

      • isEOF

        public boolean isEOF()
              throws java.io.IOException
        A simple test to see if we are at the end of the stream.
        Returns:
        true if we are at the end of the stream.
        Throws:
        java.io.IOException - If there is an error reading the next byte.

      • fillBuffer

        public void fillBuffer()
                throws java.io.IOException
        This is a method used to fix PDFBox issue 974661, the PDF parsing code needs to know if there is at least x amount of data left in the stream, but the available() method returns how much data will be available without blocking. PDFBox is willing to block to read the data, so we will first fill the internal buffer.
        Throws:
        java.io.IOException - If there is an error filling the buffer.

      • readFully

        public byte[] readFully​(int length)
                 throws java.io.IOException
        Reads a given number of bytes from the underlying stream.
        Parameters:
        length - the number of bytes to be read
        Returns:
        a byte array containing the bytes just read
        Throws:
        java.io.IOException - if an I/O error occurs while reading data

      • seek

        public void seek​(long newOffset)
          throws java.io.IOException
        Allows to seek to another position within stream in case the underlying stream implements RandomAccessRead. Otherwise an IOException is thrown. Pushback buffer is cleared before seek operation by skipping over all bytes of buffer.
        Parameters:
        newOffset - new position within stream from which to read next
        Throws:
        java.io.IOException - if underlying stream does not implement RandomAccessRead or seek operation on underlying stream was not successful