Package org.apache.pdfbox.io

Class PushBackInputStream

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

  • Constructor Details

    • PushBackInputStream

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

  • Method Details

    • peek

      public int peek() throws IOException
      This will peek at the next byte.
      Returns:
      The next byte on the stream, leaving it as available to read.
      Throws:
      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 IOException
      Overrides:
      read in class PushbackInputStream
      Throws:
      IOException

    • read

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

    • read

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

    • unread

      public void unread(int b) throws IOException
      Overrides:
      unread in class PushbackInputStream
      Throws:
      IOException

    • unread

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

    • unread

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

    • isEOF

      public boolean isEOF() throws 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:
      IOException - If there is an error reading the next byte.

    • fillBuffer

      public void fillBuffer() throws 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:
      IOException - If there is an error filling the buffer.

    • readFully

      public byte[] readFully(int length) throws 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:
      IOException - if an I/O error occurs while reading data

    • seek

      public void seek(long newOffset) throws 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:
      IOException - if underlying stream does not implement RandomAccessRead or seek operation on underlying stream was not successful