Class JBIG2Document

java.lang.Object
org.apache.pdfbox.jbig2.JBIG2Document
class JBIG2Document extends Object
This class represents the document structure with its pages and global segments.

  • Field Details

    • FILE_HEADER_ID

      private int[] FILE_HEADER_ID
      ID string in file header, see ISO/IEC 14492:2001, D.4.1

    • pages

      private final Map<Integer, JBIG2Page> pages
      This map contains all pages of this document. The key is the number of the page.

    • fileHeaderLength

      private short fileHeaderLength
      The length of the file header if exists

    • organisationType

      private short organisationType
      According to D.4.2 - File header bit 0

      This flag contains information about the file organization:

      • 1 for sequential
      • 0 for random-access
      You can use the constants RANDOM and SEQUENTIAL.

    • RANDOM

      public static final int RANDOM
      See Also:

    • SEQUENTIAL

      public static final int SEQUENTIAL
      See Also:

    • amountOfPagesUnknown

      private boolean amountOfPagesUnknown
      According to D.4.2 - Bit 1
      • true if amount of pages is unknown, amount of pages field is not present
      • false if there is a field in the file header where the amount of pages can be read

    • amountOfPages

      private int amountOfPages
      According to D.4.3 - Number of pages field (4 bytes). Only present if amountOfPagesUnknown is false.

    • gbUseExtTemplate

      private boolean gbUseExtTemplate
      Defines whether extended Template is used.

    • subInputStream

      private final SubInputStream subInputStream
      This is the source data stream wrapped into a SubInputStream.

    • globalSegments

      private JBIG2Globals globalSegments
      Holds a load of segments, that aren't associated with a page.

  • Constructor Details

  • Method Details

    • getGlobalSegment

      SegmentHeader getGlobalSegment(int segmentNr)
      Retrieves the segment with the given segment number considering only segments that aren't associated with a page.
      Parameters:
      segmentNr - - The number of the wanted segment.
      Returns:
      The requested SegmentHeader.

    • getPage

      protected JBIG2Page getPage(int pageNumber)
      Retrieves a JBIG2Page specified by the given page number.
      Parameters:
      pageNumber - - The page number of the wanted JBIG2Page.
      Returns:
      The requested JBIG2Page.

    • getAmountOfPages

      protected int getAmountOfPages() throws IOException
      Retrieves the amount of pages in this JBIG2 document. If the pages are striped, the document will be completely parsed and the amount of pages will be gathered.
      Returns:
      The amount of pages in this JBIG2 document.
      Throws:
      IOException

    • mapStream

      private void mapStream() throws IOException
      This method maps the stream and stores all segments.
      Throws:
      IOException

    • isFileHeaderPresent

      private boolean isFileHeaderPresent() throws IOException
      Throws:
      IOException

    • determineRandomDataOffsets

      private void determineRandomDataOffsets(List<SegmentHeader> segments, long offset)
      Determines the start of the data parts and sets the offset.
      Parameters:
      segments -
      offset -

    • parseFileHeader

      private void parseFileHeader() throws IOException
      This method reads the stream and sets variables for information about organization type and length etc.
      Throws:
      IOException

    • reachedEndOfStream

      private boolean reachedEndOfStream(long offset) throws IOException
      This method checks, if the stream is at its end to avoid EOFExceptions and reads 32 bits.
      Parameters:
      offset -
      Returns:
    • true if end of stream reached
    • false if there are more bytes to read
      • Throws:
      IOException

    • getGlobalSegments

      protected JBIG2Globals getGlobalSegments()

    • isAmountOfPagesUnknown

      protected boolean isAmountOfPagesUnknown()

    • isGbUseExtTemplate

      boolean isGbUseExtTemplate()