COSParser (Apache PDFBox 2.0.0 API)

java.lang.Object
- org.apache.pdfbox.pdfparser.BaseParser
- - org.apache.pdfbox.pdfparser.COSParser

Direct Known Subclasses:

FDFParser, PDFParser
```
public class COSParser
extends BaseParser
```
PDF-Parser which first reads startxref and xref tables in order to know valid objects and parse only these objects. First PDFParser.parse() or FDFParser.parse() must be called before page objects can be retrieved, e.g. PDFParser.getPDDocument(). This class is a much enhanced version of QuickParser presented in PDFBOX-1104 by Jeremy Villalobos.

Field Summary

Fields
Modifier and Type	Field and Description
`protected static char[]`	`EOF_MARKER` EOF-marker.
`protected long`	`fileLen` file length.
`protected boolean`	`initialParseDone`
`protected static char[]`	`OBJ_MARKER` obj-marker.
`protected SecurityHandler`	`securityHandler` The security handler.
`protected RandomAccessRead`	`source`
`static String`	`SYSPROP_EOFLOOKUPRANGE` The range within the %%EOF marker will be searched.
`static String`	`SYSPROP_PARSEMINIMAL` Only parse the PDF file minimally allowing access to basic information.
`static String`	`TMP_FILE_PREFIX` The prefix for the temp file being used.
`protected XrefTrailerResolver`	`xrefTrailerResolver` Collects all Xref/trailer objects and resolves them into single object using startxref reference.

Fields inherited from class org.apache.pdfbox.pdfparser.BaseParser
A, ASCII_CR, ASCII_LF, B, D, DEF, document, E, ENDOBJ_STRING, ENDSTREAM_STRING, J, M, N, O, R, S, seqSource, STREAM_STRING, T

Constructor Summary

Constructors
Constructor and Description

COSParser(RandomAccessRead source)
Default constructor.

Constructors
Constructor and Description
`COSParser(RandomAccessRead source)` Default constructor.

Method Summary

Methods
Modifier and Type	Method and Description
`COSDocument`	`getDocument()` This will get the document that was parsed.
`protected long`	`getStartxrefOffset()` Looks for and parses startxref.
`boolean`	`isLenient()` Return true if parser is lenient.
`protected int`	`lastIndexOf(char[] pattern, byte[] buf, int endOff)` Searches last appearance of pattern within buffer.
`protected COSStream`	`parseCOSStream(COSDictionary dic)` This will read a COSStream from the input stream using length attribute within dictionary.
`protected void`	`parseDictObjects(COSDictionary dict, COSName... excludeObjects)` Will parse every object necessary to load a single page from the pdf document.
`protected boolean`	`parseFDFHeader()` Parse the header of a fdf.
`protected COSBase`	`parseObjectDynamically(COSObject obj, boolean requireExistingNotCompressedObj)` This will parse the next object from the stream and add it to the local state.
`protected COSBase`	`parseObjectDynamically(long objNr, int objGenNr, boolean requireExistingNotCompressedObj)` This will parse the next object from the stream and add it to the local state.
`protected boolean`	`parsePDFHeader()` Parse the header of a pdf.
`protected COSBase`	`parseTrailerValuesDynamically(COSDictionary trailer)` Parse the values of the trailer dictionary and return the root object.
`protected COSDictionary`	`parseXref(long startXRefOffset)` Parses cross reference tables.
`protected boolean`	`parseXrefTable(long startByteOffset)` This will parse the xref table from the stream and add it to the state The XrefTable contents are ignored.
`protected COSDictionary`	`rebuildTrailer()` Rebuild the trailer dictionary if startxref can't be found.
`void`	`setEOFLookupRange(int byteCount)` Sets how many trailing bytes of PDF file are searched for EOF marker and 'startxref' marker.
`void`	`setLenient(boolean lenient)` Change the parser leniency flag.

Methods inherited from class org.apache.pdfbox.pdfparser.BaseParser
isClosing, isClosing, isDigit, isDigit, isEndOfName, isEOL, isEOL, isSpace, isSpace, isWhitespace, isWhitespace, parseBoolean, parseCOSArray, parseCOSDictionary, parseCOSName, parseCOSString, parseDirObject, readExpectedChar, readExpectedString, readExpectedString, readGenerationNumber, readInt, readLine, readLong, readObjectNumber, readString, readString, readStringNumber, skipSpaces, skipWhiteSpaces

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - source
```
protected final RandomAccessRead source
```
  - SYSPROP_PARSEMINIMAL
```
public static final String SYSPROP_PARSEMINIMAL
```
    Only parse the PDF file minimally allowing access to basic information.
    
    See Also:
    Constant Field Values
  - SYSPROP_EOFLOOKUPRANGE
```
public static final String SYSPROP_EOFLOOKUPRANGE
```
    The range within the %%EOF marker will be searched. Useful if there are additional characters after %%EOF within the PDF.
    
    See Also:
    Constant Field Values
  - EOF_MARKER
```
protected static final char[] EOF_MARKER
```
    EOF-marker.
  - OBJ_MARKER
```
protected static final char[] OBJ_MARKER
```
    obj-marker.
  - fileLen
```
protected long fileLen
```
    file length.
  - initialParseDone
```
protected boolean initialParseDone
```
  - securityHandler
```
protected SecurityHandler securityHandler
```
    The security handler.
  - xrefTrailerResolver
```
protected XrefTrailerResolver xrefTrailerResolver
```
    Collects all Xref/trailer objects and resolves them into single object using startxref reference.
  - TMP_FILE_PREFIX
```
public static final String TMP_FILE_PREFIX
```
    The prefix for the temp file being used.
    
    See Also:
    Constant Field Values
- Constructor Detail
  - COSParser
```
public COSParser(RandomAccessRead source)
```
    Default constructor.
- Method Detail
  - setEOFLookupRange
```
public void setEOFLookupRange(int byteCount)
```
    Sets how many trailing bytes of PDF file are searched for EOF marker and 'startxref' marker. If not set we use default value DEFAULT_TRAIL_BYTECOUNT.
    We check that new value is at least 16. However for practical use cases this value should not be lower than 1000; even 2000 was found to not be enough in some cases where some trailing garbage like HTML snippets followed the EOF marker.
    
    In case system property SYSPROP_EOFLOOKUPRANGE is defined this value will be set on initialization but can be overwritten later.
    
    Parameters:
    byteCount - number of trailing bytes
  - parseXref
```
protected COSDictionary parseXref(long startXRefOffset)
                           throws IOException
```
    Parses cross reference tables.
    
    Parameters:
    startXRefOffset - start offset of the first table
    
    Returns:
    the trailer dictionary
    
    Throws:
    
    IOException - if something went wrong
  - getStartxrefOffset
```
protected final long getStartxrefOffset()
                                 throws IOException
```
    Looks for and parses startxref. We first look for last '%%EOF' marker (within last DEFAULT_TRAIL_BYTECOUNT bytes (or range set via setEOFLookupRange(int)) and go back to find startxref.
    
    Returns:
    the offset of StartXref
    
    Throws:
    
    IOException - If something went wrong.
  - lastIndexOf
```
protected int lastIndexOf(char[] pattern,
              byte[] buf,
              int endOff)
```
    Searches last appearance of pattern within buffer. Lookup before _lastOff and goes back until 0.
    
    Parameters:
    pattern - pattern to search for
    buf - buffer to search pattern in
    endOff - offset (exclusive) where lookup starts at
    
    Returns:
    start offset of pattern within buffer or -1 if pattern could not be found
  - isLenient
```
public boolean isLenient()
```
    Return true if parser is lenient. Meaning auto healing capacity of the parser are used.
    
    Returns:
    true if parser is lenient
  - setLenient
```
public void setLenient(boolean lenient)
```
    Change the parser leniency flag. This method can only be called before the parsing of the file.
    
    Parameters:
    lenient - try to handle malformed PDFs.
  - parseDictObjects
```
protected void parseDictObjects(COSDictionary dict,
                    COSName... excludeObjects)
                         throws IOException
```
    Will parse every object necessary to load a single page from the pdf document. We try our best to order objects according to offset in file before reading to minimize seek operations.
    
    Parameters:
    dict - the COSObject from the parent pages.
    excludeObjects - dictionary object reference entries with these names will not be parsed
    
    Throws:
    
    IOException - if something went wrong
  - parseObjectDynamically
```
protected final COSBase parseObjectDynamically(COSObject obj,
                             boolean requireExistingNotCompressedObj)
                                        throws IOException
```
    This will parse the next object from the stream and add it to the local state.
    
    Parameters:
    obj - object to be parsed (we only take object number and generation number for lookup start offset)
    requireExistingNotCompressedObj - if true object to be parsed must not be contained within compressed stream
    
    Returns:
    the parsed object (which is also added to document object)
    
    Throws:
    
    IOException - If an IO error occurs.
  - parseObjectDynamically
```
protected COSBase parseObjectDynamically(long objNr,
                             int objGenNr,
                             boolean requireExistingNotCompressedObj)
                                  throws IOException
```
    This will parse the next object from the stream and add it to the local state. It's reduced to parsing an indirect object.
    
    Parameters:
    objNr - object number of object to be parsed
    objGenNr - object generation number of object to be parsed
    requireExistingNotCompressedObj - if true the object to be parsed must be defined in xref (comment: null objects may be missing from xref) and it must not be a compressed object within object stream (this is used to circumvent being stuck in a loop in a malicious PDF)
    
    Returns:
    the parsed object (which is also added to document object)
    
    Throws:
    
    IOException - If an IO error occurs.
  - parseCOSStream
```
protected COSStream parseCOSStream(COSDictionary dic)
                            throws IOException
```
    This will read a COSStream from the input stream using length attribute within dictionary. If length attribute is a indirect reference it is first resolved to get the stream length. This means we copy stream data without testing for 'endstream' or 'endobj' and thus it is no problem if these keywords occur within stream. We require 'endstream' to be found after stream data is read.
    
    Parameters:
    dic - dictionary that goes with this stream.
    
    Returns:
    parsed pdf stream.
    
    Throws:
    
    IOException - if an error occurred reading the stream, like problems with reading length attribute, stream does not end with 'endstream' after data read, stream too short etc.
  - rebuildTrailer
```
protected final COSDictionary rebuildTrailer()
                                      throws IOException
```
    Rebuild the trailer dictionary if startxref can't be found.
    
    Returns:
    the rebuild trailer dictionary
    
    Throws:
    
    IOException - if something went wrong
  - parsePDFHeader
```
protected boolean parsePDFHeader()
                          throws IOException
```
    Parse the header of a pdf.
    
    Returns:
    true if a PDF header was found
    
    Throws:
    
    IOException - if something went wrong
  - parseFDFHeader
```
protected boolean parseFDFHeader()
                          throws IOException
```
    Parse the header of a fdf.
    
    Returns:
    true if a FDF header was found
    
    Throws:
    
    IOException - if something went wrong
  - parseXrefTable
```
protected boolean parseXrefTable(long startByteOffset)
                          throws IOException
```
    This will parse the xref table from the stream and add it to the state The XrefTable contents are ignored.
    
    Parameters:
    startByteOffset - the offset to start at
    
    Returns:
    false on parsing error
    
    Throws:
    
    IOException - If an IO error occurs.
  - getDocument
```
public COSDocument getDocument()
                        throws IOException
```
    This will get the document that was parsed. parse() must be called before this is called. When you are done with this document you must call close() on it to release resources.
    
    Returns:
    The document that was parsed.
    
    Throws:
    
    IOException - If there is an error getting the document.
  - parseTrailerValuesDynamically
```
protected COSBase parseTrailerValuesDynamically(COSDictionary trailer)
                                         throws IOException
```
    Parse the values of the trailer dictionary and return the root object.
    
    Parameters:
    trailer - The trailer dictionary.
    
    Returns:
    The parsed root object.
    
    Throws:
    
    IOException - If an IO error occurs or if the root object is missing in the trailer dictionary.

Class COSParser

Field Summary

Fields inherited from class org.apache.pdfbox.pdfparser.BaseParser

Constructor Summary

Method Summary

Methods inherited from class org.apache.pdfbox.pdfparser.BaseParser

Methods inherited from class java.lang.Object

Field Detail

source

SYSPROP_PARSEMINIMAL

SYSPROP_EOFLOOKUPRANGE

EOF_MARKER

OBJ_MARKER

fileLen

initialParseDone

securityHandler

xrefTrailerResolver

TMP_FILE_PREFIX

Constructor Detail

COSParser

Method Detail

setEOFLookupRange

parseXref

getStartxrefOffset

lastIndexOf

isLenient

setLenient

parseDictObjects

parseObjectDynamically

parseObjectDynamically

parseCOSStream

rebuildTrailer

parsePDFHeader

parseFDFHeader

parseXrefTable

getDocument

parseTrailerValuesDynamically