org.apache.pdfbox.pdfparser

Class BaseParser

java.lang.Object

org.apache.pdfbox.pdfparser.BaseParser

Direct Known Subclasses:

ConformingPDFParser, PDFObjectStreamParser, PDFParser, PDFStreamParser, PDFXrefStreamParser, VisualSignatureParser

public abstract class BaseParser
extends Object

This class is used to contain parsing logic that will be used by both the PDFParser and the COSStreamParser.

Version:

$Revision$

Author:

Ben Litchfield

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEF This is a string constant that will be used for comparisons.
protected COSDocument	document This is the document that will be parsed.
static byte[]	ENDOBJ This is a byte array that will be used for comparisons.
static byte[]	ENDSTREAM This is a byte array that will be used for comparisons.
protected boolean	forceParsing Flag to skip malformed or otherwise unparseable input where possible.
protected PushBackInputStream	pdfSource This is the stream that will be read from.
static String	PROP_PUSHBACK_SIZE system property allowing to define size of push back buffer.

Constructor Summary

Constructors

Modifier	Constructor and Description
	BaseParser() Default constructor.
protected	BaseParser(byte[] input) Constructor.
	BaseParser(InputStream input) Constructor.
	BaseParser(InputStream input, boolean forceParsingValue) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	clearResources() Release all used resources.
protected boolean	isClosing() This will tell if the next character is a closing brace( close of PDF array ).
protected boolean	isClosing(int c) This will tell if the next character is a closing brace( close of PDF array ).
protected boolean	isEndOfName(char ch) Determine if a character terminates a PDF name.
protected boolean	isEOL() This will tell if the next byte to be read is an end of line byte.
protected boolean	isEOL(int c) This will tell if the next byte to be read is an end of line byte.
protected boolean	isWhitespace() This will tell if the next byte is whitespace or not.
protected boolean	isWhitespace(int c) This will tell if the next byte is whitespace or not.
protected COSBoolean	parseBoolean() This will parse a boolean object from the stream.
protected COSArray	parseCOSArray() This will parse a PDF array object.
protected COSDictionary	parseCOSDictionary() This will parse a PDF dictionary.
protected COSName	parseCOSName() This will parse a PDF name from the stream.
protected COSStream	parseCOSStream(COSDictionary dic, RandomAccess file) This will read a COSStream from the input stream.
protected COSString	parseCOSString() This will parse a PDF string.
protected COSString	parseCOSString(boolean isDictionary) Deprecated. Not needed anymore. Use parseCOSString() instead. PDFBOX-1437
protected COSBase	parseDirObject() This will parse a directory object from the stream.
protected String	readExpectedString(String theString) This will read bytes until the end of line marker occurs.
protected int	readGenerationNumber() This will read a integer from the Stream and throw an IllegalArgumentException if the integer value has more than the maximum object revision (i.e. : bigger than GENERATION_NUMBER_THRESHOLD)
protected int	readInt() This will read an integer from the stream.
protected String	readLine() This will read bytes until the first end of line marker occurs.
protected long	readLong() This will read an long from the stream.
protected long	readObjectNumber() This will read a long from the Stream and throw an IllegalArgumentException if the long value has more than 10 digits (i.e. : bigger than OBJECT_NUMBER_THRESHOLD)
protected String	readString() This will read the next string from the stream.
protected String	readString(int length) This will read the next string from the stream up to a certain length.
protected StringBuilder	readStringNumber() This method is used to read a token by the readInt() method and the readLong() method.
protected void	readUntilEndStream(OutputStream out) This method will read through the current stream object until we find the keyword "endstream" meaning we're at the end of this object.
void	setDocument(COSDocument doc) Set the document for this stream.
protected void	skipSpaces() This will skip all spaces and comments that are present.

Methods inherited from class java.lang.Object

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

Field Detail

PROP_PUSHBACK_SIZE

public static final String PROP_PUSHBACK_SIZE

system property allowing to define size of push back buffer.

See Also:

Constant Field Values

ENDSTREAM

public static final byte[] ENDSTREAM

This is a byte array that will be used for comparisons.

ENDOBJ

public static final byte[] ENDOBJ

This is a byte array that will be used for comparisons.

DEF

public static final String DEF

This is a string constant that will be used for comparisons.

See Also:

Constant Field Values

pdfSource

protected PushBackInputStream pdfSource

This is the stream that will be read from.

document

protected COSDocument document

This is the document that will be parsed.

forceParsing

protected final boolean forceParsing

Flag to skip malformed or otherwise unparseable input where possible.

Constructor Detail

BaseParser

public BaseParser()

Default constructor.

BaseParser

public BaseParser(InputStream input,
          boolean forceParsingValue)
           throws IOException

Constructor.

Parameters:

input - The input stream to read the data from.

forceParsingValue - flag to skip malformed or otherwise unparseable input where possible

Throws:

IOException - If there is an error reading the input stream.

Since:

Apache PDFBox 1.3.0

BaseParser

public BaseParser(InputStream input)
           throws IOException

Constructor.

Parameters:

input - The input stream to read the data from.

Throws:

IOException - If there is an error reading the input stream.

BaseParser

protected BaseParser(byte[] input)
              throws IOException

Constructor.

Parameters:

input - The array to read the data from.

Throws:

IOException - If there is an error reading the byte data.

Method Detail

setDocument

public void setDocument(COSDocument doc)

Set the document for this stream.

Parameters:

doc - The current document.

parseCOSDictionary

protected COSDictionary parseCOSDictionary()
                                    throws IOException

This will parse a PDF dictionary.

Returns:

The parsed dictionary.

Throws:

IOException - IF there is an error reading the stream.

parseCOSStream

protected COSStream parseCOSStream(COSDictionary dic,
                       RandomAccess file)
                            throws IOException

This will read a COSStream from the input stream.

Parameters:

file - The file to write the stream to when reading.

dic - The dictionary that goes with this stream.

Returns:

The parsed pdf stream.

Throws:

IOException - If there is an error reading the stream.

readUntilEndStream

protected void readUntilEndStream(OutputStream out)
                           throws IOException

This method will read through the current stream object until we find the keyword "endstream" meaning we're at the end of this object. Some pdf files, however, forget to write some endstream tags and just close off objects with an "endobj" tag so we have to handle this case as well. This method is optimized using buffered IO and reduced number of byte compare operations.

Parameters:

out - stream we write out to.

Throws:

IOException

parseCOSString

@Deprecated
protected COSString parseCOSString(boolean isDictionary)
                            throws IOException

Deprecated. Not needed anymore. Use parseCOSString() instead. PDFBOX-1437

This will parse a PDF string.

Parameters:

isDictionary - indicates if the stream is a dictionary or not

Returns:

The parsed PDF string.

Throws:

IOException - If there is an error reading from the stream.

parseCOSString

protected COSString parseCOSString()
                            throws IOException

This will parse a PDF string.

Returns:

The parsed PDF string.

Throws:

IOException - If there is an error reading from the stream.

parseCOSArray

protected COSArray parseCOSArray()
                          throws IOException

This will parse a PDF array object.

Returns:

The parsed PDF array.

Throws:

IOException - If there is an error parsing the stream.

isEndOfName

protected boolean isEndOfName(char ch)

Determine if a character terminates a PDF name.

Parameters:

ch - The character

Returns:

true if the character terminates a PDF name, otherwise false.

parseCOSName

protected COSName parseCOSName()
                        throws IOException

This will parse a PDF name from the stream.

Returns:

The parsed PDF name.

Throws:

IOException - If there is an error reading from the stream.

parseBoolean

protected COSBoolean parseBoolean()
                           throws IOException

This will parse a boolean object from the stream.

Returns:

The parsed boolean object.

Throws:

IOException - If an IO error occurs during parsing.

parseDirObject

protected COSBase parseDirObject()
                          throws IOException

This will parse a directory object from the stream.

Returns:

The parsed object.

Throws:

IOException - If there is an error during parsing.

readString

protected String readString()
                     throws IOException

This will read the next string from the stream.

Returns:

The string that was read from the stream.

Throws:

IOException - If there is an error reading from the stream.

readExpectedString

protected String readExpectedString(String theString)
                             throws IOException

This will read bytes until the end of line marker occurs.

Parameters:

theString - The next expected string in the stream.

Returns:

The characters between the current position and the end of the line.

Throws:

IOException - If there is an error reading from the stream or theString does not match what was read.

readString

protected String readString(int length)
                     throws IOException

This will read the next string from the stream up to a certain length.

Parameters:

length - The length to stop reading at.

Returns:

The string that was read from the stream of length 0 to length.

Throws:

IOException - If there is an error reading from the stream.

isClosing

protected boolean isClosing()
                     throws IOException

This will tell if the next character is a closing brace( close of PDF array ).

Returns:

true if the next byte is ']', false otherwise.

Throws:

IOException - If an IO error occurs.

isClosing

protected boolean isClosing(int c)

This will tell if the next character is a closing brace( close of PDF array ).

Parameters:

c - The character to check against end of line

Returns:

true if the next byte is ']', false otherwise.

readLine

protected String readLine()
                   throws IOException

This will read bytes until the first end of line marker occurs. Note: if you later unread the results of this function, you'll need to add a newline character to the end of the string.

Returns:

The characters between the current position and the end of the line.

Throws:

IOException - If there is an error reading from the stream.

isEOL

protected boolean isEOL()
                 throws IOException

This will tell if the next byte to be read is an end of line byte.

Returns:

true if the next byte is 0x0A or 0x0D.

Throws:

IOException - If there is an error reading from the stream.

isEOL

protected boolean isEOL(int c)

This will tell if the next byte to be read is an end of line byte.

Parameters:

c - The character to check against end of line

Returns:

true if the next byte is 0x0A or 0x0D.

isWhitespace

protected boolean isWhitespace()
                        throws IOException

This will tell if the next byte is whitespace or not.

Returns:

true if the next byte in the stream is a whitespace character.

Throws:

IOException - If there is an error reading from the stream.

isWhitespace

protected boolean isWhitespace(int c)

This will tell if the next byte is whitespace or not. These values are specified in table 1 (page 12) of ISO 32000-1:2008.

Parameters:

c - The character to check against whitespace

Returns:

true if the next byte in the stream is a whitespace character.

skipSpaces

protected void skipSpaces()
                   throws IOException

This will skip all spaces and comments that are present.

Throws:

IOException - If there is an error reading from the stream.

readObjectNumber

protected long readObjectNumber()
                         throws IOException

This will read a long from the Stream and throw an IllegalArgumentException if the long value has more than 10 digits (i.e. : bigger than OBJECT_NUMBER_THRESHOLD)

Returns:

the object number being read.

Throws:

IOException - if an I/O error occurs

readGenerationNumber

protected int readGenerationNumber()
                            throws IOException

This will read a integer from the Stream and throw an IllegalArgumentException if the integer value has more than the maximum object revision (i.e. : bigger than GENERATION_NUMBER_THRESHOLD)

Returns:

the generation number being read.

Throws:

IOException - if an I/O error occurs

readInt

protected int readInt()
               throws IOException

This will read an integer from the stream.

Returns:

The integer that was read from the stream.

Throws:

IOException - If there is an error reading from the stream.

readLong

protected long readLong()
                 throws IOException

This will read an long from the stream.

Returns:

The long that was read from the stream.

Throws:

IOException - If there is an error reading from the stream.

readStringNumber

protected final StringBuilder readStringNumber()
                                        throws IOException

This method is used to read a token by the readInt() method and the readLong() method.

Returns:

the token to parse as integer or long by the calling method.

Throws:

IOException - throws by the pdfSource methods.

clearResources

public void clearResources()

Release all used resources.