com.sun.pdfview
Class PDFObject

java.lang.Object
  extended by com.sun.pdfview.PDFObject

public class PDFObject
extends java.lang.Object

a class encapsulating all the possibilities of content for an object in a PDF file.

A PDF object can be a simple type, like a Boolean, a Number, a String, or the Null value. It can also be a NAME, which looks like a string, but is a special type in PDF files, like "/Name".

A PDF object can also be complex types, including Array; Dictionary; Stream, which is a Dictionary plus an array of bytes; or Indirect, which is a reference to some other PDF object. Indirect references will always be dereferenced by the time any data is returned from one of the methods in this class.


Field Summary
static int ARRAY
          an array of PDFObjects
static int BOOLEAN
          a Boolean
static int DICTIONARY
          a Hashmap that maps String names to PDFObjects
static int INDIRECT
          an indirect reference
static int KEYWORD
          a special PDF bare word, like R, obj, true, false, etc
static int NAME
          a special string, seen in PDF files as /Name
static int NULL
          the NULL object (there is only one)
static PDFObject nullObj
          the NULL PDFObject
static int NUMBER
          a Number, represented as a double
static int OBJ_NUM_EMBEDDED
          When a value of objNum or objGen, indicates that the object is not top-level, and is embedded in another object
static int OBJ_NUM_TRAILER
          When a value of objNum or objGen, indicates that the object is not top-level, and is embedded directly in the trailer.
static int STREAM
          a Stream: a Hashmap with a byte array
static int STRING
          a String
 
Constructor Summary
PDFObject(java.lang.Object obj)
          create a new PDFObject that is the closest match to a given Java object.
PDFObject(PDFFile owner, int type, java.lang.Object value)
          create a new simple PDFObject with a type and a value
PDFObject(PDFFile owner, PDFXref xref)
          create a new PDFObject based on a PDFXref
 
Method Summary
 PDFObject dereference()
          Make sure that this object is dereferenced.
 boolean equals(java.lang.Object o)
          Test whether two PDFObject are equal.
 PDFObject[] getArray()
          get the value as a PDFObject[].
 PDFObject getAt(int idx)
          if this object is an ARRAY, get the PDFObject at some position in the array.
 boolean getBooleanValue()
          get the value as a boolean.
 java.lang.Object getCache()
          get the value in the cache.
 PDFDecrypter getDecrypter()
           
 java.util.HashMap<java.lang.String,PDFObject> getDictionary()
          get the dictionary as a HashMap.
 java.util.Iterator getDictKeys()
          get an Iterator over all the keys in the dictionary.
 PDFObject getDictRef(java.lang.String key)
          get the value associated with a particular key in the dictionary.
 double getDoubleValue()
          get the value as a double.
 float getFloatValue()
          get the value as a float.
 int getIntValue()
          get the value as an int.
 int getObjGen()
          Get the object generation number of this object; a negative value indicates that the object is not numbered, as it's not a top-level object: if the value is OBJ_NUM_EMBEDDED, it is because it's embedded within another object.
 int getObjNum()
          Get the object number of this object; a negative value indicates that the object is not numbered, as it's not a top-level object: if the value is OBJ_NUM_EMBEDDED, it is because it's embedded within another object.
 byte[] getStream()
          get the stream from this object.
 byte[] getStream(java.util.Set<java.lang.String> filterLimits)
           
 java.nio.ByteBuffer getStreamBuffer()
          get the stream from this object as a byte buffer.
 java.nio.ByteBuffer getStreamBuffer(java.util.Set<java.lang.String> filterLimits)
          get the stream from this object as a byte buffer.
 java.lang.String getStringValue()
          get the value as a String.
 java.lang.String getTextStringValue()
          Get the value as a text string; i.e., a string encoded in UTF-16BE or PDFDocEncoding.
 int getType()
          get the type of this object.
 boolean isDictType(java.lang.String match)
          returns true only if this object is a DICTIONARY or a STREAM, and the "Type" entry in the dictionary matches a given value.
 boolean isIndirect()
          Identify whether the object is currently an indirect/cross-reference
 void setCache(java.lang.Object obj)
          set the cached value.
 void setObjectId(int objNum, int objGen)
          Set the object identifiers
 void setStream(java.nio.ByteBuffer data)
          set the stream of this object.
 java.lang.String toString()
          return a representation of this PDFObject as a String.
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

INDIRECT

public static final int INDIRECT
an indirect reference

See Also:
Constant Field Values

BOOLEAN

public static final int BOOLEAN
a Boolean

See Also:
Constant Field Values

NUMBER

public static final int NUMBER
a Number, represented as a double

See Also:
Constant Field Values

STRING

public static final int STRING
a String

See Also:
Constant Field Values

NAME

public static final int NAME
a special string, seen in PDF files as /Name

See Also:
Constant Field Values

ARRAY

public static final int ARRAY
an array of PDFObjects

See Also:
Constant Field Values

DICTIONARY

public static final int DICTIONARY
a Hashmap that maps String names to PDFObjects

See Also:
Constant Field Values

STREAM

public static final int STREAM
a Stream: a Hashmap with a byte array

See Also:
Constant Field Values

NULL

public static final int NULL
the NULL object (there is only one)

See Also:
Constant Field Values

KEYWORD

public static final int KEYWORD
a special PDF bare word, like R, obj, true, false, etc

See Also:
Constant Field Values

OBJ_NUM_EMBEDDED

public static final int OBJ_NUM_EMBEDDED
When a value of objNum or objGen, indicates that the object is not top-level, and is embedded in another object

See Also:
Constant Field Values

OBJ_NUM_TRAILER

public static final int OBJ_NUM_TRAILER
When a value of objNum or objGen, indicates that the object is not top-level, and is embedded directly in the trailer.

See Also:
Constant Field Values

nullObj

public static final PDFObject nullObj
the NULL PDFObject

Constructor Detail

PDFObject

public PDFObject(PDFFile owner,
                 int type,
                 java.lang.Object value)
create a new simple PDFObject with a type and a value

Parameters:
owner - the PDFFile in which this object resides, used for dereferencing. This may be null.
type - the type of object
value - the value. For DICTIONARY, this is a HashMap. for ARRAY it's an ArrayList. For NUMBER, it's a Double. for BOOLEAN, it's Boolean.TRUE or Boolean.FALSE. For everything else, it's a String.

PDFObject

public PDFObject(java.lang.Object obj)
          throws PDFParseException
create a new PDFObject that is the closest match to a given Java object. Possibilities include Double, String, PDFObject[], HashMap, Boolean, or PDFParser.Tok, which should be "true" or "false" to turn into a BOOLEAN.

Parameters:
obj - the sample Java object to convert to a PDFObject.
Throws:
PDFParseException - if the object isn't one of the above examples, and can't be turned into a PDFObject.

PDFObject

public PDFObject(PDFFile owner,
                 PDFXref xref)
create a new PDFObject based on a PDFXref

Parameters:
owner - the PDFFile from which the PDFXref was drawn
xref - the PDFXref to turn into a PDFObject
Method Detail

getType

public int getType()
            throws java.io.IOException
get the type of this object. The object will be dereferenced, so INDIRECT will never be returned.

Returns:
the type of the object
Throws:
java.io.IOException

setStream

public void setStream(java.nio.ByteBuffer data)
set the stream of this object. It should have been a DICTIONARY before the call.

Parameters:
data - the data, as a ByteBuffer.

getCache

public java.lang.Object getCache()
                          throws java.io.IOException
get the value in the cache. May become null at any time.

Returns:
the cached value, or null if the value has been garbage collected.
Throws:
java.io.IOException

setCache

public void setCache(java.lang.Object obj)
              throws java.io.IOException
set the cached value. The object may be garbage collected if no other reference exists to it.

Parameters:
obj - the object to be cached
Throws:
java.io.IOException

getStream

public byte[] getStream(java.util.Set<java.lang.String> filterLimits)
                 throws java.io.IOException
Throws:
java.io.IOException

getStream

public byte[] getStream()
                 throws java.io.IOException
get the stream from this object. Will return null if this object isn't a STREAM.

Returns:
the stream, or null, if this isn't a STREAM.
Throws:
java.io.IOException

getStreamBuffer

public java.nio.ByteBuffer getStreamBuffer()
                                    throws java.io.IOException
get the stream from this object as a byte buffer. Will return null if this object isn't a STREAM.

Returns:
the buffer, or null, if this isn't a STREAM.
Throws:
java.io.IOException

getStreamBuffer

public java.nio.ByteBuffer getStreamBuffer(java.util.Set<java.lang.String> filterLimits)
                                    throws java.io.IOException
get the stream from this object as a byte buffer. Will return null if this object isn't a STREAM.

Returns:
the buffer, or null, if this isn't a STREAM.
Throws:
java.io.IOException

getIntValue

public int getIntValue()
                throws java.io.IOException
get the value as an int. Will return 0 if this object isn't a NUMBER.

Throws:
java.io.IOException

getFloatValue

public float getFloatValue()
                    throws java.io.IOException
get the value as a float. Will return 0 if this object isn't a NUMBER

Throws:
java.io.IOException

getDoubleValue

public double getDoubleValue()
                      throws java.io.IOException
get the value as a double. Will return 0 if this object isn't a NUMBER.

Throws:
java.io.IOException

getStringValue

public java.lang.String getStringValue()
                                throws java.io.IOException
get the value as a String. Will return null if the object isn't a STRING, NAME, or KEYWORD. This method will NOT convert a NUMBER to a String. If the string is actually a text string (i.e., may be encoded in UTF16-BE or PdfDocEncoding), then one should use getTextStringValue() or use one of the PDFStringUtil methods on the result from this method. The string value represents exactly the sequence of 8 bit characters present in the file, decrypted and decoded as appropriate, into a string containing only 8 bit character values - that is, each char will be between 0 and 255.

Throws:
java.io.IOException

getTextStringValue

public java.lang.String getTextStringValue()
                                    throws java.io.IOException
Get the value as a text string; i.e., a string encoded in UTF-16BE or PDFDocEncoding. Simple latin alpha-numeric characters are preserved in both these encodings.

Returns:
the text string value
Throws:
java.io.IOException

getArray

public PDFObject[] getArray()
                     throws java.io.IOException
get the value as a PDFObject[]. If this object is an ARRAY, will return the array. Otherwise, will return an array of one element with this object as the element.

Throws:
java.io.IOException

getBooleanValue

public boolean getBooleanValue()
                        throws java.io.IOException
get the value as a boolean. Will return false if this object is not a BOOLEAN

Throws:
java.io.IOException

getAt

public PDFObject getAt(int idx)
                throws java.io.IOException
if this object is an ARRAY, get the PDFObject at some position in the array. If this is not an ARRAY, returns null.

Throws:
java.io.IOException

getDictKeys

public java.util.Iterator getDictKeys()
                               throws java.io.IOException
get an Iterator over all the keys in the dictionary. If this object is not a DICTIONARY or a STREAM, returns an Iterator over the empty list.

Throws:
java.io.IOException

getDictionary

public java.util.HashMap<java.lang.String,PDFObject> getDictionary()
                                                            throws java.io.IOException
get the dictionary as a HashMap. If this isn't a DICTIONARY or a STREAM, returns null

Throws:
java.io.IOException

getDictRef

public PDFObject getDictRef(java.lang.String key)
                     throws java.io.IOException
get the value associated with a particular key in the dictionary. If this isn't a DICTIONARY or a STREAM, or there is no such key, returns null.

Throws:
java.io.IOException

isDictType

public boolean isDictType(java.lang.String match)
                   throws java.io.IOException
returns true only if this object is a DICTIONARY or a STREAM, and the "Type" entry in the dictionary matches a given value.

Parameters:
match - the expected value for the "Type" key in the dictionary
Returns:
whether the dictionary is of the expected type
Throws:
java.io.IOException

getDecrypter

public PDFDecrypter getDecrypter()

setObjectId

public void setObjectId(int objNum,
                        int objGen)
Set the object identifiers

Parameters:
objNum - the object number
objGen - the object generation number

getObjNum

public int getObjNum()
Get the object number of this object; a negative value indicates that the object is not numbered, as it's not a top-level object: if the value is OBJ_NUM_EMBEDDED, it is because it's embedded within another object. If the value is OBJ_NUM_TRAILER, it's because it's an object from the trailer.

Returns:
the object number, if positive

getObjGen

public int getObjGen()
Get the object generation number of this object; a negative value indicates that the object is not numbered, as it's not a top-level object: if the value is OBJ_NUM_EMBEDDED, it is because it's embedded within another object. If the value is OBJ_NUM_TRAILER, it's because it's an object from the trailer.

Returns:
the object generation number, if positive

toString

public java.lang.String toString()
return a representation of this PDFObject as a String. Does NOT dereference anything: this is the only method that allows you to distinguish an INDIRECT PDFObject.

Overrides:
toString in class java.lang.Object

dereference

public PDFObject dereference()
                      throws java.io.IOException
Make sure that this object is dereferenced. Use the cache of an indirect object to cache the dereferenced value, if possible.

Throws:
java.io.IOException

isIndirect

public boolean isIndirect()
Identify whether the object is currently an indirect/cross-reference

Returns:
whether currently indirect

equals

public boolean equals(java.lang.Object o)
Test whether two PDFObject are equal. Objects are equal IFF they are the same reference OR they are both indirect objects with the same id and generation number in their xref

Overrides:
equals in class java.lang.Object