com.etymon.pjx
Class PdfNull

java.lang.Object
  com.etymon.pjx.PdfObject
      com.etymon.pjx.PdfNull

All Implemented Interfaces:

java.lang.Cloneable

public class PdfNull
extends PdfObject

Represents the PDF null object.

Field Summary

static PdfNull

NULL A PdfNull object representing the null value.

Constructor Summary

PdfNull()
Constructs a null object.

Method Summary

boolean	equals(java.lang.Object obj) Compares this instance with another PDF object for equality.
int	hashCode() Returns a hash code for this object.
static boolean	isNull(java.lang.Object obj) Checks whether an object represents a null value.
static PdfNull	valueOf() Returns a PdfNull object.
protected int	writePdf(PdfWriter w, boolean spacing) Writes this object in PDF format.

Methods inherited from class com.etymon.pjx.PdfObject

clone, filter, filterContents, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

NULL

public static final PdfNull NULL

A PdfNull object representing the null value.

Constructor Detail

PdfNull

public PdfNull()

Constructs a null object. In most cases there is no need to create a new instance of this class, and the valueOf() method is preferred.

Method Detail

isNull

public static boolean isNull(java.lang.Object obj)

Checks whether an object represents a null value. Note that this method differs slightly from equals(Object) in that this returns true when called with a null value. This method is useful for examining PDF objects, in which null and PdfNull should normally be considered equivalent. For example, if a dictionary value or an indirect object is PdfNull, it is equivalent to the object not existing.

Parameters:

obj - the object to examine.

Returns:

true if the object is either null or an instance of PdfNull; otherwise false is returned.

equals

public boolean equals(java.lang.Object obj)

Description copied from class: PdfObject

Compares this instance with another PDF object for equality.

Overrides:

equals in class PdfObject

Parameters:

obj - the object to compare this instance with.

Returns:

true if the PDF objects are equal.

hashCode

public int hashCode()

Description copied from class: PdfObject

Returns a hash code for this object.

Overrides:

hashCode in class PdfObject

Returns:

the hash code.

valueOf

public static PdfNull valueOf()

Returns a PdfNull object. This method is normally preferable to PdfNull() because it avoids allocating a new instance.

Returns:

the null object.

writePdf

protected int writePdf(PdfWriter w,
                       boolean spacing)
                throws java.io.IOException

Description copied from class: PdfObject

Writes this object in PDF format.

Specified by:

writePdf in class PdfObject

Parameters:

w - the PdfWriter to write to.

spacing - specifies whether to add white-space before the object. A value of true enables the addition of white-space. If the object begins with a PDF delimiter, then this option is ignored and no white-space is written.

Returns:

the number of bytes written by this method.

Throws:

java.io.IOException