Return the public identifier for the current document event.
<p>The return value is the public identifier of the document
entity or of the external parsed entity in which the markup
triggering the event appears.</p>
@return A string containing the public identifier, or
null if none is available.
@see #getSystemId
Return the public identifier for the current document event.
<p>The return value is the public identifier of the document entity or of the external parsed entity in which the markup triggering the event appears.</p>
@return A string containing the public identifier, or null if none is available. @see #getSystemId