Returns the name of the character encoding for the entity.
If the encoding was declared externally (for example, in a MIME
Content-Type header), that will be the name returned. Else if there
was an
<?xml ...encoding='...'?> declaration at
the start of the document, that encoding name will be returned.
Otherwise the encoding will been inferred (normally to be UTF-8, or
some UTF-16 variant), and that inferred name will be returned.
When an InputSource
is used
to provide an entity's character stream, this method returns the
encoding provided in that input stream.
Note that some recent W3C specifications require that text
in some encodings be normalized, using Unicode Normalization
Form C, before processing. Such normalization must be performed
by applications, and would normally be triggered based on the
value returned by this method.
Encoding names may be those used by the underlying JVM,
and comparisons should be case-insensitive.
Returns:
Name of the character encoding being used to interpret
* the entity's text, or null if this was not provided for a *
character stream passed through an InputSource or is otherwise
not yet available in the current parsing state.