Begin the scope of a prefix-URI Namespace mapping.
<p>The information from this event is not necessary for
normal Namespace processing: the SAX XML reader will
automatically replace prefixes for element and attribute
names when the <code>http://xml.org/sax/features/namespaces</code>
feature is <var>true</var> (the default).</p>
<p>There are cases, however, when applications need to
use prefixes in character data or in attribute values,
where they cannot safely be expanded automatically; the
start/endPrefixMapping event supplies the information
to the application to expand prefixes in those contexts
itself, if necessary.</p>
<p>Note that start/endPrefixMapping events are not
guaranteed to be properly nested relative to each other:
all startPrefixMapping events will occur immediately before the
corresponding {@link #startElement startElement} event,
and all {@link #endPrefixMapping endPrefixMapping}
events will occur immediately after the corresponding
{@link #endElement endElement} event,
but their order is not otherwise
guaranteed.</p>
<p>There should never be start/endPrefixMapping events for the
"xml" prefix, since it is predeclared and immutable.</p>
@param prefix the Namespace prefix being declared.
An empty string is used for the default element namespace,
which has no prefix.
@param uri the Namespace URI the prefix is mapped to
@throws org.xml.sax.SAXException the client may throw
an exception during processing
@see #endPrefixMapping
@see #startElement
Begin the scope of a prefix-URI Namespace mapping.
<p>The information from this event is not necessary for normal Namespace processing: the SAX XML reader will automatically replace prefixes for element and attribute names when the <code>http://xml.org/sax/features/namespaces</code> feature is <var>true</var> (the default).</p>
<p>There are cases, however, when applications need to use prefixes in character data or in attribute values, where they cannot safely be expanded automatically; the start/endPrefixMapping event supplies the information to the application to expand prefixes in those contexts itself, if necessary.</p>
<p>Note that start/endPrefixMapping events are not guaranteed to be properly nested relative to each other: all startPrefixMapping events will occur immediately before the corresponding {@link #startElement startElement} event, and all {@link #endPrefixMapping endPrefixMapping} events will occur immediately after the corresponding {@link #endElement endElement} event, but their order is not otherwise guaranteed.</p>
<p>There should never be start/endPrefixMapping events for the "xml" prefix, since it is predeclared and immutable.</p>
@param prefix the Namespace prefix being declared. An empty string is used for the default element namespace, which has no prefix. @param uri the Namespace URI the prefix is mapped to @throws org.xml.sax.SAXException the client may throw an exception during processing @see #endPrefixMapping @see #startElement