@param publicId The entity's public identifier, or null.
@param systemId The entity's system identifier.
@return A new InputSource or null for the default.
@exception org.xml.sax.SAXException The client may throw
an exception during processing.
@exception java.io.IOException The client may throw an
I/O-related exception while obtaining the
new InputSource.
Filter an external entity resolution.
@param publicId The entity's public identifier, or null. @param systemId The entity's system identifier. @return A new InputSource or null for the default. @exception org.xml.sax.SAXException The client may throw an exception during processing. @exception java.io.IOException The client may throw an I/O-related exception while obtaining the new InputSource.