The Locator interface associates a SAX event with a document location.
If a SAX parser provides location information to the SAX application, it does so by implementing this interface and then passing an instance to the application using the document handler’s setDocumentLocator method. The application can use the object to obtain the location of any other document handler event in the XML source document.
The results returned by the object are valid only during the scope of each document handler method; the application will receive unpredictable results if it attempts to use the locator at any other time.
SAX parsers are not required to supply a locator, but they are very strong encouraged to do so. If the parser supplies a locator, it must do so before reporting any other document events. If no locator has been set by the time the application receives the startDocument event, the application should assume that a locator is not available.
This specification extends the Java org.xml.sax.Locator with the following methods:
void destroy ();
The destroy method is required so that SAXParseException implementations can destroy the Locator object that they may have.