To provide customized error handling, implement this interface and use the setErrorListener method to register an instance of the implmentation with the Transformer. The Transformer then reports all errors and warnings through this interface.

If an application does not register its own custom ErrorListener, the default ErrorListener is used which reports all warnings and errors to System.err and does not throw any Exceptions. Applications are strongly encouraged to register and use ErrorListeners that insure proper behavior for warnings and errors.

For transformation errors, a Transformer must use this interface instead of throwing an Exception: it is up to the application to decide whether to throw an Exception for different types of errors and warnings. Note however that the Transformer is not required to continue with the transformation after a call to ErrorListener.fatalError(TransformerException exception).

Transformers may use this mechanism to report XML parsing errors as well as transformation errors.