How-to: Handle errors and customize the OAuth 2.0 Error response

[jgrandja]

Publish a guide on How-to: Handle errors and customize the OAuth 2.0 Error response

Related gh-499

[jgrandja]

Sample demonstrating how to customize the error response parameters using OAuth2ErrorAuthenticationFailureHandler:

private AuthenticationFailureHandler authenticationFailureHandler = createAuthenticationFailureHandler();

private static AuthenticationFailureHandler createAuthenticationFailureHandler() {
	OAuth2ErrorHttpMessageConverter errorResponseConverter = new OAuth2ErrorHttpMessageConverter();
	errorResponseConverter.setErrorParametersConverter(error -> {
		Map<String, String> parameters = new HashMap<>();
		// Only return the error code
		parameters.put(OAuth2ParameterNames.ERROR, error.getErrorCode());
		return parameters;
	});

	OAuth2ErrorAuthenticationFailureHandler authenticationFailureHandler = new OAuth2ErrorAuthenticationFailureHandler();
	authenticationFailureHandler.setErrorResponseConverter(errorResponseConverter);

	return authenticationFailureHandler;
}

[jgrandja]

Sample demonstrating how to customize the HTTP status for the error response using OAuth2ErrorAuthenticationFailureHandler:

private AuthenticationFailureHandler authenticationFailureHandler = createAuthenticationFailureHandler();

private static AuthenticationFailureHandler createAuthenticationFailureHandler() {
	OAuth2ErrorHttpMessageConverter errorResponseConverter = new OAuth2ErrorHttpMessageConverter() {
		@Override
		protected void writeInternal(OAuth2Error error, HttpOutputMessage outputMessage)
				throws HttpMessageNotWritableException {

			HttpServletResponse servletResponse = ((ServletServerHttpResponse) outputMessage).getServletResponse();
			if (OAuth2ErrorCodes.INVALID_CLIENT.equals(error.getErrorCode())) {
				servletResponse.setStatus(HttpStatus.UNAUTHORIZED.value());
			} else {
				servletResponse.setStatus(HttpStatus.BAD_REQUEST.value());
			}
			super.writeInternal(error, outputMessage);
		}

	};

	OAuth2ErrorAuthenticationFailureHandler authenticationFailureHandler = new OAuth2ErrorAuthenticationFailureHandler();
	authenticationFailureHandler.setErrorResponseConverter(errorResponseConverter);

	return authenticationFailureHandler;
}