in src/main/java/org/apache/nifi/processor/util/StandardValidators.java [442:455]
public ValidationResult validate(final String subject, final String input, final ValidationContext context) {
if (context.isExpressionLanguageSupported(subject) && context.isExpressionLanguagePresent(input)) {
try {
final String result = context.newExpressionLanguageCompiler().validateExpression(input, true);
if (!isEmpty(result)) {
return new ValidationResult.Builder().subject(subject).input(input).valid(false).explanation(result).build();
}
} catch (final Exception e) {
return new ValidationResult.Builder().subject(subject).input(input).valid(false).explanation(e.getMessage()).build();
}
}
return new ValidationResult.Builder().subject(subject).input(input).valid(true).build();
}