Exception swallowed in "AndFieldValueGenerator"

In AndFieldValueGenerator, in the function

protected List<Integer> generateCandidatesNotIncludingIntervalExtremes(int start, int end)

there is a try/catch which just logs the exception and returns an empty list.

Catched expected exception while generating candidates
com.cronutils.model.time.generator.NoSuchValueException: null
	at com.cronutils.model.time.generator.AndFieldValueGenerator.generateNextValue(AndFieldValueGenerator.java:52)
	at com.cronutils.model.time.generator.AndFieldValueGenerator.generateCandidatesNotIncludingIntervalExtremes(AndFieldValueGenerator.java:84)
	at com.cronutils.model.time.generator.FieldValueGenerator.generateCandidates(FieldValueGenerator.java:61)
	at com.cronutils.model.time.ExecutionTimeBuilder.forHoursMatching(ExecutionTimeBuilder.java:64)
	at com.cronutils.model.time.ExecutionTime.forCron(ExecutionTime.java:53)

So I have a situation where a client generates cron expressions interactively using the parser, and expressions which are “valid” then generate completely unexpected results when used with the ExecutionTime class.

The exception is printed, but there is no way to guard against this behaviour because the exception is not propagated.

An example expression is 0 0 0-07,17-0 ? * SAT which is parsed as every hour between 0 and 7 and every hour between 17 and 0 at Saturday day.

If this is expression is not usable, it should not be accepted by the parser. If that’s too hard, at least when an ExecutionTime is created using a Cron which it can’t use, an exception should be generated so it is possible to validate against that, and keep junk out of the system.

[jmrozanec]

@jamescosford glad to hear that! That things moved on and the exception no longer appears, as well that you sent a PR 😄 Thanks! We will merge soon. Best!

[jmrozanec]

@IndeedSi thank you for the insight!