topic Re: Weird NullPointerException in tMap in Talend Studio

Weird NullPointerException in tMap

Anonymous — Wed, 03 Oct 2018 05:22:49 GMT

Hi there,

I'm getting a NullPointerException when trying to calculate an expression in a tMap that has 2 inputs.

Here is the syntax of the expression:

Relational.ISNULL(account_transaction.date_entree) || Relational.ISNULL(account_transaction.date_sortie)
	? null
	: TalendDate.diffDate(account_transaction.date_sortie, account_transaction.date_entree, "HH") <= 5
		? 0.0
		: Relational.ISNULL(calcul_taxe_sejour.taxe_sejour)
			? null
			: calcul_taxe_sejour.taxe_sejour

account_transaction is my Main and calcul_taxe_sejour is my Lookup.

The error is raised on this line of the expression:

		: Relational.ISNULL(calcul_taxe_sejour.taxe_sejour)

but everything is correctly written for the Lookup flow and moreover the job compiles:

Also I set up the field as nullable.

I don't understand what the problem is. If anyone can suggest a few things I can try to debug that would be awesome.

Thx!

Re: Weird NullPointerException in tMap

fdenis — Wed, 03 Oct 2018 08:48:13 GMT

1: I m used to write like (condition)?true:false when there is more than one condition
2: why dont you use calcul_taxe_sejour.taxe_sejour!=null
3: is calcul_taxe_sejour != null
Regards

Re: Weird NullPointerException in tMap

Anonymous — Wed, 03 Oct 2018 08:58:28 GMT

Can you please elaborate the entire tmap configuation with a screenshot ?

Thanks ,

Praveen M.

Re: Weird NullPointerException in tMap

Anonymous — Wed, 03 Oct 2018 09:14:37 GMT

I suspect your issue is that the column you are passing the data to is not nullable. Your code looks OK, but it will enable a null output. In your output schema, check that the column is nullable.

Re: Weird NullPointerException in tMap

Anonymous — Wed, 03 Oct 2018 09:39:05 GMT

1: You mean group everything under 1 condition? But then how do you manage multiple output values (here I can have null, 0.0 or a field value)?
2: I've always used Relational.ISNULL, but I don't remember where I learnt that Anyway I tested and it's giving the same error.
3: Not sure what you mean here, calcul_taxe_sejour can be null which is why I'm trying to handle it.

Re: Weird NullPointerException in tMap

Anonymous — Wed, 03 Oct 2018 09:39:42 GMT

I added 2 screenshots with the tMap configuration

Re: Weird NullPointerException in tMap

Anonymous — Wed, 03 Oct 2018 09:40:28 GMT

Nope I mentioned this, this is the first thing I checked but all the fields in the tMap output are nullable 😕

Re: Weird NullPointerException in tMap

fdenis — Wed, 03 Oct 2018 09:50:42 GMT

remove the identified wrong part of the condition then run to retrive all data used into this condition.
does it work?
did you have null values?
did you have blanc values?

Re: Weird NullPointerException in tMap

Anonymous — Wed, 03 Oct 2018 09:57:37 GMT

I suspect that the error line is misleading here. Take a look at this mini tutorial (https://community.talend.com/t5/How-Tos-and-Best-Practices/How-to-debug-tMap-errors/m-p/40951#M9) on debugging tMap errors. This is a useful and relatively easy way of trapping issues like this.

Re: Weird NullPointerException in tMap

Anonymous — Wed, 03 Oct 2018 10:50:30 GMT

OK so I just replaced the "null" in the last nested if with a numeric value and it works:

Relational.ISNULL(account_transaction.date_entree) || Relational.ISNULL(account_transaction.date_sortie)
	? null
	: TalendDate.diffDate(account_transaction.date_sortie, account_transaction.date_entree, "HH") <= 5
		? 0.0
		: Relational.ISNULL(calcul_taxe_sejour.taxe_sejour)
			? -1.0
			: calcul_taxe_sejour.taxe_sejour

Even if the output column is set as nullable since the beginning.

Now comes another question: how come the "null" in the first "if" does not trigger the same error? I checked and there are rows that satisfy the first condition and these were set to null...

Re: Weird NullPointerException in tMap

fdenis — Wed, 03 Oct 2018 10:59:26 GMT

if trouble is on output you may cast your result even if null.

(Relational.ISNULL(account_transaction.date_entree) || Relational.ISNULL(account_transaction.date_sortie)
? (Integer)null
: TalendDate.diffDate(account_transaction.date_sortie, account_transaction.date_entree, "HH") <= 5
? 0.0
: Relational.ISNULL(calcul_taxe_sejour.taxe_sejour)
? (Integer)null
: calcul_taxe_sejour.taxe_sejour )

Re: Weird NullPointerException in tMap

Anonymous — Wed, 03 Oct 2018 12:12:37 GMT

Can you show us your output schema? Either your column is not set to nullable or there is a bug