Why Java throws nullpointerexception?

Question

When i insert values with sql API and handle exceptions and do it again to make sure the "exceptionAlreadyExists" works Eclipse throws me a NullPointerException :( sorry for my english help me please

Answer 1

Well, in the example code you're only catching the PrAlreadyExistException not the NullpointerException, you could try to catch Exception instead.

Answer 2

Sounds like an interesting question but it is impossible to answer without an example code.
Would you mind publishing a minimum working example that shows the error on the code playground and link it here?

Answer 3

Hey, no worries.
What persistence api do you use?
I guess we need to dive deeper into your insert method to understand what's going on. And I'm not sure what the SQL api is.

Looks like the insert returns null because the record could not be created (it does already exist on the second attempt), not sure why the npe wasn't caught though..

Answer 4

Maybe it's a sql problem, sorry i'm a begginer don't judge me
This is only the Main class.
i already builded the connection with sql and created the classes.
also import them.

https://code.sololearn.com/c8SfFj22G98E/?ref=app

Answer 5

Full stacktrace would be more helpful...
And yes, catch everything what could be thrown...

Answer 6

I solved it!
The problem was that i put the boolean if(to prove that already exist) of my created exception in the try/catch and it has to be outside.😅 Before the block.
This was my first problem that i shared with the community.
Thank you so much🥰

Answer 7

Exactly it's something like that.
I use the MySQL JDBC.
I really don't know why my created exception can't catch it.
It's too much code to write here but thanks anyway for your help.