topic NullPointerException when native query with null result in Alfresco Archive

NullPointerException when native query with null result

lotzy — Tue, 01 Oct 2013 15:05:59 GMT

Hi there,We need to find out the last executed process with a given name so we used this piece of code:NativeHistoricProcessInstanceQuery haiq = historyService.createNativeHistoricProcessInstanceQuery();HistoricProcessInstance processNative = haiq.sql("SELECT MAX(id_) AS id FROM act_hi_procinst WHER

Re: NullPointerException when native query with null result

martin_grofcik — Wed, 02 Oct 2013 04:44:43 GMT

Hi.

I have implemented small jUnit test (https://github.com/martin-grofcik/Activiti/commit/b311ba6c8729633c17df1d33ad42288b9ac386ee)
<code>
    @Deployment(resources = {"org/activiti/engine/test/history/oneTaskProcess.bpmn20.xml"})
    public void testNativeHistoricProcessInstanceQuery() {
        NativeHistoricProcessInstanceQuery haiq = historyService.createNativeHistoricProcessInstanceQuery();
        HistoricProcessInstance processNative = haiq.sql("SELECT MAX(id_) AS id FROM act_hi_procinst WHERE business_key_ = 'DOES_NOT_EXIST'").singleResult();
        assertEquals(null, processNative);
    }
</code>

It passes. May be I did something wrong.

Question
Could you create jUnit test for it?

Idea
Can you query DB to get rows count before SELECT MAX(id_) ? (I know it is overhead.)

Re: NullPointerException when native query with null result

lotzy — Thu, 03 Oct 2013 09:29:57 GMT

Thanks a lot Martin, for your fast response. We ran the JUnit test with our Activiti version 5.12.1 and we got the same NullPointerException, then we upgraded to version 5.13 and we did NOT encounter the error. So this bug is resolved in the latest version of Activiti. Case closed.

Thank you again.