MongoTemplate.CloseableIterableCursorAdapter does not null check return values from PersistenceExceptionTranslator. [DATAMONGO-1276]

[spring-projects-issues]

Kristoffer Peterhänsel opened DATAMONGO-1276 and commented

Using the Stream support in a MongoRepository I suddenly started getting exceptions like these:

java.lang.NullPointerException: null
	at org.springframework.data.mongodb.core.MongoTemplate$CloseableIterableCusorAdapter.next(MongoTemplate.java:2389)
	at java.util.Iterator.forEachRemaining(Iterator.java:116)
	at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
	at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:512)
	at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:502)
	at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
	at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
...

After a bit if investigation it turns out that due to some domain model changes I appear to be getting an org.springframework.data.mapping.model.MappingException in the data mapping and since MongoExceptionTranslator does not specifically know about it. So it just returns null.

That appears to be fine according to the PersistenceExceptionTranslator interface. But it appears that the Spring Data MongoDB code will often throw the result without any null checks. Provoking an NPE and hiding the actual reason for the exception

---

Affects: 1.7.2 (Fowler SR2)

Issue Links:

• DATAMONGO-1295 The MongoTemplate.CloseableIterableCusorAdapter runs into an NPE when a MappingException was raised
  ("is duplicated by")
• DATAMONGO-1307 Stop converting user-defined runtime exceptions to NPEs
  ("is duplicated by")

Backported to: 1.8.1 (Gosling SR1), 1.7.3 (Fowler SR3)

[spring-projects-issues]

Oliver Drotbohm commented

Can you elaborate on this? (feels like theres a verb missing)

After a bit if investigation it turns out that due to some domain model changes org.springframework.data.mapping.model.MappingException and that MongoExceptionTranslator does not specifically know about it.

Do you have a sample project that shows the issue? Looks like something is calling next() after close() has been called (as the latter is the only place that persistenceExceptionTranslator becomes null

[spring-projects-issues]

Kristoffer Peterhänsel commented

Woops. Yeah the text was a bit garbled. Should be fixed now

I'm not quite sure how I would go about making a easily runnable sample project that consistently throws an exception that would provoke it.

But yeah it is specifically a problem that the CloseableIterableCusorAdapter does not handle null returns from the called PersistenceExceptionTranslator (since it is allowed by the API)

[spring-projects-issues]

Oliver Drotbohm commented

That should be fixed. Feel free to give the snapshots a spin