bad "count" string queries throw mysterious NullPointerException [DATACOUCH-617]

[spring-projects-issues]

Michael Reiche opened DATACOUCH-617 and commented

If a 'count' query does not return anything, a mysterious NPE is thrown.

   @Query("SELECT 1 FROM `#{#n1ql.bucket}` WHERE nothing = `matches`)
Long count();

 

java.lang.NullPointerExceptionjava.lang.NullPointerException at org.springframework.data.couchbase.core.ExecutableFindByQueryOperationSupport$ExecutableFindByQuerySupport.count(ExecutableFindByQueryOperationSupport.java:90) at org.springframework.data.couchbase.repository.query.N1qlRepositoryQueryExecutor.execute(N1qlRepositoryQueryExecutor.java:70) at org.springframework.data.couchbase.repository.query.CouchbaseRepositoryQuery.execute(CouchbaseRepositoryQuery.java:42)

Adding a check for null would prevent the NPE, but silently ignoring that the query was erroneous is not a good solution.

	@Override
	public long count() {
		Long l =  reactiveSupport.count().block();
		return l != null ? l.longValue() : 0;
	}

 
Another possibility is changing the return type of the count() method to Long, so that it could actually be null.

Another possibility is explicitly throwing an exception if the return values is null.

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No further details from DATACOUCH-617