[Java] ArrowVectorIterator incorrectly closes Vectors

[asfimport]

If you’re using the iterator with reuseVectorSchemaRoot set to false, the first n-1 VSRs returned by a call to next() have their resources managed by the client code, but the last one gets closed when the iterator is closed. This is inconsistent and contradicts the  javadoc for next:

• If {@link JdbcToArrowConfig#isReuseVectorSchemaRoot()} is false,

• the client is responsible for freeing its resources.

  The iterator calls close on its CompositeJDBCConsumer instance, which in turn closes the vectors held by each consumer. 

   

  @Override
public void close() {
  if (config.isReuseVectorSchemaRoot()) {
  nextBatch.close();
      }
    compositeConsumer.close();
  ``}

Reporter: Larry White / @lwhite1
Assignee: Larry White / @lwhite1

PRs and other links:

• GitHub Pull Request #14534

_{Note: This issue was originally created as ARROW-18178. Please see the migration documentation for further details.}

[asfimport]

David Li / @lidavidm:
Issue resolved by pull request 14534
#14534