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https://issues.apache.org/jira/browse/COMMONSRDF-35?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15553656#comment-15553656
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ASF GitHub Bot commented on COMMONSRDF-35:
------------------------------------------
Github user stain commented on the issue:
https://github.com/apache/incubator-commonsrdf/pull/24
In order to close the `RepositoryConnection` (and `RepositoryResult`) I
added an interface
``` java
public interface ClosableIterable<T> extends java.util.Iterable<T>,
AutoCloseable { }
```
which is not very different from RDF4J's
`org.eclipse.rdf4j.common.iteration.CloseableIteration` and
`CloseableIterationIterator`; but can be used like this:
```java
RDF4JGraph graph; // ..
try (ClosableIterable<Triple> triples : graph.iterate()) {
for (Triple t : triples) {
return t; // OK to terminate for-loop early
}
}
```
It will then close both the `RepositoryResult` and `RepositoryConnection`.
It also closes on the last `.hasNext()` - but that is for convenience only
for interoperability with `Graph.iterate()` interface, and would not happen if
you break out of the for loop return early (as above).
The only other alternatives to provide a somewhat transparent .iterate()
with RDF4J (without the caller having to do say `.begin()` and `.end()`) I can
think of would be either a `.finalize()` in the Iterator (but you won't know
if/when it will run) and to consume the whole of the iteration in memory and
expose a normal java.util.List iterator (which would consume lots of memory and
fall over after 2G entries).
Of course interoperability is already somewhat broken with my proposal here
as the other `Graph.iterate()` are not (now) ClosableIterable and thus can't be
used with the try-with-resources block like that.
I updated `org.apache.commons.rdf.api.AbstractGraphTest` to avoid the RDF4J
tests taking a long time (20s timeout pr test if the repository has unclosed
connections). For the `.stream()` this was easy (`Stream` implements
`AutoClosable`), but for the `Iterable` I had to do:
```java
private void closeIterable(Iterable<Triple> iterate) throws Exception {
if (iterate instanceof AutoCloseable) {
((AutoCloseable) iterate).close();
}
}
```
> rdf4j integration
> -----------------
>
> Key: COMMONSRDF-35
> URL: https://issues.apache.org/jira/browse/COMMONSRDF-35
> Project: Apache Commons RDF
> Issue Type: New Feature
> Reporter: Stian Soiland-Reyes
> Assignee: Stian Soiland-Reyes
> Labels: integration, rdf4j, sesame
> Fix For: 0.3.0
>
>
> Add a new rdf4j module with implementation for Eclipse rdf4j
> See https://github.com/apache/incubator-commonsrdf/tree/rdf4j/rdf4j
> A legacy sesame branch could then be added by mainly copy/paste and change
> the import
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