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https://issues.apache.org/jira/browse/IGNITE-18049?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17636653#comment-17636653
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Roman Puchkovskiy commented on IGNITE-18049:
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Thanks!
> Cursor#close() should not declare any exceptions in throws clause
> -----------------------------------------------------------------
>
> Key: IGNITE-18049
> URL: https://issues.apache.org/jira/browse/IGNITE-18049
> Project: Ignite
> Issue Type: Improvement
> Reporter: Roman Puchkovskiy
> Assignee: Roman Puchkovskiy
> Priority: Major
> Labels: ignite-3, tech-debt
> Fix For: 3.0.0-beta2
>
> Time Spent: 1h
> Remaining Estimate: 0h
>
> When an {{AutoCloseable}} subinterface/implementation declares {{throws
> Exception}} in its {{close()}} method, it makes it very inconvenient to work
> with such a type using try-with-resources because the using code must use
> something like {{catch (Exception e)}} which makes it difficult to process
> exceptions that might arise in the {{try}} block.
> The suggestion is to make {{Cursor#close()}} not declare any checked
> exceptions. Most of the current implementations of {{Cursor}} already obey to
> this restriction, and a few that don't can be easily reworked to obey.
> The only problem is adapters (when we adapt an {{Iterator}} producing a
> {{{}Cursor{}}}). Here, we must be prepared to get an {{Iterator}} that is a
> resource itself (is an {{{}AutoCloseable{}}}) and hence needs to be closed
> when the cursor is closed. But {{AutoCloseable#close()}} might throw a
> checked exception. It is unacceptable to swallow it, and it is not too good
> to just automatically wrap it in an unchecked exception.
> # The best thing is that developers (who know their resources) write their
> own custom {{Cursor}} implementations handling the closure.
> # We also need a way to adapt 'safe close' iterators (obtained from
> in-memory collections, for example). We should add a method like
> {{Cursor#fromPurIterator(Iterator)}} that will check (at the moment of
> invocation that the provided iterator is NOT an AutoCloseable and will throw
> if it is)
> # We can also provide a generic way to adapt a closeable iterator with a
> method like {{<IT extends Iterator<T> & AutoCloseable>
> Cursor#fromCloseableIterator(IT iterator)}} adding a Javadoc urging the user
> to use this method only when absolutely necessary
> # We probably should not add an omnivorous method that could adapt both pure
> and closeable iterators for now to prevent abuses.
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