[
https://issues.apache.org/jira/browse/DRILL-5169?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15786120#comment-15786120
]
Julian Hyde commented on DRILL-5169:
------------------------------------
I think {{DrillCloseable}} should extend {{AutoCloseable}}. You can override
the {{close}} method to have no declared exceptions.
People can then close a {{DrillCloseable}} from within try-with-resources if
they like. And you can use utilities such as [Guava's
Closer|https://google.github.io/guava/releases/19.0/api/docs/com/google/common/io/Closer.html]
or [Calcite's
Closer|https://github.com/apache/calcite/blob/master/core/src/main/java/org/apache/calcite/util/Closer.java].
> Reconsider use of AutoCloseable within Drill
> --------------------------------------------
>
> Key: DRILL-5169
> URL: https://issues.apache.org/jira/browse/DRILL-5169
> Project: Apache Drill
> Issue Type: Improvement
> Affects Versions: 1.8.0
> Reporter: Paul Rogers
> Priority: Minor
>
> Drill has many resources that must be closed: value vectors, threads,
> operators and on and on. The {{close()}} method may sometimes throw an
> exception or take a long time. Drill has developed, or borrowed from Guava,
> many utilities to help manage the close operation.
> Java has two forms of "predefined" closeable interfaces: {{Closeable}} and
> {{AutoCloseable}}. {{Closeable}} is for I/O resources and thus can throw an
> {{IOException}}. {{AutoCloseable}} throws no exception, and is integrated
> into the language for use in try-with-resources blocks. Because
> {{AutoCloseable}} is intended only for this use, any creation or return of an
> {{AutoCloseable}} outside of a try-with-resources block produces compiler
> warnings.
> Neither of the two Java interfaces fit Drill's needs. {{Closeable}} throws a
> particular exception ({{IOException}}) which Drill seldom throws, but does
> not throw exceptions that Drill does throw.
> Drill has settled on {{AutoCloseable}}, but few of Drill's resources are
> limited in life to a single try-with-resources block. The result is either
> hundreds of resource warnings (which developers learn to ignore), or hundreds
> of insertions of {{@SuppressWarnings("resource")}} tags, which just clutter
> the code.
> Note that there is nothing special about either of the Java-provided
> interfaces. {{Closeable}} is simply a convention to allow easy closing of IO
> resources such as streams and so on. {{AutoCloseable}} exists for the sole
> purpose of implementing try-with-resource blocks.
> What we need is a Drill-specific interface that provides a common {{close()}}
> method which throws only unchecked exceptions, but is not required to be used
> in try-with-resources. Perhaps call this {{DrillCloseable}}.
> Next, reimplement the various close utilities. For example:
> {{DrillCloseables.closeAll()}} would close a set of resources, suppressing
> exceptions, and throwing a single combined exception if any operations fail.
> Then, convert all uses of {{AutoCloseable}} to {{DrillCloseable}}, or at
> least all that are not used in try-with-resources block. Doing so will
> eliminate many compiler warnings and or suppress warnings tags. Because Java
> allows classes to implement multiple interfaces, it is even possible for a
> class to implement both {{DrillCloseable}} and {{AutoCloseable}} in the rare
> instance where both are needed.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
