Closing a Query
When you are finished with the result of a query, you can close
the results, allowing the release of resources used in implementing the
query (e.g., database cursors or iterators). You can use the following
Query
methods to close query
results:
void close(Object queryResult); void closeAll( );
The close( )
method closes the
result that was returned by one call to execute( )
. You use
closeAll( )
to close all the results
from calls to execute( )
on the
Query
instance. Both methods release
the query result’s resources. After they complete, you cannot use the
query result (e.g., to iterate the returned elements). Closing a query
result does not affect the state of its instances. Once you have closed
a result, any Iterator
that was
acquired returns false
to hasNext( )
and throws NoSuchElementException
if next( )
is called. But
the Query
instance is still valid and
can be used to execute more queries. Each query example in this chapter
closed its query result.
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