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Is connection.close(); enough?

Richard Bell

Joined: Oct 20, 2011
Posts: 4

When using a data source to access a database is "connection.close();" going to close the associated statement and resultSet?

I have read a number of articles posted on a number of sites,
almost all agree that it is good practice to close the resultSet, statement and connection individually.
I have also read that the JDBC specification details that closing the connection will also close any associated resources (resultSet and statements).
There does not seem to be a right or wrong answer.

So would code closing just the connection be appropriate or should we always close all three?
Rob Spoor

Joined: Oct 27, 2005
Posts: 20276

Closing the connection will close the (prepared / callable) statements and result sets. However, depending on the application, there may be a long time between no longer needing the statements and result sets and closing the connection. All this time, these resources will still be active. This can lead to a huge memory leak (especially with larger result sets) and failure to create statements later if the maximum number is reached. So yeah, close everything as soon as you're done with them. Preferably, use try-with-resources:
Likewise for ResultSet. You can even combine the two:

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