So if you want to share a database connection over multiple queries, in practice you will generally need to do the following:. Reese, G. If you enjoy this Java programming article, please share with friends and colleagues. Follow the author on Twitter for the latest news and rants. Follow BitterCoffey. Editorial page content written by Neil Coffey. All rights reserved. Toggle navigation Javamex: Java Tutorials. Math class Methods of the java.
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Random Using java. Random How does java. I googled and found some links that say it should be closed but then there are people that say the statement and resultset should be assumed to be closed by closing the connection. Not the most popular answer but It seems like some other drivers already do that MySQL and having PG implement this feature would be really neat, as that would facilitate just using try-with-resources on the Connection object itself and have it clean up everything con, stmt, rs once that block of code is done.
No such language exists for the connection. JDBC resources can mean anything. I'm curious why is this even an issue? So I think this particular issue is a genuine bug. To answer your question, as to why, first I thought it was required for the connection to close the stmt and rs so I thought it was a bug. From a certain point of view, one could think that whatever resources are closed in the pg implementation of resultset are "JDBC resources" and therefore should be closed.
But let's say it's not required, then I would like to change the connection issue to a suggestion. It would make the code less verbose and more elegant, in my opinion. And it would also duplicate the behavior in other drivers which I think provides a convenience. It's sort of actually closed internally. We set it to null in the statement. The object is invalid but the state is "open" I have a PR to fix it see above. Skip to content. Star 1k. No you are not required to close anything BUT the connection.
Per JDBC specs closing any higher object will automatically close lower objects. Closing Connection will close any Statement s that connection has created.
Closing any Statement will close all ResultSet s that were created by that Statement. Doesn't matter if Connection is poolable or not. Even poolable connection has to clean before returning to the pool. Of course you might have long nested loops on the Connection creating lots of statements, then closing them is appropriate. Otherwise pooling looses its sense.
I can use the Oneliner on all Queries, even if i do not have a resultSet. This is what my finally block looks like. With Java 6 form I think is better to check it is closed or not before close for example if some connection pooler evict the connection in other thread - for example some network problem - the statement and resultset state can be come closed.
My pattern is for that in older Java syntax is:. In the worst case you will get a warning in long. We are using this pattern in production with an "avarage" load simultanous user and we had no problem with it - so never see that warning message.
That means they are closed automatically upon being destroyed or going out of scope. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Ask Question. Asked 10 years, 10 months ago. Active 1 year, 5 months ago.
Viewed k times. Improve this question. Zeemee Zeemee 9, 12 12 gold badges 48 48 silver badges 76 76 bronze badges. Add a comment. Active Oldest Votes. What you have done is perfect and very good practice. So you can't always count on connection.
I hope this helps :. Improve this answer. Paul Paul 4, 3 3 gold badges 27 27 silver badges 38 38 bronze badges. I agree that it is good practice to close result sets and statements. However, the result sets and statements are garbage collected - they don't stay open forever and you don't "run into many different new problems". Ralph Stevens - You cannot count on that.
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