Try-with-resources and return statements in java

java return try-with-resources
maff picture maff · Apr 8, 2014 · Viewed 14k times · Source

I'm wondering if putting a return statement inside a try-with-resources block prevents the resource to be automatically closed.

try(Connection conn = ...) {
    return conn.createStatement().execute("...");
}

If I write something like this will the Connection be closed? In the Oracle documentation it is stated that:

The try-with-resources statement ensures that each resource is closed at the end of the statement.

What happens if the end of the statement is never reached because of a return statement?

Answer

merlin2011 picture merlin2011 · Apr 8, 2014

Based on Oracle's tutorial, "[the resource] will be closed regardless of whether the try statement completes normally or abruptly". It defines abruptly as from an exception.

Returning inside the try is an example of abrupt completion, as defined by JLS 14.1.

Related questions

Does a finally block always get executed in Java?

Considering this code, can I be absolutely sure that the finally block always executes, no matter what something() is? try { something(); return success; } catch (Exception e) { return failure; } finally { System.out.println("I don't know if this will get printed …

Read More
How to return multiple objects from a Java method?

I want to return two objects from a Java method and was wondering what could be a good way of doing so? The possible ways I can think of are: return a HashMap (since the two Objects are related) or …

Read More
Return a value from AsyncTask in Android

One simple question: is it possible to return a value in AsyncTask? //AsyncTask is a member class private class MyTask extends AsyncTask<Void, Void, Void>{ protected Void doInBackground(Void... params) { //do stuff return null; } @Override protected void onPostExecute(…

Read More