try-with-resource vs ordinary code with explicit close()-call

Asked Feb 20 '20 at 09:16

Active Feb 20 '20 at 09:27

Viewed 34 times

I have a connection-object which implements java.io.Closeable and I make use of try-with-resource:

version 1:

public List<User> findUsers(Query query) {
    try (this.connection) {
        return conn.find(query);
    }
    // no catch block defined
}

All works, however I am wondering what is the difference in terms of behaviour (for example, exceptions,..) between version 1 and 2:

version 2:

public List<User> findUsers(Query query) {
     var users = this.connection.find(query);
     this.connection.close();
     return users;
}

edited Feb 20 '20 at 09:27

asked Feb 20 '20 at 09:16

nimo23

where is the exception handling code in version 2? – jhamon Feb 20 '20 at 09:18
I does not handle any exception. – nimo23 Feb 20 '20 at 09:18
that's the point – jhamon Feb 20 '20 at 09:18
The difference is that version 2 needs exception handling, and it's a lot of unnecessary boilerplate code – Amongalen Feb 20 '20 at 09:19
4

If an exception is thrown by `find(query)` in version 2, `close()` will not be called. – khelwood Feb 20 '20 at 09:19
2

Does this answer your question? [Try With Resources vs Try-Catch](https://stackoverflow.com/questions/26516020/try-with-resources-vs-try-catch) – jhamon Feb 20 '20 at 09:19
@jhamon yes, thanks, so I will use **version 1**. – nimo23 Feb 20 '20 at 09:23
I changed the **version 1** by using `try(this.connection)` instead of `try(var conn = this.connection)`. I think, it's the same. – nimo23 Feb 20 '20 at 09:28
The difference is that the 2nd version does not have a try... catch (as in the example [here](https://stackoverflow.com/questions/26516020/try-with-resources-vs-try-catch)) therefore there is no grantee the close will happen. – Danny Varod Feb 20 '20 at 10:44

0 Answers0