File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
The moose likes JDBC and Relational Databases and the fly likes Something wrong in returning ResultSet Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login
JavaRanch » Java Forums » Databases » JDBC and Relational Databases
Bookmark "Something wrong in returning ResultSet" Watch "Something wrong in returning ResultSet" New topic

Something wrong in returning ResultSet

Gorakshanath Pandey

Joined: Feb 25, 2004
Posts: 11
static ResultSet Query(String sql,Connection conn) throws Exception
Statement stmt = conn.createStatement();
ResultSet temprs;
return temprs;

Whats wrong while return ResultSet from a function.?
Blake Minghelli
Ranch Hand

Joined: Sep 13, 2002
Posts: 331
Can you describe the error you are getting? I'm assuming you are getting some kind of an SQLException, but we'll need to know in order to diagnose the problem.

Blake Minghelli<br />SCWCD<br /> <br />"I'd put a quote here but I'm a non-conformist"
Wayne L Johnson
Ranch Hand

Joined: Sep 03, 2003
Posts: 399
The biggest problem is that it becomes very difficult to clean up your resources. There are two separate issues.
First, you have to make sure that every place where this method is called, once the ResultSet is fully processed, that "close()" is called. If you are writing all of the code that access this method, then you have control over that. If you allow other people access to this method, you have to hope that they call "close()", but you have no direct control over it.
Second, even if you manage to call "close()" on every ResultSet that gets returned, how do you close the Statement (stmt)? Your "stmt" variable goes out of scope once the method returns, and so Java can do a little garbage collecting since there are no references to it, but there is no way you can call "close()" on it. So the database can/may/will have resources tied up that are never freed.
So it's a bad idea to do this.
I agree. Here's the link:
subject: Something wrong in returning ResultSet
It's not a secret anymore!