很少的JDBC连接

Question

As I know connection is kind of very expensive operation. Which approach should I follow to handle few connections? I have seen a lots of examples where author talks about only one connection or uses connection pool(from JBoss or something). My code looks like this:

1) make new connection

2) do some logic

3) close connection

DriverManager.registerDriver(new net.sourceforge.jtds.jdbc.Driver());    
con = DriverManager.getConnection(URL, username, password);  
if(con!=null) 
   System.out.println("Connection Successful !\n");  
//logic      
if(con!=null)
   con.close();

But I've got few similar methods based on this approach. So do I really have to make new connection or should I use the only one? If I use one connection, do I need to close it after?

PS. App is not a servlet.

Answer 1

You can use a connection pool like http://sourceforge.net/projects/c3p0/ or http://jolbox.com/ to abstract from this problem.

If you do not close connections after use, you will have lots of opening connections that are not in use (until database cleans up).