Re: connection pooling with servlets - Mailing list pgsql-jdbc

From J.
Subject Re: connection pooling with servlets
Date
Msg-id 20060428005915.94720.qmail@web54213.mail.yahoo.com
Whole thread Raw
In response to Re: connection pooling with servlets  (Dave Cramer <pg@fastcrypt.com>)
Responses Re: connection pooling with servlets  (David Durham <ddurham@vailsys.com>)
List pgsql-jdbc
Thanks for replying.  I'm not sure if that would help, but maybe if I understand the suggestion better it will.

Right now I've got the index.jsp calling Login servlet via POST.  Then Login creates the connection, puts it into a session with some other attributes and forward(req,res) to welcome.jsp.  Welcome.jsp has a form that uses GET to call a Search servlet and this is where I get a null pointer on the connection object.  I'm trying to get the session out of the request object, but it seems like the request loses state by the time I'm getting to it (in Search servlet).

Dave Cramer <pg@fastcrypt.com> wrote:
Use a static method to get the connection instead of the session.

Dave
On 27-Apr-06, at 8:02 PM, J. wrote:

I am a novice, but thought it would make more sense to post this here.� I'm trying to write a basic webstore app for a school project and I'm having trouble getting more than one servlet to access the database connection.� I tried the method described on the PostgreSQL site - as I understood it.� That entailed opening a connection in one servlet and then having code like this in other servlets that need connections:

��� Connection grabConnection(HttpSession userSession){
��� ��� ds = (Jdbc3PoolingDataSource) userSession.getAttribute("dSource");
��� ��� Connection con = null;

��� ��� try {
��� ��� ��� con = ds.getConnection();
��� ��� ��� // use connection
��� ��� } catch(SQLException e) {
��� ��� ��� // log error
��� ��� } finally {
��� ��� ��� if(con != null) {
��� ��� ��� ��� try {con.close();}catch(SQLException e) {}
��� ��� ��� }
��� ��� }
��� ��� return con;
��� }

The trouble is (I'm sure you see it already) that passing a dataSource object in a session doesn't seem to work.� If I don't have a dataSource, then I can't make a connection and if I try to create a new connection, I get the error that is something like "Connection with that name already exists".� Any help and I'd be gratefull.� Thanks.


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