Managed Connection Pools
mastrivens Jul 13, 2006 7:12 PMI am getting the 'NoManagedConnections' Exception this only happens after a while, but I confess I am confused by the JBoss documentation and the few examples of servlets working with JBoss don't seem to be much help.
I get a new connection object when I call the init method of each of my servlets (there are about 20), that is the only connection object I use for that servlet (I pass it as a parameter to the various factory classes I use within the servlet to do database access).
But if I understand correctly, there is only one instance of each servlet - so it shoud only be using one connection? So I should only be using the same number of connections as servlets?
Do I really need to close and create connections whenever I use JDBC?
Is there somewhere I can put a close command that wouldn't be too much rework? Or is there a timeout for spotting dead connections?
I already have a fairly large application and this would be painful to put it mildly... I thought that was the point of a managed connection pool? I have included the datasource XML file and also the code for getting a connection.
Thank-you in advance
Mark
I have project-ds.xml file to set-up a connection pool with Postgres:
<datasources> <local-tx-datasource> <jndi-name>MtrdbDS</jndi-name> <connection-url>jdbc:postgresql://myserver:5434/myDb</connection-url> <driver-class>org.postgresql.Driver</driver-class> <user-name>someUser</user-name> <password>somepassword</password> <metadata> <type-mapping>PostgreSQL 8.0</type-mapping> </metadata> </local-tx-datasource>
I use a JNDI call to get a connection from that pool:
public Connection getConnection() throws SQLException { Connection conn = null; Context ctx = null; DataSource ds = null; String sourceName = ""; try { ctx = new InitialContext(); if(ctx == null ) throw new NamingException("Error 'Db.getConnection' - No Context"); sourceName = this.getDbName(ctx); ds = (DataSource)ctx.lookup(sourceName); } catch (NamingException e) { MtrErr.writeExc(MtrErr.OTHER_SOURCE,this.getClass().toString(),"getConnection",e); } catch (Exception e) { MtrErr.writeExc(MtrErr.OTHER_SOURCE,this.getClass().toString(),"getConnection",e); } if (ds != null) { conn = ds.getConnection(); } return(conn); }