um, you could just use a SQLTemplate to execute that SQL and tell it
to just return data rows. You should not need to actually write jdbc.
-- Joshua T. Pyle Go has always existed.On 11/30/05, Claudio Rosati <claudio.rosat..csys.it> wrote: > Hello Andrus, > > I've following your suggestions but every thing was OK. So I've started > debugging my application with Cayenne sources to better understand the > executed operation, in order to identify the problem. > > After a day I've discovered the previously submitted code was not the > problem's cause, but just an effect of another code executed just before it: > > > public static long getNextRecordCode ( ) > { > > long code = -1; > PreparedStatement ps = null; > ResultSet rs = null; > > try { > > DataContext dc = CayenneUtility.createDataContext(); > Connection con = dc.lookupDataNode( > > dc.getEntityResolver().lookupDbEntity(Record.class).getDataMap() > ).getDataSource().getConnection(); > > ps = con.prepareStatement("SELECT nextval('code_provider')"); > rs = ps.executeQuery(); > > if ( rs.next() ) > code = rs.getLong(1); > > } > catch ( Exception ex ) { > ... > } > finally { > try { > if ( rs != null ) > rs.close(); > } > catch ( Exception ex ) { ... } > try { > if ( ps != null ) > ps.close(); > } > catch ( Exception ex ) { ... } > } > > return code; > > } > > > As you can see, I've not closed the JDBC connection thinking that this could > cause problems to Cayenne. Instead, after debugging through Cayenne code, > I've discovered that the returned connection is a PooledConnectionImpl whose > close() doesn't really close the JDBC connection, but release the connection > to the pool instead. > > So, closing the connection solved the problem. > > Now I would like to suggest the following: > > 1. add notice in the PoolManager.getConnection methods > documentation about the need to call close() in order > to release to connection to the pool; > > 2. same for PooledConnectionImpl documentation; > > 3. add the following method in DataContext (or at least > a corresponding documentation) in order to easily > obtain a JDBC connection from Cayenne > > public Connection getConnection ( Class target ) > throws ... > { > return lookupDataNode( > getEntityResolver().lookupDbEntity(target).getDataMap() > ).getDataSource().getConnection(); > ) > > for the rare situations where handling directly > with JDBC is more convenient (or, maybe, the only > solution) than using Cayenne (e.g. "SELECT count(*) FROM ..."). > > > Claudio > > > ------------------------------------ > Advanced Computer Systems S.p.A. > Claudio Rosati > Project Manager > claudio.rosat..csys.it > via Della Bufalotta 378 > 00139 Roma, RM > Italy > tel: +39 06 8709 0516 > fax: +39 06 8720 1502 > ------------------------------------ > > > > -----Messaggio originale----- > > Da: Andrus Adamchik [mailto:andru..bjectstyle.org] > > Inviato: luned́ 28 novembre 2005 21.50 > > A: cayenne-use..bjectstyle.org > > Oggetto: Re: [v.1.1.3 September 28 2005] Global exception. > > > > I am fairly certain that 1.1.3 Cayenne connection pool > > doesn't leak by itself, as this would've been a common > > problem for everybody. So try to determine whether the leak > > can occur somewhere in your application. A few things to check: > > > > (1) do you have queries that run longer than 0-10 seconds? > > (you can check the logs - Cayenne prints JDBC timing) > > > > (2) do you use Cayenne ResultIterator, if so do you close it properly? > > > > (3) Also it might help to take a thread dump of the > > application when the error starts to happen to see if there > > are deadlocks: > > > > http://java.sun.com/developer/technicalArticles/Programming/St > > acktrace/ > > > > (do "kill -QUIT <pid>" on UNIX or "Ctrl+Break" on Windows) > > > > Hope this helps. > > > > Andrus > > > > > > On Nov 28, 2005, at 7:47 PM, Claudio Rosati wrote: > > > Hello all, > > > > > > I'm using Cayenne 1.1.3 with PostgreSQL 8.1 on Windows XP & Linux. > > > The following code, called in a context where the DataContext > > > __datactx is already set up and possibly some commit were already > > > called, seems consume a JDBC connection when __datactx.performQuery > > > (query); is called without releasing it. > > > > > > private Collocation getCollocation ( String pressmark ) { > > > Collocation collocation = null; > > > Expression exp = ExpressionFactory.matchExp("pressmark", > > pressmark); > > > SelectQuery query = new SelectQuery(Collocation.class, exp); > > > List queriedList = __datactx.performQuery(query); > > > if ( queriedList.size() > 0 ) > > > collocation = (Collocation) queriedList.get(0); > > > return collocation; > > > } > > > Clearly after a while (a very short while) the following > > errors occurs > > > > > > CADMUS Ver 1.3.0 > > > EXCEPTION: Unexpected exception > > > org.objectstyle.cayenne.CayenneRuntimeException. > > > Location is: > > > > > org.objectstyle.cayenne.access.util.SelectObserver.nextGlobalException > > > , line 222. > > > Message is: [v.1.1.3 September 28 2005] Global exception. > > > Stack trace: org.objectstyle.cayenne.CayenneRuntimeException: [v. > > > 1.1.3 September 28 2005] Global exception. > > > at > > > > > org.objectstyle.cayenne.access.util.SelectObserver.nextGlobalException > > > (SelectObserver.java:222) > > > at org.objectstyle.cayenne.access.DataNode.performQueries > > > (DataNode.java:325) > > > at org.objectstyle.cayenne.access.DataDomain.performQueries > > > (DataDomain.java:654) > > > at org.objectstyle.cayenne.access.DataContext.performQueries > > > (DataContext.java:1408) > > > at org.objectstyle.cayenne.access.Transaction.performQueries > > > (Transaction.java:179) > > > at org.objectstyle.cayenne.access.DataContext.performQueries > > > (DataContext.java:1366) > > > at org.objectstyle.cayenne.access.DataContext.performQuery > > > (DataContext.java:1622) > > > at org.objectstyle.cayenne.access.DataContext.performQuery > > > (DataContext.java:1485) > > > at > > > > > it.acsys.multimedia.products.cadmus.plugin.sbn.CollocationImporter.get > > > Collocation(CollocationImporter.java:222) > > > at > > > > > it.acsys.multimedia.products.cadmus.plugin.sbn.CollocationImporter.imp > > > ortCollocations(CollocationImporter.java:101) > > > at > > > > > it.acsys.multimedia.products.cadmus.plugin.sbn.RecordImporter.getCollo > > > cations(RecordImporter.java:798) > > > at > > > > > it.acsys.multimedia.products.cadmus.plugin.sbn.RecordImporter.importRe > > > cord(RecordImporter.java:412) > > > at > > > > > it.acsys.multimedia.products.cadmus.plugin.sbn.RecordImporter.getRecor > > > d(RecordImporter.java:336) > > > at > > > > > it.acsys.multimedia.products.cadmus.plugin.sbn.RecordImporter.importRe > > > cords(RecordImporter.java:168) > > > at > > > > > it.acsys.multimedia.products.cadmus.plugin.sbn.SBNImporter.importRecor > > > ds(SBNImporter.java:305) > > > at > > > > > it.acsys.multimedia.products.cadmus.plugin.sbn.wizard.Progress.importR > > > ecords(Progress.java:208) > > > at > > > it.acsys.multimedia.products.cadmus.plugin.sbn.wizard.Progress.run > > > (Progress.java:228) > > > at it.acsys.swing.wizard.DefaultProgressPage$2.run > > > (DefaultProgressPage.java:1181) > > > at java.lang.Thread.run(Thread.java:595) > > > Caused by: java.sql.SQLException: Can't obtain connection. Request > > > timed out. Total used connections: 20 > > > at > > > org.objectstyle.cayenne.conn.PoolManager.uncheckPooledConnection > > > (PoolManager.java:466) > > > at org.objectstyle.cayenne.conn.PoolManager.getConnection > > > (PoolManager.java:392) > > > at org.objectstyle.cayenne.conn.PoolManager.getConnection > > > (PoolManager.java:385) > > > at org.objectstyle.cayenne.access.DataNode.performQueries > > > (DataNode.java:313) > > > ... 17 more > > > > > > I've tried to give more connection but the problems always > > occurs (in > > > a longer time). > > > > > > I don't understand is I've missed something in the code or > > somewhere > > > in the initialization. > > > > > > Anyone has some suggestions? > > > > > > Thanks > > > > > > Claudio > > > > > > > > > > > > > > > > > > > > > <642113416> > > > Multimedia Division > > > Claudio Rosati > > > Project ManagerAdvanced Computer Systems S.p.A. > > > via Della Bufalotta 378 > > > 00139 Roma, RM > > > Italy > > > claudio.rosat..csys.it > > > tel: > > > fax:+39 06 8709 0516 > > > +39 06 8720 1502 > > > Add me to your address book...Want a signature like this? > > > > > > > > > > >
This archive was generated by hypermail 2.0.0 : Wed Nov 30 2005 - 11:48:34 EST