Tomcat, Struts, and JDBCException

dtam · **Joined:** Tue Jan 06, 2004 4:51 pm **Posts:** 48

Hi,

I'm using the struts plug-in for hibernate 2.1 in Tomcat 5. So far it's worked pretty well, except I'm having this problem:

Code:

ERROR net.sf.hibernate.util.JDBCExceptionReporter --
Could not execute query
org.postgresql.util.PSQLException: Connection is closed.  Operation is not permi
tted.
        at org.postgresql.core.QueryExecutor.executeV3(QueryExecutor.java:116)

I have a general parent object that is inherited by several objects that looks like:

Code:

/*
 * HSObjectManager.java
 *
 * Created on January 9, 2004, 12:48 PM
 */

package com.cc;

import net.sf.hibernate.FetchMode;
import net.sf.hibernate.FlushMode;
import net.sf.hibernate.LockMode;
import net.sf.hibernate.Session;
import net.sf.hibernate.SessionFactory;
import net.sf.hibernate.Transaction;
import net.sf.hibernate.HibernateException;
import net.sf.hibernate.cfg.Configuration;
import net.sf.hibernate.cfg.Environment;
import net.sf.hibernate.expression.Example;
import net.sf.hibernate.expression.Expression;
import net.sf.hibernate.expression.MatchMode;
import net.sf.hibernate.type.Type;

import java.util.Properties;
import java.io.FileInputStream;

import javax.naming.InitialContext;

/**
 * Hibernate-Struts Object Manager, in general. 
 * Meant to be inherited.
 * @author  dtam
 */
public class HSObjectManager {
    
    protected InitialContext ctx = null;
    protected SessionFactory sf = null;
    protected Session session = null;
    protected Transaction tx = null;
    
    protected static String sessionFactoryLookupName;
    protected static final String propertiesFileName = "tss.properties";
    protected static final String sessionFactoryLookupNameKey = "sessionFactoryLookupName";
    
    /** Creates a new instance of HSObjectManager */
    protected HSObjectManager() throws Exception {
        init();
    }
    
    protected void init() throws Exception {
        Properties p = new Properties();
        try {
            if (sessionFactoryLookupName == null) {
                p.load(new FileInputStream(propertiesFileName));
                sessionFactoryLookupName = p.getProperty(sessionFactoryLookupNameKey);
            }
        } catch (Exception e) {
            sessionFactoryLookupName = "tss:/SessionFactory";
        }
        
        ctx = new InitialContext();
        sf  = (SessionFactory) ctx.lookup(sessionFactoryLookupName);
        session = sf.openSession();
    }
            
    protected void finalize() throws Exception {
        session.close();
    }
}

so, for example, an action would instatiate a new WhateverHSObjectManager (which extends HSObjectManager) and the try something like:

Code:

    public Study getStudyByNumber(int number) {
        List result;
        try { 
            result = session.find(
                "from Study as study " + 
                "where study.number = ?", 
                new Integer(number),
                Hibernate.INTEGER
                );
        } catch (Exception e) {
            log.debug("Can't retrieve number. Invalid number: " + number, e);            
            return null;
        }
        
        return (Study)result.get(0);        
    }

Which seems to be okay for the first action, but the next action it will return that error.

dtam · **Joined:** Tue Jan 06, 2004 4:51 pm **Posts:** 48

Okay, i did some debugging, and right before the call where I get the

Caused by: org.postgresql.util.PSQLException: Connection is closed. Operation is not permitted.

error, I call

session.isOpen()
session.isConnected()

and they both return true. mmrh..

dtam · **Joined:** Tue Jan 06, 2004 4:51 pm **Posts:** 48

Hi,

I just tried both:

Code:

session.disconnect();
session.reconnect();

and

Code:

session.close();
init();

before the session.find, but no dice.

emmanuel · **Posted:** Thu Jan 15, 2004 3:32 am

The underlying connection is closed, apparently with no relation to Hibernate, do you use a connection pool ? You should, it kind of it's job.