Question about closing a glassfish jdbc connection pool connection

Hello,
I have a database handler called glassfishDB, it handles database queries for a servlet I wrote. Anyways, Ive been noticing that after awhile the servlet stops responding, so started to debug and came up with this:

----Log File Rotated---
RAR5117 : Failed to obtain/create connection from connection pool [ tracking ]. Reason : In-use connections equal max-pool-size and expired max-wait-time. Cannot allocate more connections.
RAR5114 : Error allocating connection : [Error in allocating a connection. Cause: In-use connections equal max-pool-size and expired max-wait-time. Cannot allocate more connections.]
Database Close Error: java.lang.NullPointerException
StandardWrapperValve[xmlDataServices]: PWC1406: Servlet.service() for servlet xmlDataServices threw exception
java.lang.NullPointerException
        at xmlDataServices.getServerID(xmlDataServices.java:170)
        at xmlDataServices.processRequest(xmlDataServices.java:46)
        at xmlDataServices.doPost(xmlDataServices.java:331)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:738)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:831)
        at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:411)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:317)

which obviously indicates that the servlet cant run because it cant get a database connection. So I went back to my servlet and glassfishDB class, and started poking around. In the servlet, all the db calls are closed when they are done being used - so that was one issue out of the way, the only other thing I can come up with is that I am not closing the connections down properly. Can someone please tell me how to fix this error? The code for my glassfishDB is below and here is an example of its usage:

glassfishDB db = new glassfishDB("jdbc/tracking_pool");
db.executeQuery("select * from sometable");
db.close();

or the same thing but with an update you dont need to close, as it closes automatically:

db.executeUpdate("update sometable set somecolumn = 'somevalue'");


Worth 500 points.

Thanks,
Rick

/*
 * Database.java
 *
 * Created on November 1, 2006, 1:28 AM
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */
 
 
 
//Database Connectivity - Requires ODBC
import java.util.Hashtable;
import javax.sql.*;
import java.sql.*;
import javax.naming.*;
 
public class glassfishDB {
	Statement stmt;
	ResultSet rs;
	ResultSetMetaData meta;
	Connection con;
	long numberofrows = -1;
        int errorState = 0;
        String errorMessage = "";
        String poolname = "";
        
	glassfishDB(String poolName)
	{
            this.poolname = poolName;
	}
 
        public static DataSource getDataSource(String dsName) throws NamingException 
        {
            InitialContext context = null;
            context = new InitialContext();
            DataSource dataSource = (DataSource) context.lookup("jdbc/" + dsName);
            return dataSource;
        }
        
	void executeQuery(String query)
	{
            try 
            {
                DataSource ds = getDataSource(poolname);
		con = ds.getConnection(); 
                stmt = con.createStatement();
                // Do db operations.
                // Do not close driver connection
		rs = stmt.executeQuery(query);
		rs.setFetchSize(1); 
		meta = rs.getMetaData();
	    }
	    catch (Exception e)
	    {
                //System.out.println("Database Connection Error:" + e.toString());
                errorMessage = e.toString();
                errorState = 1;
	    }
	}
 
	void executeUpdate(String query)
	{
            try 
            {
                DataSource ds = getDataSource(poolname);
                con = ds.getConnection();
                stmt = con.createStatement();
		stmt.executeUpdate(query);
                con.close();
            }
	    catch (Exception e)
	    {
		//System.out.println("Database Connection Error:" + e.toString());
                errorMessage = e.toString();
                errorState = 2;
            }
	}
 
	long getRowCount()
	{
		try
		{
			int start = rs.getRow();
			rs.last();
			int last = rs.getRow();
 
			rs.first();
 
			numberofrows = last - start;
		}
		catch(Exception e)
		{
			//System.out.println("Database getRowCount() Error: " + e.toString());
                        errorMessage = e.toString();
                        errorState = 3;
		}
          return numberofrows;
	}
 
        synchronized Hashtable getNextRecord()
	{
		Hashtable ht = new Hashtable();
 
		//Assign the next record to the hashtable
		try
		{
 
			if (rs.next())
			{
				////System.out.println("Data Present");
				//loop over the variable names and assign them and their values to the hashtable
				for (int col = 1; col <= meta.getColumnCount(); col++) {
				   String varName = meta.getColumnName(col).trim();
				   ////System.out.println("ColNAME " +varName);
				   String tdata = rs.getString(col);
 
				   if (tdata == null)
				   	  tdata = "";
 
				   ht.put(varName, tdata);
				}
			}
			else
			{
				ht = null;
			}
		}
		catch (Exception e)
		{
			//System.out.println("Database Read Error: " + e.toString());
                        errorMessage = e.toString();
                        errorState = 4;
		}
 
		return ht;
	}
 
	void close()
	{
		try
                {
                    con.close();
                }
                catch (Exception e)
                {
                    System.out.print("Database Close Error: " + e.toString() + "\n\n");
                }
        }
 
}

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