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WHEN YOU POST, include all relevant version numbers, log files,
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Gustavo,
I was on JDK 1.2.2. I installed JDK 1.3 and the problems had gone.
There seems to be a problem with Sun's JDBCODBC. If 1.3 is no
option you could try a different driver
check out http://www.inetsoftware.de (this is from Brett Knights)
He says: I've been using their drivers for over a year with great results.
> -----Ursprüngliche Nachricht-----
> Von: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]Im Auftrag von Gustavo
> Arruda
> Gesendet: Dienstag, 17. Oktober 2000 00:27
> An: Java Apache Users
> Betreff: Memory consumption due to erroneous access to database
>
>
> ----------------------------------------------------------------
> BEFORE YOU POST, search the faq at <http://java.apache.org/faq/>
> WHEN YOU POST, include all relevant version numbers, log files,
> and configuration files. Don't make us guess your problem!!!
> ----------------------------------------------------------------
>
> Hi folks,
>
> I am using Windows NT 4.0 plus JDK1.2.1 plus Apache 1.3.12 plus JSERV1.0.
>
> I have written a class to read the DataBase through a JDBC/ODBC
> bridge, but
> I am afraid it is not throwing objects to garbage or closing connections.
> Everytime I call any Servlet that uses this class, it works fine but the
> amount of memory used by "java.exe" process increases by 200k or more. So,
> after some repeated calls to any Servlet, java.exe is so big that it stops
> working and I cant run Servlets anymore. The error in the log file says
> "Jdbc:Odbc : can´t read anymore tables".
>
> I am sending you the code of the class 1 that access the DB , the code of
> class 2 that extends the HttpServlet class, and the code of class 3 that
> extends class2. The problem is I dont know how to close the connection to
> the database after the ResultSet is passed to the CLASS3 (see
> codes, I hope
> you do!)
>
> Thanks in advance,
>
> Gustavo Arruda
>
> //CLASS 1 - DBSynchronizer - Access the DB through methods select
> and update
> import java.io.*;
> import java.sql.*;
> public class DBSynchronizer {
>
> private static final String url="jdbc:odbc:carona";
> private static boolean isReading = false;
> private static boolean isWriting = false;
> private static Connection readCon;
> private static Connection writeCon;
> private static Statement select = null;
> private static Statement update = null;
> private static ResultSet result = null;
> public DBSynchronizer() {
> try {
> Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
> readCon = DriverManager.getConnection(url,"","");
> writeCon = DriverManager.getConnection(url,"","");
> } catch (Exception e) {}
> }
>
> public synchronized ResultSet select(String query) {
> while (isWriting) try {
> wait();
> } catch (InterruptedException e) { }
> isReading = true;
> try {
> select = readCon.createStatement();
> result = select.executeQuery(query}
> catch(Exception e) {
> e.printStackTrace();
> }
> isReading = false;
> notifyAll();
> return result;
> }
>
> public synchronized int update(String updt) {
> int inserted=0;
> while (isReading) try {
> wait();
> } catch (InterruptedException e) { }
> isWriting = true;
> try {
> update = writeCon.createStatement();
> inserted=update.executeUpdate(updt);
> } catch(Exception e) {
> inserted=-1;
> }
> isWriting = false;
> notifyAll();
> return inserted;
> }
> }
>
> //CLASS2 - HttpServletSQL makes the CLASS1 methods available through an
> object called sql
> import java.io.*;
> import java.sql.*;
> import java.util.*;
> import javax.servlet.*;
> import javax.servlet.http.*;
>
> public class HttpServletSQL extends HttpServlet {
>
> protected static DBSynchronizer sql;
>
> public void init (ServletConfig config) throws ServletException {
> super.init(config);
> // Created only by the first Servlet
> if(sql == null)
>
> sql = new DBSynchronizer();
> }
> }
> }
> //CLASS3 - A normal servlet that extends class2
> import java.io.*;
> import javax.servlet.*;
> import javax.servlet.http.*;
> import java.sql.*;
> import java.util.*;
>
> public class Servlet_counter extends HttpServletSQL {
> public void doGet (HttpServletRequest req, HttpServletResponse res)
> throws ServletException, IOException
> {
> res.setContentType("text/html");
> ServletOutputStream out = res.getOutputStream();
>
> String fontSize = req.getParameter("fontSize");
> String fontColor = req.getParameter("fontColor");
> if (fontSize == null) fontSize = "2" ;
> if (fontColor == null) fontColor = "white" ;
> String getCod = "Select Max(Cod) AS MCOD FROM ACCESS" ;
>
> ResultSet rs= sql.select(getCod);
> int cod = 0;
> try {
> if (rs.next()) {
> cod = rs.getInt(1);
> out.print("<font size=+"+fontSize+" color="+fontColor+"> "+
> (cod+1)+"</font>");
> }
> rs.close();
> }
> catch(Exception e) { }
> }
> }
>
>
>
> --
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