Hi Tim,
I've bought Jason Hunter's book and following is the code from that book
which is also freely available from his website http://www.servlets.com
I think it is better you get that book, it is an excellent book.
import java.sql.*;
import java.util.*;
public class ConnectionPool {
private Hashtable connections;
private int increment;
private String dbURL, user, password;
public ConnectionPool(String dbURL, String user, String password,
String driverClassName, int initialConnections, int increment)
throws SQLException, ClassNotFoundException {
// Load the specified driver class
Class.forName(driverClassName);
this.dbURL = dbURL;
this.user = user;
this.password = password;
this.increment = increment;
connections = new Hashtable();
// Put our pool of Connections in the Hashtable
// The FALSE value indicates they're unused
for(int i = 0; i < initialConnections; i++) {
connections.put(DriverManager.getConnection(dbURL,
user, password), Boolean.FALSE);
}
}
public Connection getConnection() throws SQLException {
Connection con = null;
Enumeration cons = connections.keys();
synchronized (connections) {
while(cons.hasMoreElements()) {
con = (Connection)cons.nextElement();
Boolean b = (Boolean)connections.get(con);
if (b == Boolean.FALSE) {
// So we found an unused connection.
// Test its integrity with a quick
setAutoCommit(true) call.
// For production use, more testing
should be performed,
// such as executing a simple query.
try {
con.setAutoCommit(true);
}
catch(SQLException e) {
// Problem with the
connection, replace it.
con =
DriverManager.getConnection(dbURL, user, password);
}
// Update the Hashtable to show this
one's taken
connections.put(con, Boolean.TRUE);
// Return the connection
return con;
}
}
}
// If we get here, there were no free connections.
// We've got to make more.
for(int i = 0; i < increment; i++) {
connections.put(DriverManager.getConnection(dbURL,
user, password), Boolean.FALSE);
}
// Recurse to get one of the new connections.
return getConnection();
}
public void returnConnection(Connection returned) {
Connection con;
Enumeration cons = connections.keys();
while (cons.hasMoreElements()) {
con = (Connection)cons.nextElement();
if (con == returned) {
connections.put(con, Boolean.FALSE);
break;
}
}
}
}
Thanks & Regards, Goldman
Atchutarao Killamsetty, Sachs
GSAM-IT,Tokyo
Tel:03-5573-7871
-----Original Message-----
From: Tim Stoop [mailto:[EMAIL PROTECTED]]
Sent: Monday, June 26, 2000 7:05 AM
To: [EMAIL PROTECTED]
Subject: Servlets authenticating with MySQL (was: Re: JDBC Connection
Management)
----- Original Message -----
From: William Crawford <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Sunday, June 25, 2000 8:59 PM
Subject: Re: JDBC Connection Management
> None of which is to say that this isn't a useful technique in some
> situations, as Nic described. The two cases where I would suggest this are
> when authentication runs through the database's native authentication
> system, and when transactions might run across multiple servlet
> invocations. However, there are relatively few situations where this will
> come up: authenticating through the database is a pretty resource
intensive
> operation, and you're probably better served storing this information in
an
> LDAP server (via JNDI) or a database table accessed by the server via a
> generic account. I'd also suggest structuring your application to avoid
the
> necessity of stringing a transaction out across multiple invocations: use
> intermediary tables and hold on to an identifier rather than a whole
> connection.
I'm relatively new at Java, servlets and servers, but I'm trying to learn as
fast as I can. I'm not using connection pooling as yet, but I'm studying the
possibility. They way I work is as followed: I have one Connection-object
that connects to MySQL with it's own login/password-combo. Each instance of
a servlet connects anew (sometimes several times during the process of
processing one "string" of data) to the database.
My question isn't as professional as others, but I would like to know the
answer. Reading the post from William, I would like to know if the server is
bogged down due to the authentication-process.
Another question is, where can I find documentation about connection-pooling
and how to implement this? (I'm using mm.mysql for JDBC.)
Kind regards,
Met vriendelijke groet,
Tim Stoop
___________________________________________________________________________
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff SERVLET-INTEREST".
Archives: http://archives.java.sun.com/archives/servlet-interest.html
Resources: http://java.sun.com/products/servlet/external-resources.html
LISTSERV Help: http://www.lsoft.com/manuals/user/user.html
___________________________________________________________________________
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff SERVLET-INTEREST".
Archives: http://archives.java.sun.com/archives/servlet-interest.html
Resources: http://java.sun.com/products/servlet/external-resources.html
LISTSERV Help: http://www.lsoft.com/manuals/user/user.html
