Hello developers,
hmm, I hope this is not a "long time discussed" problem!
If so, please forgive me - I'm new to this mailinglist ;-)
Ok, here is my problem:
I have a class for accessing my database-routines with an
instance like this:
-------------------------
public class Database
{
private static Database onlyInstance = null;
/* Private no-args constructor */
private Database() {
init();
}
/** Private factory method (make a single instance of this
class) */
private static Database instance() {
if (onlyInstance == null)
onlyInstance = new Database();
return onlyInstance;
}
/** Init (Connect to DB) */
public void init()
{
try {....
--------------------------
...and I have a servlet which tries to get an instance of this class:
--------------------------
public class testdb extends HttpServlet
{
/** Init the Servlet (get instance of db) */
public void init() throws ServletException
{
Database database =
(database)getServletContext().getAttribute("database");
if (database == null) {
getServletContext().setAttribute("database",
database.instance() );
}
}
public void doGet() {...
--------------------------
If I try to get the instance back in one of the doGet/Post-methods, I
get a "ClassCastException" for Database. This is how I try to get the
instance:
--------------------------
....
Database database =
(Database)getServletContext().getAttribute("Database");
ResultSet rs = database.getSomething(id);
....
--------------------------
It looks like that the getAttribute-methode doesn't give back a object
of type Database. Or is there something complete wrong with that code ??
(..or likely with my concept of interservlet-communication ??)
I use a Linux box with the Blackdown-JDK 1.1.7v3 with a Jetty-Webserver.
Thanks for all contributions to this question.
bye
MaZe
-------------------------------------------------------------
BSB Software GmbH mailto:[EMAIL PROTECTED]
Mayfarthstra�e 25-27 Internet: http://www.bsb-software.com
60385 Frankfurt
Tel: +49 69 94 414 718 - Fax: +49 69 94 414 719
Internet * Netzwerke * Consulting * Schulungen
-------------------------------------------------------------
___________________________________________________________________________
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
