Using of InitialContext & datasource

Question

In my web-base application, I use the following commands to access db in a "command object"
InitialContext ic = new InitialContext();
datasource = (DataSource) ic.lookup("java:comp/env/jdbc/Mydb");
The application work fine up to now. However, my application will contain several thousands of this kind of "command object" and will allow about 50 concurrent users.
I want to know whether this commands work fine when our system and number of user growth larger and larger. Is there any other better db accessing method?
Please advise and provide examples. Many thanks.

Answer 1

I meant something different.
You got a CommandObject:
public class SomeCommandObject {
  private DataSource ds;
  public SomeCommandObject(DataSource ds) {
    this.ds = ds;
  public void doSomething() {
    Connection con = ds.getConnection();
    Statement stmt = con.createStatement();
}Note you could also use a setter here instead of passing the DataSource to the constructor.
The DataSource itself is created here:
public class CommandObjectFactory() {
  private DataSource ds;
  public CommandObjectFactory() {
    InitialContext ic = new InitialContext();
    ds = (DataSource) ic.lookup("java:comp/env/jdbc/Mydb");
  public CommandObject createObject() {
    return new SomeCommandObject(ds);
}Whenever you need a CommandObject, you should use the factory to create one. You should use the Factory Method pattern here. See Gamma et al for example (http://patterndigest.com/patterns/FactoryMethod.html). Note that the code above is just an example. You need to use some inheritance here to make it better (the ds attribute and constructor should be in a super class).
This way you decoupled your command objects from the creation of the datasource. If you need to change the datasource, you can do it in one place.
There are some other ways to construct a CommandObject. Instead of having a separate method/class to create your objects You could pass some information to the createObject method, which decides which object will be created (for instance the classname). In that case you'll need reflection.
Cheers,
--Arnout