On a related note, I'm pretty sure you could condense all the code you have to just one line, something like:
DataSource ds = (DateSource)new InitialContext().lookup("java:comp/env/jdbc/wms")
I'm fairly certain that works. That might be clearer to you.
-- Frank W. Zammetti Founder and Chief Software Architect Omnytex Technologies http://www.omnytex.com
Eric Wulff wrote:
helpful somewhat... at least in helping me narrow my question. So what is this "java:comp/env"? What exactly is being returned based on this string passed to lookup()?
Eric
On Sat, 06 Nov 2004 23:35:34 -0500, Frank W. Zammetti <[EMAIL PROTECTED]> wrote:
I'll give it a shot...
All JNDI resource lookups occur relative to some context. The code you posted first gets the default initial context, then looks for a resource named "java:comp/env" relative to that default context. It then gets a reference to a DataSource that exists within the context "jdbc/wms" relative to "java:comp/env"
You can ROUGHLY think of this the same way you do URLs... in a sense, the "java:comp/env" might be something like www.apache.org. That gives you a starting context. Then if you want to retrieve a particular file in that domain, you look it up relative to the domain (i.e., www.apache.org/tomcat.htm).
Same thing here... There is a hierarchy of JNDI resources, a tree structure, that has an initial context as the root. You then are in a sense constructing a path to your DataSource, and it might look something like /initial_context/java:comp/env/jdbc/wms (not exactly, but you get the idea).
Does that help any?
-- Frank W. Zammetti Founder and Chief Software Architect Omnytex Technologies http://www.omnytex.com
Eric Wulff wrote:
I just returned from working on a tutorial at sun which I was inspired to go over based on my lack of understanding of the code snippet below. I'm trying to fully understand what's going on. Docs state that the code...
initialContext.lookup("java:comp/env")
returns a named object. Best I can tell is that this is a reference to a starting point in my directory... or something like that. Is anyone willing to explain what initialContext.lookup() fundamentally takes care of when called?
Context initialContext = new InitialContext(); Context context = (Context) initialContext.lookup("java:comp/env"); DataSource dataSource = (DataSource) context.lookup("jdbc/wms");
thx Eric
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