Initializing servlets in webapp

Question

I've read in the Weblogic 5.1 docs that the <load-on-startup> tag is
          unsupported. However, I really
          need to be able to initialize my servlets (read in some properties and set
          some context values) Is there any way to work around this. Using the
          weblogic.properties method of weblogic.system.startupClass etc.. doesn't
          seem to work as it's only affecting the default web application. Has anyone
          worked around this problem?
          

Answer 1

The problem is to know when server startup is complete, because trigger executes right away:
          import javax.naming.*;
          import weblogic.time.common.*;
          import weblogic.common.*;
          public class TestStartup implements Schedulable, Triggerable {
          boolean done = false;
          public void trigger(Schedulable sched) {
          System.out.println("Triggered");
               done = true;
          public long schedule(long time) {
               return done ? 0 : time;
          public static void main(String[] args) {
          try {
          TestStartup test = new TestStartup();
          T3ServicesDef t3 = (T3ServicesDef)(new InitialContext()).lookup("weblogic.common.T3Services");
               ScheduledTriggerDef std = t3.time().getScheduledTrigger(test, test);
               std.schedule();
          System.out.println("Scheduled");
          Thread.sleep(60 * 1000); // simulate some other time-consuming startup tasks
          System.out.println("Startup done");
          } catch(Exception whatever) {
          whatever.printStackTrace();
          works like this:
          Mon Nov 27 22:36:40 PST 2000:<I> <WebLogicServer> Invoking main-style startup teststartup TestStartup
          Triggered
          Scheduled
          Startup done
          Mon Nov 27 22:37:41 PST 2000:<I> <ListenThread> Listening on port: 7001
          Mon Nov 27 22:37:41 PST 2000:<I> <SSLListenThread> Listening on port: 7002
          Cameron Purdy <[email protected]> wrote:
          > Hi Brian,
          > If your startup class schedules itself to be called after the server
          > completes its startup, then you are fine ;-) From a reply I sent:
          >>Have your startup class implement Schedulable and Triggerable and
          > StartupDef
          >>(or whatever the names are) and have it schedule itself when it gets
          > started
          >>up.
          > BTW - I've never done a URLConnection to "localhost" like that but it should
          > work fine since it resolves to 127.0.0.1 on most machines.
          > p.s. Thanks
          > --
          > Cameron Purdy
          > Tangosol, Inc.
          > http://www.tangosol.com
          > +1.617.623.5782
          > WebLogic Consulting Available
          > "Brian Murray" <[email protected]> wrote in message
          > news:[email protected]...
          >> Isn't it funny how the same day you want to do something you see a post on
          >> how to do it? At least that's how I thought it was going to be when I saw
          >> this reply on my way out the door for vacation. Now that I'm back, I
          > can't
          >> seem to make this work.
          >>
          >> We've created a startup class (our first, btw), implementing T3StartupDef.
          >> In the startup method, we try to "poke" the servlet URL:
          >>
          >> URL url = new URL(http://localhost:7001/xxxx/controller);
          >> InputStream is = url.openStream();
          >>
          >> Unfortunately, this results in connection exception "Connection refused:
          > no
          >> further information". It's as if we're trying to access the URL, before
          > the
          >> HTTP listener is ready to respond.
          >>
          >> Could anyone provide a working code sample, or some tips to make this
          >> technique work?
          >>
          >> P.S. Congrats on your mentor recognition Cameron, you earned it.
          >>
          >>
          >> "Cameron Purdy" <[email protected]> wrote in message
          >> news:[email protected]...
          >> > Generally, accomplish this in the init call.
          >> >
          >> > To force on startup, write a WebLogic startup class that pokes
          >> > http://localhost:7001/whateverapp/yourservlet
          >> >
          >> > (java.net.Url open connection)
          >> > --
          >> >
          >> >
          >> > "TK" <[email protected]> wrote in message
          >> > news:[email protected]...
          >> > > I've read in the Weblogic 5.1 docs that the <load-on-startup> tag is
          >> > > unsupported. However, I really
          >> > > need to be able to initialize my servlets (read in some properties and
          >> set
          >> > > some context values) Is there any way to work around this. Using the
          >> > > weblogic.properties method of weblogic.system.startupClass etc..
          > doesn't
          >> > > seem to work as it's only affecting the default web application. Has
          >> > anyone
          >> > > worked around this problem?
          >> > >
          >>
          >>
          >>
          Dimitri