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Why does an applet not initialize sometimes?

P: n/a
I've got a web page that uses frames. One of the frames loads an HTML page
that redirects to a 3rd HTML page. This third page loads a Java applet -
ProScroll.class - that runs a "news ticker" across part of my screen. The
page is set up to refresh itself every 15 minutes using a <meta> tag. The
idea is that the news ticker can pick up new information every 15 minutes.

The machines we're running on have Sun's JRE 1.4.2_0x.

What we're noticing is that the applet (which we found via web searches)
does not reload properly on many of the refresh attempts. It's not
consistent, but we end up with a large gray spot on the screen where there
should be a news ticker. The page itself is reloading, since the page will
attempt a reload in another 15 minutes, and this sometimes works and the
news ticker reappears.

We are using an applet tag, rather than the <object> tag. Is that a problem
(rather than just being old school)?

I'm trying to understand what's happening. We're running inside an
application we wrote using Delphi 7 and the TWebBrowser component, but we've
had the same problem running the pages inside Internet Explorer 6.0
(although less often). I've not seen anything in the Java console to
indicate what the problem is (the Java console doesn't get updated
information when we're running our own application).

Anyone have any ideas on what might be happening, or how I might go about
tracing the problem down?

Conversely, is there any way that I can rework the page to recognize that
the applet didn't start, and thus force a reload to try and force the applet
to initialize?

Thanks....
Jul 17 '05 #1
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4 Replies


P: n/a
Warrick Wilson wrote:
I've got a web page that uses frames. One of the frames loads an HTML page
that redirects to a 3rd HTML page. This third page loads a Java applet -
ProScroll.class - that runs a "news ticker" across part of my screen. The
page is set up to refresh itself every 15 minutes using a <meta> tag. The
idea is that the news ticker can pick up new information every 15 minutes.

The machines we're running on have Sun's JRE 1.4.2_0x.

What we're noticing is that the applet (which we found via web searches)
does not reload properly on many of the refresh attempts. It's not
consistent, but we end up with a large gray spot on the screen where there
should be a news ticker. The page itself is reloading, since the page will
attempt a reload in another 15 minutes, and this sometimes works and the
news ticker reappears.

We are using an applet tag, rather than the <object> tag. Is that a problem
(rather than just being old school)?

I'm trying to understand what's happening. We're running inside an
application we wrote using Delphi 7 and the TWebBrowser component, but we've
had the same problem running the pages inside Internet Explorer 6.0
(although less often). I've not seen anything in the Java console to
indicate what the problem is (the Java console doesn't get updated
information when we're running our own application).

Anyone have any ideas on what might be happening, or how I might go about
tracing the problem down?

Conversely, is there any way that I can rework the page to recognize that
the applet didn't start, and thus force a reload to try and force the applet
to initialize?


Warrick,

What is the output of the Java Console? I have noticed on some
commercial sites that an applet sometimes will not reload properly.
When I examined the output of the Java Console, I found that the issue
was inside the JFC regular expression packages. (In particular, there
is a threading issue in the initialization of the
java.util.regex.Pattern class. I tried to file a bug report on this,
but Sun did not accept the bug.)

Ray

--
XML is the programmer's duct tape.
Jul 17 '05 #2

P: n/a

"Raymond DeCampo" <rd******@spam.twcny.spam.rr.spam.com.spam> wrote in
message news:N_*******************@twister.nyroc.rr.com...

Warrick,

What is the output of the Java Console? I have noticed on some
commercial sites that an applet sometimes will not reload properly.
When I examined the output of the Java Console, I found that the issue
was inside the JFC regular expression packages. (In particular, there
is a threading issue in the initialization of the
java.util.regex.Pattern class. I tried to file a bug report on this,
but Sun did not accept the bug.)

Ray


Interestingly, the Java console does not get any information when my program
is running. That is a Delphi 7 program with a TWebBrowser control that loads
the page that loads the Java applet. So I can't provide any further details
on why things are not working properly. I tried running within IE, but it
didn't stop working during my test run. It's not something that's
predictable, but it happens often enough to be annoying.
Jul 17 '05 #3

P: n/a
"Warrick Wilson" <wa******@mercuryonline.com> wrote in message news:<7d*****************@newsread1.news.pas.earth link.net>...
"Raymond DeCampo" <rd******@spam.twcny.spam.rr.spam.com.spam> wrote in
message news:N_*******************@twister.nyroc.rr.com...

Warrick,

What is the output of the Java Console? I have noticed on some
commercial sites that an applet sometimes will not reload properly.
When I examined the output of the Java Console, I found that the issue
was inside the JFC regular expression packages. (In particular, there
is a threading issue in the initialization of the
java.util.regex.Pattern class. I tried to file a bug report on this,
but Sun did not accept the bug.)

Ray


Interestingly, the Java console does not get any information when my program
is running. That is a Delphi 7 program with a TWebBrowser control that loads
the page that loads the Java applet. So I can't provide any further details
on why things are not working properly. I tried running within IE, but it
didn't stop working during my test run. It's not something that's
predictable, but it happens often enough to be annoying.

I don't know enough about TWebBrowser to be 100% sure but if you
aren't seeing the erratic behavior in IE but you are seeing it in the
TWebBrowser control, signs could be pointing to that being the problem
and not the applet itself.
Jul 17 '05 #4

P: n/a
Keith R. Hudson" <kh*****@vintek.com> wrote in message >
I don't know enough about TWebBrowser to be 100% sure but if you
aren't seeing the erratic behavior in IE but you are seeing it in the
TWebBrowser control, signs could be pointing to that being the problem
and not the applet itself.

Keith et al,

You're right. There's not so much a problem with the applet as with the
reload of the page it is in. I found out that the applet IS loading, but it
is getting a 0x0 place on the page rather than 1024x77. The layout is done
in percentages.

I found that I can use Javascript to query the size of the allocated panel
for the applet, and if it is 0x0, I force a reload. That test has been
running for a couple of days, and it seems to be working quite well.

Thanks to all for your suggestions.

Warrick
Jul 17 '05 #5

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