Applet interaction questions

Howdy.
I'm generating a map in an applet using a library based on swing classes.
I need to be able to:
-- query the db on the host server from within the applet to alter the map;
-- save a snapshot of the map to the server (I've got code that saves a snapshot, but I need to be able to save that on the host server);
-- if possible, receive messages from javascript controls on the browser page where the applet resides, and respond to them.
It seems like I may need to sign the applet, but I'm not trying to do anything on the client machine; just to interact with the host server.
Can someone point me in the right direction? I've been out of the java world for a bit, so all the details are slow coming back...
Thanks much.

Hi,
I have some questions regarding to the
HttpURLConnection implementation used in Applet.
1. Is the connection made when I do
URL.openConnection or when I flush/close the
OutputStream?The local resources are taken when the openCOnnection is called. The request is made to the server when the getInputStream getContent getResponseCode or the one of the other input methods is called.
2. Will the binaray data in content be chunked if I
set the Content-Type to application/octet-stream
along with Content-Length?Don't know.
>
3. After the OutputStream been closed can I still use
the Connection for read?Yup (note you will have to do this to actually send the request to the server...)
>
4. Is it possible for me to lose any data in the Http
request I send through the HttpURLConnection?Not sure, but my thought has always been any data sent across HTTP can be lost en route. There will be some effort from the server to recover lost packets, but I do not know the details...
>
Thanks,
Michael

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I am interested in how users can post questions using IP/TV while the presentation is ongoing. What is the process behind this as I don't really see how it works, any kind of insight would be useful.
Many thanks Alex

When you set up the program, you can (or not) enable interactive "from the field" questions.
The client provide a button that can be pressed to flag the presenter that a field question is pending.
The presenter can then address the questions as possible.
Depending on the scope and location of the audience, you may also consider bringing up a conference bridge for voice-based questions.
Good Luck
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I'm sure this is an easy question, but how do you access subdirectories in your applet's jar file?
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* META-INF
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Actually now I am using:
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JSF Backing bean / JSP interaction questions

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Could you pl tell me how to pass parameter thru CommandButton
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Id Text
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<managed-bean-name>greetingForm</managed-bean-name>
<managed-bean-class>com.mycompany.GreetingForm</managed-bean-class>
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<managed-property>
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Interactive question DVD creation?

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Applet security question

Hi,
I was given the following instructions by a company when I contacted their tech support to ask why their applet was giving me warning dialog boxes saying that their certification had expired:
+++ BEGIN QUOTE +++
Go to c:\program files\javasoft\jre\1.3\lib\security\java.policy and open with Notepad.
Insert the following at the top of this file:
grant {permission java.security.AllPermission;};
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This comment line above should already be in the file and should be used as a reference point. Save the file and try the web client again.
+++ END QUOTE +++
Can anyone tell me what this actually does?
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Wow that's scary and BAD BAD advice. If you do that, then ANY and ALL applets can get access to your local system (including ones with nefarious plans to delete operating system files, etc.)
The correct way is this:
grant codeBase "file:c:/somepath/dir/-" {
permission java.security.AllPermission;
(assuming it's a file path)
If its an applet from a specific domain:
grant codeBase "http://www.somedomain.com/-" {
permission java.security.AllPermission;
NEVER ever do what they said.

Applet installation question

I am trying to install an applet using a non default
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}else {
register(buffer, (short)(offset+1) ,
(byte)(buffer [offset]));
} // end of the constructor

In order to answer the original question:
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Applet POSTing Question

Is there anyway to make an Applet do a POST command to my Servlet on the server?
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Regards,
Richard
[email protected]

I recommend using netscape.javascript.JSObject.
You can obtain this by downloading Netscape.
In your applet do something like this:
m_window JSObject;
m_window = (JSObject) JSObject.getWindow(this);
m_window.eval("parent.frameName.someJSVar=1");
m_window.eval("parent.frameName.someJSFunction();");
This is a good method for submitting forms in some
seperate frame without reloading your applet.
Good luck,
Gil

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Well here is my first question of what promises to be many. Nice to meet you all. Here goes:
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I wouldn't worry about it, I get the same errors using the computers at Uni. It's never stopped me anyway. I'm not sure what causes it, something to do with WinNT/2000 and profiles/users.
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Radish21

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First the main idea of the project. I have a system where I need to use an applet to process an image and display it on a web page.
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Thanks! Any suggestions out there will help me.

First the main idea of the project. I have a system where I need to use an applet to process an image and display it on a web page.
I have written the applet that does the image processing and it saves the finished image on the users disc. It then uses the showDocument(url) method to pass the URL of the local file to a java script function on the html page.
This is where the problem occurs. Firefox won't display that image and complains about a security error because the remote page is linking to a local file. Interestingly enough IE6 on windows has no issue displaying the generated image.
I really have two questions.
1)Is there a quick/dirty fix that just simply gets around the security barrier Firefox has?
2)Is there some other, more elegant, way of getting an image from an applet to the webpage. It doesn't matter if it requires writing to disc or not.
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Thank you, Lilybiri! Regarding #1, the actions should execute at the same time, rather than in a timed sequence.
Regarding my question 3, I figured it out. I just have to click into the text field and then hit the key I want on my keyboard (the "Allow Mouse Click" option is no longer greyed out following that).
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Am I missing something?

Four Java Applet signing questions

hi all;
I'd like to ask a few quick questions about applet signing. As you know there is a "Security Warning" Gray Alert box that appears when the user tries to load your signed applet.
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3. Is there some way to inspect the PC to determine weather your applet loaded properly - apart from seeing a properly working applet ? For example , If I want to make sure it is being cached properly.
4. When a new version of the applet is available on the server ? how does the browser know to download something ? is that something I would code for manually or would is this automatically handled behind the scenes.
Thanks in advance
Stephen

I can only reply to nr 1 but looking at java.security.AccessControl there is a method called checkPermission() you can use.

Applet persistance question (basic?)

All:
Forgive the ignorance, but I am not a Java programmer at all... but am looking for some info.
What is the scope of a (untrusted) java applet in regards to IE browser sessions? For instance, if a web page initiates an applet load, does the applet stay in memory and continue to run after the user navigates away from the original page?
We are trying to find out if it is possible for a page to load a particular applet that records the URL string of IE browser windows, and have this applet persist throughout the user's browser session, even if they leave the original page, and if they open new browser windows. Is this possible, or is it just crazy?
Thanks for any help!
phong

We are trying to find out if it is possible for a page
to load a particular applet that records the URL
string of IE browser windows, and have this applet
persist throughout the user's browser session, even if
they leave the original page, and if they open new
browser windows. Is this possible, or is it just
crazy?And then make the user crazy trying to download anti spyware and adware and stuff. The question is why do you want the applet to be running once the user has left the page and would you ask for his permission to do so. Just as there is a law for the telemarketing guys there should be another one for these spyware guys who want to run there own agenda on the clients machine without his concent.

Applet tag question

I am working with applets and have been getting the classdefnotfounderror exception and a wrong name error.
After pouring over the archives and messing around, I have found a
solution to my problem, but I don't know why it works. I think it has to do with packages, but I'm not sure.
I have two versions of Asteroids, one which has "package Asteroids" at the top
of each file, and one that has no package.
First with the version that is in a package: If I have the html file in the
same directory as the class files, I cannot get the applet tag to work
properly. If I back it up a directory (just outside the Asteroids directory), this works:
<applet
codebase = "."
code     = "Asteroids/Asteroids.class"
width    = "640"
height   = "480"
</applet>
{code}
One old post I found said that the wrong name error indicates that the qualified name is incorrect ( so my incorrect name would be Asteroids.class) and that the full name should include the package, so mine would be Asteroids/Asteroids.class, I think. Is that correct? If so, why wouldn't this code work inside the same directory as the class files?
For the version that is not in a package, the opposite seems to work.
{code:java}
<applet
codebase = "Asteroids/"
code     = "Asteroids.class"
width    = "640"
height   = "480"
</applet>
{code}
This code works for the version which is not in a package, but does not work for the version in a package, ( and vice versa for the code above). It seems like either code should work in either case. What am I missing?
Thanks,
Matt

I don't know what your understanding of packages and applet codebase is. These 2 tutorial sections should clarify your understanding, though.
http://java.sun.com/docs/books/tutorial/java/package/index.html
http://java.sun.com/docs/books/tutorial/deployment/applet/html.html

InDesign interactive question...

I have encountered a problem recently with InDesign interactive that I wasn't aware of up till now. When I position objects on the screen, that have motion applied, if they are placed in the same position on another page with no motion applied, they preview out of position... i.e they look visually different. Up or down a few pixels. I've even noticed that images and items are positioned where I want them in the X and Y coordinates – then when exporting they look out of position??? This is really causing me a lot of vexation at this point as I was working on a project for months when I just noticed some of this. Why does an item that is placed exactly where I want it, appear different when exported out as a swf and previewed. Is this something I wasn't aware of with pixel preview or something??? Anyone encountered this, and is there a way around it.
Thanks!

CreateSmart wrote:
Basically if you create 4 objects, say squares... and turn them into buttons and position them on a page. Then apply motion to them, say fly in from right. If you take those same 4 buttons and position them on another page in the exact same position with no motion applied... when you export the 2 pages out, the page with the buttons that have motion applied is shifted 2-3 pixels up! So say you want the buttons to fly in from the right initially but on subsequent pages you want them to be fixed in their position. The buttons with motion applied after exporting are shifting or not exactly in the same position as the non - moving buttons. Needless to say that's not acceptable for presentation purposes. It's visible! Apparently I never noticed it because I was applying motion to all pages... Very disturbing as I use InDesign a lot for interactive stuff. Maybe a bug... not sure but I'd love to figure out what the problem is and or ask Adobe about it. Too bad you can't just call em' up on the phone anymore...
As Peter S said, it's also completely outside my workflow. However, a thought popped up: have you tried creating the objects on a master page that's applied to the particular document pages involved, then releasing (aka "override them locally") them on the page where you'll apply animation? If not, give it a try and let the forum know the results.
HTH
Regards,
Peter Gold
KnowHow ProServices

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