App Advice?

[Patrick T]

Hi - I need to create an web-based application that will allow users to
'upload' images and be able to zoom/pan the images. Originally, i was
thinking of doing this via dhtml, but after looking at some of the
images they would be using, i relized it would be impractical due to
the file size (b/w 2-6 MB each - planning on using approx 20 each time
they use the app). Obviously, it would be very time consuming to
upload each image every time to the server and then be able to
minipulate it.

Question: Is there anyway I can create a java applet that would allow
users to USE an image from their desktop, without actually uploading it
to the webserver - similar to a client-based application. Basicly i
want to have the ability to LOAD an image in the applet but without
having to actually upload it. Is that possible using java applets????
Please let me know or if you have any suggestions on other possible
solutions. Thanks,

-Pat-

 

[Andrew Thompson]

Question: Is there anyway I can create a java applet that would allow
users to USE an image from their desktop, without actually uploading it
to the webserver - similar to a client-based application. Basicly i
want to have the ability to LOAD an image in the applet but without
having to actually upload it. Is that possible using java applets????

Yes. (Yes. Yes! Yes!!!!).
The applet needs to be jar'd and signed.

HTH

 

[jan V]

Why cripple your options with an applet in a web page? Create a full-blown
application and let them install it on their machine. Using java.net's
classes it becomes trivial to talk to any server.

Or even use JavaWebStart? Don't use applets for heavy tasks like those you
describe...

 

[Andrew Thompson]

Why cripple your options with an applet in a web page? Create a full-blown
application and let them install it on their machine. Using java.net's
classes it becomes trivial to talk to any server.

Or even use JavaWebStart?

(Which would require the application to be signed, or
else it gets a security sandbox similar to sandbox normally
applied to applets.)

..Don't use applets for heavy ...
heavy?

..tasks like those you describe...

What way do you mean 'heavy'? And more particularly, what
is it you think a JWS'd application could do that a JWS'd
applet would have trouble with?

 

[Roedy Green]

Question: Is there anyway I can create a java applet that would allow
users to USE an image from their desktop, without actually uploading it
to the webserver - similar to a client-based application

There are at least four places the image could come from:

1. the server

2. the jar

3. the local file system. You give the guy a JFileChooser to selecct
it. However, for this sort access, you need a signed Applet.

4. anywhere on the web, given its url. For this too you need a signed
Applet.


See http://mindprod.com/jgloss/signedapplets.html

This sort of app is often done with JAWS.


see http://mindprod.com/jgloss/javawebstart.html

see http://mindprod.com/jgloss/image.html
for the sort of code you need to access the various sources.


--
Bush crime family lost/embezzled $3 trillion from Pentagon.
Complicit Bush-friendly media keeps mum. Rumsfeld confesses on video.
http://www.infowars.com/articles/us/mckinney_grills_rumsfeld.htm

Canadian Mind Products, Roedy Green.
See http://mindprod.com/iraq.html photos of Bush's war crimes

 

[Roedy Green]

What way do you mean 'heavy'? And more particularly, what
is it you think a JWS'd application could do that a JWS'd
applet would have trouble with?

The big thing is JAWS it would not have to be downloaded on each use.

Another, is you could run it without a browser, giving you all the
RAM.

Another is it is easier to debug an application than an Applet. you
can turn an application into JAWS without changing a line of code,
just adding a JNLP file and perhaps and installer class.

The downside is for JAWS to work, you need JNLP mimes set up in the
browser and server, and a JNLP association to Javaws.exe.


The Opera people have obstinately refused to that automatically in
their browser, though they otherwise support Java.



--
Bush crime family lost/embezzled $3 trillion from Pentagon.
Complicit Bush-friendly media keeps mum. Rumsfeld confesses on video.
http://www.infowars.com/articles/us/mckinney_grills_rumsfeld.htm

Canadian Mind Products, Roedy Green.
See http://mindprod.com/iraq.html photos of Bush's war crimes

 

[Roedy Green]

What way do you mean 'heavy'? And more particularly, what
is it you think a JWS'd application could do that a JWS'd
applet would have trouble with?

too bad newsgroups don't let you post a formatted HTML table. This
would be a lot easier to fathom.


How do you decide whether to use an Applet or a Java Web Start
Application?


Applets vs JAWS
Feature Applets JAWS


Requires browser to run? Yes No


Must wait for download every time?
Yes No

How To Install Just view a page containing the
Applet.


Just click a
button on a page to install the JAWS application.


Auto-updating Yes Yes


Digitally Signed Yes, to doing do anything interesting, though
simple Applets can be unsigned.

usually

Client Prerequisites Requires Java JRE installed on machine and in
browser.

Requires Java
JRE installed on machine. Requres application/x-java-jnlp-file MIME
type association to javaws.exe set up in browser. Requires *.jnlp
association to javaws.exe


Server Prerequisites just a vanilla HTTP server to server web pages
and jar files. So special server side code is needed.

requires *.jnlp files
be served with application/x-java-jnlp-file MIME type. Ideally you
also install the JNLP protocol to serve jar changes more efficiently,
though it is not necessary.


Ease of Writing Must be designed as an Applet from the start.


You can turn any ordinary
application into a JAWS one by adding *.jnlp file and perhaps an
installer class.


User Comfort
Fear Factor below average. Ironically, MS propaganda has users
fearing Applets far more than JavaScript when, in actuality, Java is
hundreds of times safer.
poor
--
Bush crime family lost/embezzled $3 trillion from Pentagon.
Complicit Bush-friendly media keeps mum. Rumsfeld confesses on video.
http://www.infowars.com/articles/us/mckinney_grills_rumsfeld.htm

Canadian Mind Products, Roedy Green.
See http://mindprod.com/iraq.html photos of Bush's war crimes

 

[Andrew Thompson]

How do you decide whether to use an Applet or a Java Web Start
Application?

[snip]

You do not seem to realise that applets can be JWS, which
makes the rest of the comments irrelevant.

JWS applets can have all the advantages of JWS application,
and note that an *unsigned* JWS *application* is deployed in
a strict security sandbox - similar to that used for an unsigned
applets.

There is little difference between JWS applications and JWS applets.