ImageIO usage in applets.. Please help...

[Kimberly Hendershot]

Hi.

I have an applet/servlet pair that communicate some images. The applet is
a paint-like program that allows the user to draw a picture. It then takes
this picture and sends it via ImageIO to a servlet which can create a file
on the server to save the image in .png format also using ImageIO.

I developed and tested my applet/servlet pair using Tomcat 4.0.3 using my
local machine as a host. Everything ran nicely. I then uploaded the applet/servlet
pair onto a Unix webhost which supports JDK 1.4 and Servlets 2.3 via Tomcat
4.0.1. Here I have run into some major problems.

The applet stops running on any line using ImageIO methods. For example,
I am only using these 2 lines of ImageIO in my applet:

ImageIO.setCache(false);
ImageIO.write(buffImage, png, outputStream);

As it is, the Java console lists these errors for the ImageIO.setCache(false);
line:

sun.misc.ServiceConfigurationError: javax.imageio.spi.ImageTranscoderSpi:
http://www.imaginacard.com/IDraw/MET...anscoderSpi:2:

Illegal configuration-file syntax
at sun.misc.Service.fail(Service.java:129)
at sun.misc.Service.fail(Service.java:135)
at sun.misc.Service.parseLine(Service.java:157)
at sun.misc.Service.parse(Service.java:206)
at sun.misc.Service.access$100(Service.java:111)
at sun.misc.Service$LazyIterator.hasNext(Service.java:257)
at javax.imageio.spi.IIORegistry.registerApplicationClasspathSpis(IORegistry.java:173)

at javax.imageio.spi.IIORegistry.<init>(IIORegistry.java:113)
at javax.imageio.spi.IIORegistry.getDefaultInstance (IIORegistry.java:134)

at javax.imageio.ImageIO.<clinit>(ImageIO.java:44)
at IDrawApplet.saveImage(IDrawApplet.java:125)
at IDraw$FileAction.actionPerformed(IDraw.java:361)
........etc......

If I comment out that line, similar errors appear for the ImageIO.write method.
I have been trying to fix this problem for over a week and it has been to
no avail. I have read the ImageIO api over and over. I have tried to JAR
everything up and add in the meta-inf/services folder with the appropriate
files in it. And any documentation I find on ImageIO tells me how easy it
is to use. I do not have code in my applet telling it to look for any SPI's.
It's just doing it. I really don't understand how it worked through my
localhost Tomcat but it wont' work on the web server.

If anyone has any suggestions or explanations of these errors, it will be
so greatly appreciated.

Thank you for your time.

[Rob Abbe]

Kimberly,

Make sure the temp folder has been created. The script file may be specifying
a temp folder that does not exist. Check the script files that start tomcat
for more information. Some of the ImageIO classes need to cache to disk
and cannot do so if the tmp folder does not exist. On windows this would
probably not have been a problem.

Rob Abbe

"Kimberly Hendershot" <java..@127.0.0.1> wrote:
>
>Hi.
>
>I have an applet/servlet pair that communicate some images. The applet
is
>a paint-like program that allows the user to draw a picture. It then takes
>this picture and sends it via ImageIO to a servlet which can create a file
>on the server to save the image in .png format also using ImageIO.
>
>I developed and tested my applet/servlet pair using Tomcat 4.0.3 using my
>local machine as a host. Everything ran nicely. I then uploaded the applet/servlet
>pair onto a Unix webhost which supports JDK 1.4 and Servlets 2.3 via Tomcat
>4.0.1. Here I have run into some major problems.
>
>The applet stops running on any line using ImageIO methods. For example,
>I am only using these 2 lines of ImageIO in my applet:
>
>ImageIO.setCache(false);
>ImageIO.write(buffImage, png, outputStream);
>
>As it is, the Java console lists these errors for the ImageIO.setCache(false);
>line:
>
>sun.misc.ServiceConfigurationError: javax.imageio.spi.ImageTranscoderSpi:
>http://www.imaginacard.com/IDraw/MET...anscoderSpi:2:
>
>Illegal configuration-file syntax
>at sun.misc.Service.fail(Service.java:129)
>at sun.misc.Service.fail(Service.java:135)
>at sun.misc.Service.parseLine(Service.java:157)
>at sun.misc.Service.parse(Service.java:206)
>at sun.misc.Service.access$100(Service.java:111)
>at sun.misc.Service$LazyIterator.hasNext(Service.java:257)
>at javax.imageio.spi.IIORegistry.registerApplicationClasspathSpis(IORegistry.java:173)
>
>at javax.imageio.spi.IIORegistry.<init>(IIORegistry.java:113)
>at javax.imageio.spi.IIORegistry.getDefaultInstance (IIORegistry.java:134)
>
>at javax.imageio.ImageIO.<clinit>(ImageIO.java:44)
>at IDrawApplet.saveImage(IDrawApplet.java:125)
>at IDraw$FileAction.actionPerformed(IDraw.java:361)
>........etc......
>
>If I comment out that line, similar errors appear for the ImageIO.write
method.
> I have been trying to fix this problem for over a week and it has been
to
>no avail. I have read the ImageIO api over and over. I have tried to JAR
>everything up and add in the meta-inf/services folder with the appropriate
>files in it. And any documentation I find on ImageIO tells me how easy
it
>is to use. I do not have code in my applet telling it to look for any SPI's.
> It's just doing it. I really don't understand how it worked through my
>localhost Tomcat but it wont' work on the web server.
>
>If anyone has any suggestions or explanations of these errors, it will be
>so greatly appreciated.
>
>Thank you for your time.