Hello

At 05/06/2003 13:23 -0400, William L. Thomson Jr. wrote:

>I am trying to track down a problem I am having with a servlet that
>servers pictures from Blob columns in a Firebird DB.
>
>The same servlet does not generate the same results on different
>platforms.
>
>The db server is the same for all machines. My DB server currently is a
>RH 8 box, with a 2.4 kernel, and UTF8 as it's default character set.
>
>My DB's default character set is ASCII. I choose that a long time ago
>and plan to pump out the data into a UTF8 db. Hopefully that day is not
>today.
>
>The servlet only produces the expected output on one of my machines.
>That machines is running a 2.2 kernel, and the OS is based on RH 6.2.
>It's default character set is ISO8859-1.
>
>Now I have two other machines that I have the same servlet talking to
>the same db server, yet the output of the servlet differs.
>
>One of the machines is a RH 9 box, with a 2.4 kernel and it's default
>character set is UTF8.
>
>Another machine is a Win2k machine. Not sure on default character set,
>but I think it is UTF8?
>
>Now one all three machines I am running the latest version of Tomcat,
>JDK from Sun, and JayBird.
>
>I have spent some time on this and for the life of me can't find the
>problem. I have played around with the servlet itself, but I do not
>think that is the problem.
>
>I think the problem is created during the conversion of character sets.
>I have tried to play around with the lc_ctype, but it seems to have no
>effect.
>
>I do not believe this is a Tomcat issue, maybe JDK? I do not think it's
>a JayBird or Firebird problem. I do think I am not doing something
>correctly with regard to Firebird, Jaybird and character sets.
>
>Here is the main part of the servlet
>
>if(result_set.next()) {
> //ServletOutputStream sos = response.getOutputStream();
> //sos.println(result_set.getString(1));
> //sos.close();
> PrintWriter print_writer = response.getWriter();
> response.setContentType("image/jpeg");
>response.setContentLength(result_set.getString(1).length());
> print_writer.print(result_set.getString(1));
> print_writer.close();
>}
>
>Now when I use ServletOutputStream, it sort of confirms my character set
>theory. Since I get errors like
>
>java.io.CharConversionException: Not an ISO 8859-1 character: �
>
>Now if I change the character set of the browser to UTF8 I get the
>following
>
>java.io.CharConversionException: Not an ISO 8859-1 character: �
>
>That last char shows up as a box on Win2k.
>
>Now on both my Linux machines I am also using Apache. However on the
>Windows machines I am only using Tomcat.
>
>So my problem appears to be with character set conversions. I assume
>between the output from Jaybird and the viewers browser? Possible having
>to do with Tomcat?
>
>Here are links to the output of the servlet on different machines when
>using PrintWriter.
>
>Here is a picture from the servlet on my production server
>http://www.obsidian-studios.com/Picture1.jpg
>
>Here is that same picture from my development machine and win2k machine.
>http://www.obsidian-studios.com/Picture.jpg
>
>It appears the pictures are off by one byte. However if you look at the
>two files with a hex editor, their contents are quite different. More
>than just a lack of a byte. Thus the result being a crappy picture.
>
>Any suggestions on how I might solve this problem?
>
>I am sort of stuck, and really need assistance. Thank you.

I you are talking about images, then your BLOB must be sub_type 0 and
not the driver nor the engine should do any character conversion.

Please confirm the sub_type you are using.

Regards
Blas Rodriguez Somoza