WMS Server produces image/png everytime on jpeg/gif.. request. if image/png is requested gwc crashes

[osm-mapper]

to reproduce use wms: http://geodaten.service24.rlp.de/cgi-bin/wms.cgi?request=getcapabilities

try to load rlp:tk25 EPSG:4326 with OpenLayers: [png]

if you do so you fail with an error message (excerpt see below)

HTTP Status 500 -

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.springframework.web.util.NestedServletException?: Handler processing failed;

..
root cause

java.lang.NoSuchMethodError?:
..

NOTE: works with likar:likar and freedop:dop layer with jpeg!

[arneke]

The server responds to all PNG requests with image/png , Content-Length 0. The latter is correct, but then this is obviously not a valid image/png response.

So it's not clear to me why you are filing a bug here, how do you want GWC to act when this happens? I'm reducing the priority since the admin must configure GWC with a garbage input for this to occur.

Sample request:

http://geodaten.service24.rlp.de/cgi-bin/wms.cgi?SERVICE=WMS&REQUEST=GetMap&VERSION=1.1.1&LAYERS=rlp%3Atk25&EXCEPTIONS=application/vnd.ogc.se_xml&STYLES=&TRANSPARENT=TRUE&FORMAT=image/png&SRS=EPSG:3857&WIDTH=768&HEIGHT=768&BBOX=626172.135625001,6261721.356249999,1095801.237343751,6731350.457968749

Response:

HTTP/1.1 200 OK
Date: Tue, 02 Feb 2010 16:10:38 GMT
Server: Apache/2.2.3 (Linux/SUSE)
Content-Type: image/png
Content-Length: 0
Proxy-Connection: Keep-Alive
Connection: Keep-Alive

[osm-mapper]

if you request image/pneg it should work but there is another error. why?
with freedop and likar it works using image/jpeg.
so it seems not to be bogus data.

what do you think?

[arneke]

If you JPEG support, you need to change the next constructor-arg in geowebcache-servlet.xml,

<constructor-arg value="image/png,image/jpeg"/>

?

[osm-mapper]

yes i did. for the layers likar:likar and freedop:dop it works with jpeg.
but not for all other layers.
png does not work event with the both mentioned above.

one errortype is "got png requested jpeg", another error is the internal error (see ticket above)...

[osm-mapper]

will there be a fix/workaround?

[arneke]

There is a workaround, you can configure each layer manually and only select the formats supported by the backend for each layer. Alternatively you can use formatModifiers in geowebcache.xml (see documentation) to always use PNG as the input format (or JPEG, if that works), and GWC will internally convert to whatever format the client asked for.

I maintain it's much better to fix the WMS server.