[Zoo-discuss] GSoC 2015 JGrasstools and Zoo-WPS

[Alexander Kmoch]

Hi Andrea,

thanks for the feedback :-) That's great to hear.

I am starting to prepare the student proposal / application here [1]. I 
am a little bit on vacation this week, but the proposal deadline is next 
Friday, if I understood correctly?

No Segfault for the NULL variables, the CGI / Apache scrolls most Java 
Exceptions into the Apache error logs, but the last but that doesn't 
work doesn't throw much of an helpful error message ...

MY first test with the simple Java Util Logging conf, works also only 
partially. I think I will have to take an in-depth look into the ZOO 
Java API with Gerald to understand which paths are read etc. AS of now I 
am mucking around with a mix of LD_LIBRARY_PATH, CLASSPATH and 
-Djava.library.path ... this all not really ideal yet, but I think I 
need to understand it better first.

Cheers,
Alex


[1] 
https://www.google-melange.com/gsoc/proposal/review/student/google/gsoc2015/allixender/5717271485874176
Hi Gerald,


Am 13.03.2015 um 01:53 schrieb zoo-discuss-request at lists.osgeo.org:
> Message: 6
> Date: Fri, 13 Mar 2015 09:22:35 +0100
> From: andrea antonello<andrea.antonello at gmail.com>
> Cc: ZOO-discuss<zoo-discuss at lists.osgeo.org>
> Subject: Re: [Zoo-discuss] GSoC 2015 JGrasstools and Zoo-WPS
>
> Hi Alexander,
> you know that the GOSC didn't start yet, right?:-)
>
> Jokes apart it is really a pleasure to find someone like you working
> on the GSOC.
>
>> >with some trickery and crude brute force I got an example from the zoo
>> >generator [1] to jgrasstools java wps [2] up and running.
>> >
>> >
>> >http://localhost/cgi-bin/zoo_loader.cgi?service=WPS&version=1.0.0&request=execute&identifier=RasterReprojectorBuilder&DataInputs=inRaster=/vol1/www/smart/tmp/dtm.asc;pCode=EPSG:3003;pInterpolation=NEAREST_NEIGHTBOUR;outRaster=/vol1/www/smart/tmp/dtm_out.tiff;pNorth=5110870.0;pSouth=5110830.0;pWest=1637140.0;pEast=1637190.0;pRows=4;pCols=5
>> >
>> >I am getting increasingly excited. There's certainly a long way to go, but
>> >it looks promising.
> I am excited as well, you already went further than I did when I gave
> it a quick try. Congratulations.
>
>> >Basically I had to collect all jar dependencies for the JGrasstools modules,
>> >add them to the CLASSPATH of the Generator.jar and it genertes the *.zcfg
>> >files. So I copy the *.zcfg into the ZOO cgi folder and als add all the libs
>> >to ZOO main.cfg for CLASSPATH.
>> >
>> >The input/output HashMap handling is wrong in the generator. But it's not as
>> >easy, I admit. But I took one of the examples, RasterReprojectWps", and
>> >modified it slightly to get the ZOO WPS inputs/output HashMaps translated
>> >into the OmsAccess thingy maps.
> This part should be possible to generate from the annotated code in
> the JGrasstools libs. So fun once, run everytime (or sort of :-)).
>
>> >I I also played with Logging. It's really
>> >difficult to debug. For the test I had to use all the input parameters,
>> >because otherwise the Oms Input parser would crash with
>> >NumberFormatExceptions (String "NULL" -> Double..)
> That is something we will have to take care. Do the java exceptions
> come to the surface or are they translated in beautiful C segmentation
> faults?:-)
>
>> >So the RasterReprojectWps actually works and creates a new raster (from the
>> >dtm.asc to a GeoTIFF), but the CGI-process does not finish properly after
>> >the raster creation ... I'll have to look in more depth, why?
>> >
>> >In the Apache2 error log: "... [cgi:error] malformed header from script
>> >'zoo_loader.cgi': Bad header: Finished."
>> >
>> >But I think this has some really good potential:-)  A lot of work should in
>> >fact go into the Java handling from ZOO side, and to make it easy to develop
>> >processes in Java and the JGrasstools/OMS3 Generator is pretty good already.
>> >But I bet there will be a lot of little mean obstacles to get it generalised
>> >:-)
> Yes, I hope it will be simple simple to generate tons of modules
> compatiible with Zoo.
>
> I think the one difficult thing might be to handle non local files,
> i.e. understand in which way to feed rasters and vectors to the
> processes. Apart of the use of WCS and WFS, it will be necessary to
> convert what comes from the service (through GDAL I think) into the
> modules.
>
>> >I'll see that I prepare a bit more of a detailed project description for the
>> >application. I'd be happy about some feedback.
> Yes, great, looking forward to it.
>
> Cheers,
> Andrea
>