QGIS + WPS client: Error reported by 52°North WPS

classic Classic list List threaded Threaded
9 messages Options
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

QGIS + WPS client: Error reported by 52°North WPS

Jan Slegr
Hi,

I installed this configuration (everything on Windows)
* Java 1.7 64bit
* Tomcat 7
* 52° North WPS 3.3.1
* QGIS 2.12.1 (Lyon)
* WPS Client for QGIS 2.1.1

The server works well, I am able to use "52°North WPS form client" to send the request (e.g. jtsconvexhull_request.xml) and a result is returned correctly. I am also to connect to admin pages.

If I connect to the server from QGIS, the available services is displayed, but if I choose e.g. "org.n52.wps.server.algorithm.JTSConvexHullAlgorithm", this error is reported: Invalid Parameter Value: Specified process identifier does not exist. (and Java stack is displayed).

In Tomcat localhost_access_log I found:
"GET /wps/WebProcessingService?Request=GetCapabilities&Service=WPS&Request=DescribeProcess&Identifier=org.n52.wps.server.algorithm.JTSConvexHullAlgorithm&Service=WPS&Version=1.0.0 HTTP/1.1"
"POST /wps/WebProcessingService?Request=DescribeProcess&Identifier=org.n52.wps.server.algorithm.JTSConvexHullAlgorithm&Service=WPS& HTTP/1.1"

The POST looks strange to me, because it ends with & and no Version parameter is used, but I am not sure if it's not cut by Tomcat loging.

Before I will start to debug the communication between QGIS WPS client and 52°North WPS server, I'd like to ask if somebody have met the same problem or have an idea what to check / correct at first.

With regards,

  Jan
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: QGIS + WPS client: Error reported by 52°North WPS

BenjaminPross
Hi Jan,

I just tried out your setup. I can connect to the process, so I guess you'll have to debug..
Let us know if you found the issue or have any other questions.

Cheers,

Benjamin
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: QGIS + WPS client: Error reported by 52°North WPS

Jan Slegr
Hi Benjamin,

thanks for your answer.

It's weird, my installation works better today (still thinking what changes I did as the last ;-): After I choose an operation from the list, a dialog with operation parameters is displayed, so I am able to choose what layer will be used as the operation input.

Now I am receiving another error (see below), but it's better, because now I know the server receives the data.

Reported error (org.n52.wps.server.algorithm.convexhull.ConvexHullAlgorithm process used):

org.n52.wps.server.ExceptionReport: Error occured, while XML parsing at org.n52.wps.server.request.InputHandler.parseComplexValue(InputHandler.java:576) at org.n52.wps.server.request.InputHandler.handleComplexData(InputHandler.java:518) at org.n52.wps.server.request.InputHandler.<init>(InputHandler.java:157) at org.n52.wps.server.request.InputHandler.<init>(InputHandler.java:88) at org.n52.wps.server.request.InputHandler$Builder.build(InputHandler.java:119) at org.n52.wps.server.request.ExecuteRequest.call(ExecuteRequest.java:662) at org.n52.wps.server.request.ExecuteRequest.call(ExecuteRequest.java:92) at java.util.concurrent.FutureTask.run(Unknown Source) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source) Caused by: java.lang.IllegalArgumentException: org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 2; Reference is not allowed in prolog. at org.n52.wps.io.datahandler.parser.GML3BasicParser.determineFeatureTypeSchema(GML3BasicParser.java:309) at org.n52.wps.io.datahandler.parser.GML3BasicParser.parseFeatureCollection(GML3BasicParser.java:150) at org.n52.wps.io.datahandler.parser.GML3BasicParser.parseXML(GML3BasicParser.java:135) at org.n52.wps.io.datahandler.parser.GML3BasicParser.parse(GML3BasicParser.java:120) at org.n52.wps.io.datahandler.parser.GML3BasicParser.parse(GML3BasicParser.java:96) at org.n52.wps.server.request.InputHandler.parseComplexValue(InputHandler.java:574) ... 10 more Caused by: org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 2; Reference is not allowed in prolog. at org.apache.xerces.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source) at org.apache.xerces.util.ErrorHandlerWrapper.fatalError(Unknown Source) at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source) at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source) at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source) at org.apache.xerces.impl.XMLScanner.reportFatalError(Unknown Source) at org.apache.xerces.impl.XMLDocumentScannerImpl$PrologDispatcher.dispatch(Unknown Source) at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source) at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source) at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source) at org.apache.xerces.parsers.XMLParser.parse(Unknown Source) at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source) at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source) at org.apache.xerces.jaxp.SAXParserImpl.parse(Unknown Source) at javax.xml.parsers.SAXParser.parse(Unknown Source) at org.n52.wps.io.datahandler.parser.GML3BasicParser.determineFeatureTypeSchema(GML3BasicParser.java:299) ... 15 more
org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 2; Reference is not allowed in prolog.

BTW I also tried to use offical demo server (http://geoprocessing.demo.52north.org/52n-wps-webapp-3.3.1-gt/) but the same problem is reported.

With regards,

  Jan
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: QGIS + WPS client: Error reported by 52°North WPS

BenjaminPross
I found this old post:

http://geoprocessing.forum.52north.org/Error-parsing-GML3-using-QGIS-WPS-plugin-td4026113.html#a4026116

There I promised to search for a solution for this issue but I never did.. Somehow I still don't think it is correct to wrap XML in CDATA elements, so this should be fixed on client side, I guess..
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: QGIS + WPS client: Error reported by 52°North WPS

Jan Slegr
Thanks a lot, I will check the thread you mentioned and will play with the configuration. The thread is over a year old, so I guess some changes in GML format used were implemented (suppose now it's about GML 3.2.1 not 3.1.1, but not sure).

I guess if I use WPS with geotools, the modification should not be done in wps_config.xml but in wps_config_geotools.xml?

Without deep knowledge of WPS standard, I agree with you to encapsulate data into CDATA element is maybe formally correct from XML format perspective, but not good as the solution.

Regards,

  Jan
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: QGIS + WPS client: Error reported by 52°North WPS

Jan Slegr
Ok, after removing GML2BasicParser parser and changing GML3BasicParser to

<Parser name="GML3BasicParser" className="org.n52.wps.io.datahandler.parser.GML3BasicParser" active="true">
  <Format mimetype="text/xml" schema="http://schemas.opengis.net/gml/3.1.1/base/gml.xsd"/>
</Parser>

the error message changed to

JAVA_RootCause: org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 2; Reference is not allowed in prolog.

I will study what this SAX eception can be caused.

Regards,

  Jan
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: QGIS + WPS client: Error reported by 52°North WPS

Joerg
Hi Jan

I have the same issue. Did you find a solution for fixing the problem?

Regards,
Joerg
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: QGIS + WPS client: Error reported by 52°North WPS

Jachym Cepicky
In reply to this post by Jan Slegr
hi Jan,

without knowing much details about your specific case, I can confirm, I was facing issues with the QGIS client, some of the produced XMLs were not generated correctly, as well as number of specified input formats is rather small. and reporting the bug and provide patch is complicated too, since in the README file you are pointed to official QGIS bug tracker, which is to be used for the QGIS-core exclusively

i do not know much about 52north, but if you need some help regarding WPS in general or maybe some help with the QGIS client, I could probably  come along and try to help on the spot

Jáchym

On Thu, Dec 17, 2015, 12:25 Jan Slegr <[hidden email]> wrote:
Hi,

I installed this configuration (everything on Windows)
* Java 1.7 64bit
* Tomcat 7
* 52° North WPS 3.3.1
* QGIS 2.12.1 (Lyon)
* WPS Client for QGIS 2.1.1

The server works well, I am able to use "52°North WPS form client" to send
the request (e.g. jtsconvexhull_request.xml) and a result is returned
correctly. I am also to connect to admin pages.

If I connect to the server from QGIS, the available services is displayed,
but if I choose e.g. "org.n52.wps.server.algorithm.JTSConvexHullAlgorithm",
this error is reported: Invalid Parameter Value: Specified process
identifier does not exist. (and Java stack is displayed).

In Tomcat localhost_access_log I found:
"GET
/wps/WebProcessingService?Request=GetCapabilities&Service=WPS&Request=DescribeProcess&Identifier=org.n52.wps.server.algorithm.JTSConvexHullAlgorithm&Service=WPS&Version=1.0.0
HTTP/1.1"
"POST
/wps/WebProcessingService?Request=DescribeProcess&Identifier=org.n52.wps.server.algorithm.JTSConvexHullAlgorithm&Service=WPS&
HTTP/1.1"

The POST looks strange to me, because it ends with & and no Version
parameter is used, but I am not sure if it's not cut by Tomcat loging.

Before I will start to debug the communication between QGIS WPS client and
52°North WPS server, I'd like to ask if somebody have met the same problem
or have an idea what to check / correct at first.

With regards,

  Jan




--
View this message in context: http://geoprocessing.forum.52north.org/QGIS-WPS-client-Error-reported-by-52-North-WPS-tp4026143.html
Sent from the 52° North - Geoprocessing Community Forum mailing list archive at Nabble.com.
_______________________________________________
Geoprocessingservices mailing list
[hidden email]
http://list.52north.org/mailman/listinfo/geoprocessingservices
http://geoprocessing.forum.52north.org
Please respect our mailing list guidelines:
http://52north.org/resources/mailing-lists-and-forums/guidelines

_______________________________________________
Geoprocessingservices mailing list
[hidden email]
http://list.52north.org/mailman/listinfo/geoprocessingservices
http://geoprocessing.forum.52north.org
Please respect our mailing list guidelines:
http://52north.org/resources/mailing-lists-and-forums/guidelines
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: QGIS + WPS client: Error reported by 52°North WPS

BenjaminPross
In reply to this post by Joerg
Hello Joerg,

There is a new WPS release (3.5.0) that should fix the issues with the QGIS client. Basically the XML parsing was made more robust, so it can handle the QGIS requests.
Maybe you can give it a try.

Cheers,

Benjamin
Loading...