GeoTools 2.6.5: Cannot get JMapFrame to work because of problem with processStylers

Question

I am trying to get JMapFrame to work to visualize some feature. Unfortunately I keep getting errors although this test app can be started. Toolbars etc. are shown.

18.02.2011 16:44:38 org.geotools.renderer.lite.StreamingRenderer paint

SEVERE: null

java.lang.NullPointerException
at org.geotools.renderer.lite.StreamingRenderer.processStylers(StreamingRenderer.java:1771)
at org.geotools.renderer.lite.StreamingRenderer.paint(StreamingRenderer.java:722)

(full stack trace here)

My source code is here. (And pom.xml here)

I assume the problem must be anywhere in "myStyle". Is there maybe a default style?

Answer 1

This one looks like the culprit:

Graphic graph = sb.createGraphic(null, new Mark[] { testMark }, null,
            sb.literalExpression(1), sb.attributeExpression("size"),
            sb.attributeExpression("rotation"));

you are creating graphic marker with a null graphic. I'm pretty sure you're hitting this issue (not an issue imo, more an error on the user side):

http://jira.codehaus.org/browse/GEOT-1772

Answer 2

From a quick scan it seems that you are trying to symbolize a line with a PointSymbolizer. The first thing to try would be to load a simple SLD file that you know works (build and test it in UDig). This would allow you be sure that it isn't a problem with your features. Then I'd add a logger and turn up the logging level before stepping through the program in a debugger to see what exactly is null.