Oracle spatial - check polygon vertices counter clockwise

Question

I need to import a huge number of polygons from a third party (as a csv file- array of x,y's). I have to check whether the polygon vertices are in clockwise or counter clockwise, finally i have to convert it into counter clockwise and store it in the oracle spatial table as sdo geometry.

I am not able to find any oracle spatial java API to check the array of vertices and convert it into counter clockwise. I tried the same question in oracle spatial forum, but they said no API for this.

do you have ever worked on this oracle spatial java API, any other thoughts. ( i have found some methods to validate the ring rotation "http://paulbourke.net/geometry/clockwise/index.html", but if it is from oracle it will be good to implement).

• Mapperz: Run SDO_GEOM.VALIDATE_GEOMETRY_WITH_CONTEXT - docs.oracle.com/cd/B10501_01/appdev.920/a96630/… returns The context of the error (the coordinate, edge, or ring that causes the geometry to be invalid)
• Vadivelan Palanichamy: I would be good, if it is in java api.

Answer 1

EXECUTE SDO_MIGRATE.TO_CURRENT('YOUR_TABLE'); Should correct the orientation of your polygons (10G r2)

• Vadivelan Palanichamy: I have got the logic to check the polygon geometry before storing into database community.topcoder.com/…

Answer 2

I know this question is ancient, but for anyone else wondering about this scenario:

Maybe the steps would be:

1. In a query, validate the polygons using sdo_geom.validate_geometry_with_context().
   • Related: Look up SDO_GEOMETRY validation error code using SQL
2. For the polygons that have problems, use the rectify_geometry() function to fix them (within a query).
3. Store all the polygons (including the rectified polygons) in the final Oracle table as SDO_GEOMETRY.

That's just a guess. I'm not an Oracle Spatial expert.

I know the question asked for a Java solution, and this proposed solution isn't Java. But maybe it's possible to put the data in a temporary db table somewhere, run the SQL queries on it as I suggested, and then INSERT the resulting data into the final table. Maybe it's possible to run those SQL queries from Java code? (execute SQL from within Java)

Or maybe there is a way to use some sort of Oracle DB tool to load the CSV into a temporary table, and then proceed from there?

Or maybe just use a GIS tool like ArcGIS Pro to import the CSV into a temporary Oracle/SDO_GEOMETRY table. Maybe ArcGIS Pro would automatically rectify any problem polygons. Now that I think about it more, I think I like this idea best. Rectifying and loading GIS data is what GIS tools like ArcGIS Pro are good at.

Just some uneducated thoughts.