ST_SymmetricDiff.java

package com.esri.hadoop.hive;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.io.BytesWritable;


import com.esri.core.geometry.ogc.OGCGeometry;

@Description(
	name = "ST_SymmetricDiff",
	value = "_FUNC_(ST_Geometry1, ST_Geometry2) - return the symmetric difference between ST_Geometry1 & ST_Geometry2",
	extended = "Examples:\n"
	+ " > SELECT ST_AsText(_FUNC_(ST_LineString('linestring(0 2, 2 2)'), ST_LineString('linestring(1 2, 3 2)'))) FROM onerow; \n"
	+ " MULTILINESTRING((0 2, 1 2), (2 2, 3 2))\n"
	+ " > SELECT ST_AsText(_FUNC_(ST_SymmetricDiff(ST_Polygon('polygon((0 0, 2 0, 2 2, 0 2, 0 0))'), ST_Polygon('polygon((1 1, 3 1, 3 3, 1 3, 1 1))'))) from onerow;\n"
	+ " MULTIPOLYGON (((0 0, 2 0, 2 1, 1 1, 1 2, 0 2, 0 0)), ((3 1, 3 3, 1 3, 1 2, 2 2, 2 1, 3 1)))\n" 
	)
//@HivePdkUnitTests(
//	cases = {
//		@HivePdkUnitTest(
//			query = "SELECT ST_Equals(ST_SymmetricDiff(ST_LineString('linestring(0 2, 2 2)'), ST_LineString('linestring(1 2, 3 2)')), ST_GeomFromText('multilinestring((0 2, 1 2), (2 2, 3 2))')) FROM onerow",
//			result = "true"
//			),
//		@HivePdkUnitTest(
//			query = "SELECT ST_Equals(ST_SymmetricDiff(ST_Polygon('polygon((0 0, 2 0, 2 2, 0 2, 0 0))'), ST_Polygon('polygon((1 1, 3 1, 3 3, 1 3, 1 1))')), ST_MultiPolygon('multipolygon(((0 0, 2 0, 2 1, 1 1, 1 2, 0 2, 0 0)), ((3 1, 3 3, 1 3, 1 2, 2 2, 2 1, 3 1)))')) FROM onerow",
//			result = "true"
//			),
//		@HivePdkUnitTest(
//			query = "SELECT ST_SymmetricDiff(ST_Point(0,0), null) from onerow",
//			result = "null"
//			)
//		}
//	)

public class ST_SymmetricDiff extends ST_GeometryProcessing {
	
	static final Log LOG = LogFactory.getLog(ST_SymmetricDiff.class.getName());

	public BytesWritable evaluate(BytesWritable geometryref1, BytesWritable geometryref2)
	{
		if (geometryref1 == null || geometryref2 == null ||
		    geometryref1.getLength() == 0 || geometryref2.getLength() == 0) {
			LogUtils.Log_ArgumentsNull(LOG);
			return null;
		}
		
		if (!GeometryUtils.compareSpatialReferences(geometryref1, geometryref2)) {
			LogUtils.Log_SRIDMismatch(LOG, geometryref1, geometryref2);
			return null;
		}

		OGCGeometry ogcGeom1 = GeometryUtils.geometryFromEsriShape(geometryref1);
		OGCGeometry ogcGeom2 = GeometryUtils.geometryFromEsriShape(geometryref2);
		if (ogcGeom1 == null || ogcGeom2 == null){
			LogUtils.Log_ArgumentsNull(LOG);
			return null;
		}
		
		try {
			OGCGeometry diffGeometry = ogcGeom1.symDifference(ogcGeom2);
			return GeometryUtils.geometryToEsriShapeBytesWritable(diffGeometry);
		} catch (Exception e) {
		    LogUtils.Log_InternalError(LOG, "ST_SymmetricDiff: " + e);
		    return null;
		}
	}

}