ST_NumGeometries.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 org.apache.hadoop.io.IntWritable;

import com.esri.core.geometry.ogc.OGCGeometry;
import com.esri.core.geometry.ogc.OGCMultiPoint;
import com.esri.core.geometry.ogc.OGCMultiLineString;
import com.esri.core.geometry.ogc.OGCMultiPolygon;

@Description(
	name = "ST_NumGeometries",
	value = "_FUNC_(ST_GeometryCollection) - return the number of geometries in the geometry collection",
	extended = "Example:\n"
	+ "  SELECT _FUNC_(ST_GeomFromText('multipoint ((10 40), (40 30), (20 20), (30 10))')) FROM src LIMIT 1;  -- 4\n"
	+ "  SELECT _FUNC_(ST_GeomFromText('multilinestring ((2 4, 10 10), (20 20, 7 8))')) FROM src LIMIT 1;  -- 2\n"
	)

public class ST_NumGeometries extends ST_GeometryAccessor {
	final IntWritable resultInt = new IntWritable();
	static final Log LOG = LogFactory.getLog(ST_NumGeometries.class.getName());

	public IntWritable evaluate(BytesWritable geomref) {
		if (geomref == null || geomref.getLength() == 0) {
			LogUtils.Log_ArgumentsNull(LOG);
			return null;
		}

		OGCGeometry ogcGeometry = GeometryUtils.geometryFromEsriShape(geomref);
		if (ogcGeometry == null){
			LogUtils.Log_ArgumentsNull(LOG);
			return null;
		}

		try {
			GeometryUtils.OGCType ogcType = GeometryUtils.getType(geomref);
			switch(ogcType) {
			case ST_POINT:
				LogUtils.Log_InvalidType(LOG, GeometryUtils.OGCType.ST_MULTIPOINT, ogcType);
				return null;
			case ST_LINESTRING:
				LogUtils.Log_InvalidType(LOG, GeometryUtils.OGCType.ST_MULTILINESTRING, ogcType);
				return null;
			case ST_POLYGON:
				LogUtils.Log_InvalidType(LOG, GeometryUtils.OGCType.ST_MULTIPOLYGON, ogcType);
				return null;
			case ST_MULTIPOINT:
				resultInt.set(((OGCMultiPoint)ogcGeometry).numGeometries());
				break;
			case ST_MULTILINESTRING:
				resultInt.set(((OGCMultiLineString)ogcGeometry).numGeometries());
				break;
			case ST_MULTIPOLYGON:
				resultInt.set(((OGCMultiPolygon)ogcGeometry).numGeometries());
				break;
			}
		} catch (ClassCastException cce) {  // single vs Multi geometry type
			resultInt.set(1);
		} catch (Exception e) {
			LogUtils.Log_InternalError(LOG, "ST_NumGeometries: " + e);
			return null;
		}
		return resultInt;
	}

}