ST_AsGeoJson.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.Text;


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

@Description(
	name = "ST_AsGeoJSON",
	value = "_FUNC_(geometry) - return GeoJSON representation of geometry\n",
	extended = "Example:\n" +
	"  SELECT _FUNC_(ST_Point(1.0, 2.0)) from onerow; -- {\"type\":\"Point\", \"coordinates\":[1.0, 2.0]}\n" +
	"Note : \n" +
	" ST_AsGeoJSON outputs the _geometry_ contents but not _crs_.\n" +
	" ST_AsGeoJSON requires geometry-api-java version 1.1 or later.\n"
	)
//@HivePdkUnitTests(
//	cases = { 
//		@HivePdkUnitTest(
//			query = "select ST_AsGeoJSON(ST_point(1, 2))) from onerow",
//			result = "{\"type\":\"Point\", \"coordinates\":[1.0, 2.0]}"
//			),
//		@HivePdkUnitTest(
//			query = "SELECT ST_AsGeoJSON(ST_MultiLineString(array(1, 1, 2, 2, 3, 3), array(7,7, 8,8, 9,9))) from onerow",
//			result = "{\"type\":\"MultiLineString\",\"coordinates\":[[[1.0,1.0],[2.0,2.0],[3.0,3.0]],[[7.0,7.0],[8.0,8.0],[9.0,9.0]]]}"
//			),
//		@HivePdkUnitTest(
//			query = "SELECT ST_AsGeoJSON(ST_Polygon(1, 1, 1, 4, 4, 4, 4, 1)) from onerow",
//			result = "{\"type\":\"Polygon\",\"coordinates\":[[[1.0,1.0],[1.0,4.0],[4.0,4.0],[4.0,1.0],[1.0,1.0]]]}"
//			)
//		}
//	)

public class ST_AsGeoJson extends ST_Geometry {
	final Text resultText = new Text();
	static final Log LOG = LogFactory.getLog(ST_AsGeoJson.class.getName());

	public Text 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 {
			String outJson = ogcGeometry.asGeoJson();
			resultText.set(outJson);
			return resultText;
		} catch (Exception e) {
			LogUtils.Log_InternalError(LOG, "ST_AsGeoJSON: " + e);
			return null;
		}
	}

}