ST_LineString.java

package com.esri.hadoop.hive;

import java.util.ArrayList;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.serde2.io.DoubleWritable;
import org.apache.hadoop.io.BytesWritable;
import org.apache.hadoop.io.Text;


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


@Description(
	name = "ST_LineString",
	value = "_FUNC_(x, y, [x, y]*) - constructor for 2D line string\n" +
    "_FUNC_(array(x+), array(y+)) - constructor for 2D line string\n" +
    "_FUNC_(array(ST_Point(x,y)+)) - constructor for 2D line string\n" +
    "_FUNC_('linestring( ... )') - constructor for 2D line string",
	extended = "Example:\n" +
	"  SELECT _FUNC_(1, 1, 2, 2, 3, 3) from src LIMIT 1;\n" + 
	"  SELECT _FUNC_('linestring(1 1, 2 2, 3 3)') from src LIMIT 1;")
//@HivePdkUnitTests(
//	cases = {
//		@HivePdkUnitTest(
//			query = "select ST_GeometryType(ST_Linestring('linestring (10 10, 20 20)')) from onerow",
//			result = "ST_LINESTRING"
//			),
//		@HivePdkUnitTest(
//			query = "select ST_Equals(ST_Linestring('linestring (10 10, 20 20)'), ST_GeomFromText('linestring (10 10, 20 20)')) from onerow",
//			result = "true"
//			)
//		}
//	)

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

	// Number-pairs constructor
	public BytesWritable evaluate(DoubleWritable ... xyPairs) throws UDFArgumentException{
		
		if (xyPairs == null || xyPairs.length == 0 ||  xyPairs.length%2 != 0) {
			return null;
		}

		try {		
			Polyline linestring = new Polyline();
			linestring.startPath(xyPairs[0].get(), xyPairs[1].get());
		
			for (int i=2; i<xyPairs.length; i+=2) {
				linestring.lineTo(xyPairs[i].get(), xyPairs[i+1].get());
			}
		
			return GeometryUtils.geometryToEsriShapeBytesWritable(OGCGeometry.createFromEsriGeometry(linestring, null));
		} catch (Exception e) {
		    LogUtils.Log_InternalError(LOG, "ST_LineString: " + e);
		    return null;
		}
	}

	// constructor from arrays of X and Y coordinates
	public BytesWritable evaluate(ArrayList<DoubleWritable> xs, ArrayList<DoubleWritable> ys) throws UDFArgumentException {
		if (null == xs || null == ys || xs.size() == 0 || ys.size() == 0 || xs.size() != ys.size()) {
			return null;
		}

		try {		
			Polyline linestring = new Polyline();
		
			for (int ix=0; ix < xs.size(); ++ix) {
				DoubleWritable xdw = xs.get(ix), ydw = ys.get(ix);
				if (xdw == null || ydw == null) {
					LogUtils.Log_ArgumentsNull(LOG);
				}
				if (ix == 0) {
					linestring.startPath(xdw.get(), ydw.get());
				} else {
					linestring.lineTo(xdw.get(), ydw.get());
				}
			}
		
			return GeometryUtils.geometryToEsriShapeBytesWritable(OGCGeometry.createFromEsriGeometry(linestring, null));
		} catch (Exception e) {
		    LogUtils.Log_InternalError(LOG, "ST_LineString: " + e);
		    return null;
		}
	}

	// constructor from array of points
	public BytesWritable evaluate(ArrayList<BytesWritable> points) throws UDFArgumentException {
		if (null == points || points.size() == 0) {
			return null;
		}

		try {		
			Polyline linestring = new Polyline();
		
			for (int ix = 0; ix < points.size(); ++ix) {
				BytesWritable geomref = points.get(ix);
				OGCGeometry gcur = GeometryUtils.geometryFromEsriShape(geomref);
				if (gcur == null || GeometryUtils.getType(geomref) != GeometryUtils.OGCType.ST_POINT) {
					if (gcur == null)
						LogUtils.Log_ArgumentsNull(LOG);
					else
						LogUtils.Log_InvalidType(LOG, GeometryUtils.OGCType.ST_POINT, GeometryUtils.getType(geomref));
					return null;
				}
				if (ix == 0) {
					linestring.startPath((Point)gcur.getEsriGeometry());
				} else {
					linestring.lineTo((Point)gcur.getEsriGeometry());
				}
			}
		
			return GeometryUtils.geometryToEsriShapeBytesWritable(OGCGeometry.createFromEsriGeometry(linestring, null));
		} catch (Exception e) {
		    LogUtils.Log_InternalError(LOG, "ST_LineString: " + e);
		    return null;
		}
	}

	// WKT constructor - can use SetSRID on constructed multi-point
	public BytesWritable evaluate(Text wkwrap) throws UDFArgumentException {
		String wkt = wkwrap.toString();
		try {
			OGCGeometry ogcObj = OGCGeometry.fromText(wkt);
			ogcObj.setSpatialReference(null);
			if (ogcObj.geometryType().equals("LineString")) {
				return GeometryUtils.geometryToEsriShapeBytesWritable(ogcObj);
			} else {
				LogUtils.Log_InvalidType(LOG, GeometryUtils.OGCType.ST_LINESTRING, GeometryUtils.OGCType.UNKNOWN);
				return null;
			}

		} catch (Exception e) {  // IllegalArgumentException, GeometryException
			LogUtils.Log_InvalidText(LOG, wkt);
			return null;
		}
	}

}