ST_MultiLineString.java

package com.esri.hadoop.hive;

import java.util.List;

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.ql.exec.UDFArgumentLengthException;
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.Polyline;
import com.esri.core.geometry.ogc.OGCGeometry;

@Description(
	name = "ST_MultiLineString",
	value = "_FUNC_(array(x1, y1, x2, y2, ... ), array(x1, y1, x2, y2, ... ), ... ) - constructor for 2D multi line string\n"
	+ "_FUNC_('multilinestring( ... )') - constructor for 2D multi line string",
	extended = "Example:\n" +
	"  SELECT _FUNC_(array(1, 1, 2, 2), array(10, 10, 20, 20)) from src LIMIT 1;\n" + 
	"  SELECT _FUNC_('multilinestring ((1 1, 2 2), (10 10, 20 20))', 0) from src LIMIT 1;")
//@HivePdkUnitTests(
//	cases = {
//		@HivePdkUnitTest(
//			query = "select st_asjson(ST_MultiLineString(1, 1, 2, 2, 3, 3)) from onerow",
//			result = "{\"points\":[[1.0,1.0],[2.0,2.0],[3.0,3.0]]}"
//			),
//		@HivePdkUnitTest(
//			query = "select ST_Equals(ST_MultiLinestring('multilinestring ((2 4, 10 10), (20 20, 7 8))'), ST_GeomFromText('multilinestring ((2 4, 10 10), (20 20, 7 8))')) from onerow",
//			result = "true"
//			)
//		}
//)
public class ST_MultiLineString extends ST_Geometry {
	
	static final Log LOG = LogFactory.getLog(ST_MultiLineString.class.getName());
	
	// Number-pairs constructor
	public BytesWritable evaluate(List<DoubleWritable> ... multipaths) throws UDFArgumentLengthException{
		
		if (multipaths == null || multipaths.length == 0) {
			LogUtils.Log_ArgumentsNull(LOG);
			return null;
		}

		try {
			Polyline mPolyline = new Polyline();

			int arg_idx=0;
			for (List<DoubleWritable> multipath : multipaths)
				{
					if (multipath.size() %2 != 0){
						LogUtils.Log_VariableArgumentLengthXY(LOG, arg_idx);
						return null;
					}

					mPolyline.startPath(multipath.get(0).get(), multipath.get(1).get());

					for (int i=2;i<multipath.size();i+=2){
						mPolyline.lineTo(multipath.get(i).get(), multipath.get(i+1).get());
					}
					arg_idx++;
				}

			return GeometryUtils.geometryToEsriShapeBytesWritable(OGCGeometry.createFromEsriGeometry(mPolyline, null, true));
		} catch (Exception e) {
		    LogUtils.Log_InternalError(LOG, "ST_MultiLineString: " + e);
		    return null;
		}
	}

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

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

}