odps编写UDF的实现

问题

      尝试写一个UDF，参数支持输入x，y与一个Polygon，返回结果是(x,y)是否在输入的Geometry之内？

环境

1. eclipse
2. odps 插件
3. jts包：jts-1.8.jar

 解法

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.aliyun.odps.udf.UDF;
import com.vividsolutions.jts.geom.*;
import com.vividsolutions.jts.io.ParseException;
import com.vividsolutions.jts.io.WKTReader;

/**
 * 
 * @author xingxing.dxx
 *
 */
public class WithinUDF extends UDF {
	
	private GeometryFactory geometryFactory = new GeometryFactory();
	
	/*private Logger LOGGER = LoggerFactory.getLogger(WithinUDF.class);*/

	/**
	 * 判断以x,y为坐标的点point(x,y)是否在geometry表示的Polygon中
	 * @param x 
	 * @param y
	 * @param geometry wkt格式
	 * @return 
	 */
	public Boolean evaluate(Double x, Double y, String geometry){

		Coordinate coord = new Coordinate(x, y);
		Point point = geometryFactory.createPoint(coord);

		WKTReader reader = new WKTReader(geometryFactory);
		try {
			Polygon polygon = (Polygon) reader.read(geometry);
			return point.within(polygon);
		} catch (ParseException e) {
			/*LOGGER.error("geometry 格式错误",e);*/
			throw new RuntimeException(e.getMessage());
		}
	}

}

测试步骤

1. 新建表

odpscmd
create table dual(x double,y double,geometry string);

　   2.  准备数据（dual.txt）,内容如下：

5;5;POLYGON((0 0, 10 0, 10 10, 0 10,0 0))

　　3.  上传

tunnel u -fd ';' dual.txt project名称.dual; //列之间按照";"分割

　　4.  运行

 true

　　可以看到结果为true，执行成功