Hive UDF’S addMonths

our project use hive 0.10 , and in the hiveql , we need use addMonths function builtin in hive-0.11.

so I write this udf and test.

java code:

package myudf;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Calendar;

import java.util.Date;

import org.apache.hadoop.hive.ql.exec.UDF;

public class addMonths extends UDF {

	final Calendar calendar = Calendar.getInstance();

	// String Year_month int numMonths

	// return date add

	public String evaluate(String _date, int numMonths) throws ParseException {

		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

		addMonth(sdf.parse(_date), numMonths);

		int month = calendar.get(Calendar.MONTH) + 1;

		String strmonth = String.valueOf(month > 9 ? month : "0" + month);

		String strYearMon = calendar.get(Calendar.YEAR) + strmonth;

		return strYearMon;

	}

	Calendar addMonth(Date d, int numMonths) {

		calendar.setTime(d);

		boolean lastDatOfMonth = isLastDayOfMonth(calendar);

		calendar.add(Calendar.MONTH, numMonths);

		if (lastDatOfMonth) {

			int maxDd = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);

			calendar.set(Calendar.DAY_OF_MONTH, maxDd);

		}

		return calendar;

	}

	boolean isLastDayOfMonth(Calendar cal) {

		int maxDd = cal.getActualMaximum(Calendar.DAY_OF_MONTH);

		int dd = cal.get(Calendar.DAY_OF_MONTH);

		return dd == maxDd;

	}

}

cd workspace and project folder. then

jar cvf myudf.jar ./

move to proper folder: mv myudf.jar /home/hadoop/jar/myudf.jar

add jar /home/hadoop/jar/myudf.jar;
create temporary function addMonths as "myudf.addMonths";
select addMonths('2012-03-03',2) as newdate, addMonths('2012-03-03',-2) as newdate2 from nums where num<2;

巴特西

Hive UDF’S addMonths

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