UDF函数:返回输入日期的月末日期

需求：输入日期，返回当前日期的月末日期

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.io.Text;
/**
 * 输入日期，返回当月的月末的日期
 */
public class UDFLastDay extends UDF
{
    public static  String evaluate(String Date)
            throws ParseException
    {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
        SimpleDateFormat sdf1 = new SimpleDateFormat("yyyy-MM-dd");
        Calendar cal = Calendar.getInstance();
        Date date = null;
        try
        {
            date = sdf.parse(Date.replace("-", ""));
        }
        catch (ParseException e)
        {
            e.printStackTrace();
        }
        cal.setTime(date);
        cal.set(5, cal.getActualMaximum(5));

        return sdf1.format(cal.getTime());
    }
    public static void main(String[] args) throws Exception
    {
        UDFLastDay o = new UDFLastDay();

        System.out.println(o.evaluate("2000-02-22"));  //闰年的二月
        System.out.println(o.evaluate("2018-02-22"));  //非闰年的二月
        System.out.println(o.evaluate("20181022"));
        System.out.println(o.evaluate("20180922"));
    }
}

输出结果如下：
2000-02-29
2018-02-28
2018-10-31
2018-09-30