UDF：时间加减

package com.adtime.udf.main; import java.sql.Date; import java.text.SimpleDateFormat; import org.apache.commons.lang.StringUtils; import org.apache.hadoop.hive.ql.exec.UDF; /** * @author leen * @date Mar 13, 2017 10:29:54 AM * @parameter input:2017-01-05 19:34:17 return:2017-01-05 20:34:17 的时间戳 */ public class UdfReturnOneHourLater extends UDF { public String evaluate (String datetime,String add) throws Exception { //对于日期为null / "" / " " 返回null if (StringUtils.isBlank(datetime) || (datetime.length() != 19 && datetime.length() != 21)){ return null; } if(StringUtils.isBlank(add)){ //添加的时间小时长度的不能为空 return null; } if(datetime.length() == 21){ datetime = datetime.substring(0, 19); } //将字符串转化为时间戳 SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); Long date1 = df.parse(datetime).getTime(); //add转为Long类型 Double addDouble = Double.parseDouble(add); //将时间add加上去 long addDate = (long) (date1 + 1000*60*60*addDouble); //将时间戳转为时间格式：yyyy-MM-dd hh:mm:ss Date date2 = new Date(addDate); String returnDate = df.format(date2).toString(); //返回更新之后的时间戳的字符串 return returnDate; } public static void main(String[] args) throws Exception { UdfReturnOneHourLater uu = new UdfReturnOneHourLater(); System.out.println(uu.evaluate("2017-01-05 19:34:19.0", "-0.5"));//2017-01-05 19:04:19 System.out.println(uu.evaluate("2017-01-05 19:34:19", "0.5"));//2017-01-05 20:04:19 } }