Java tutorial
/** * Tencent is pleased to support the open source community by making TDW available. * Copyright (C) 2014 THL A29 Limited, a Tencent company. All rights reserved. * Licensed under the Apache License, Version 2.0 (the "License"); you may not use * this file except in compliance with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software distributed * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS * OF ANY KIND, either express or implied. See the License for the specific language governing * permissions and limitations under the License. */ package org.apache.hadoop.hive.ql.udf; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; import java.util.TimeZone; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.hive.ql.exec.UDF; import org.apache.hadoop.hive.ql.exec.description; import org.apache.hadoop.io.Text; import org.apache.hadoop.io.IntWritable; @description(name = "tz_offset", value = "_FUNC_(timezone ) - returns the time zone offset of a value", extended = "Example:\n " + " > SELECT _FUNC_('US/Michigan') FROM src LIMIT 1;\n" + "-05:00") public class UDFTz_Offset extends UDF { private static Log LOG = LogFactory.getLog(UDFTz_Offset.class.getName()); private SimpleDateFormat formatter = new SimpleDateFormat("h:mm"); Text result = new Text(); public UDFTz_Offset() { } public Text evaluate(Text timezone) { if (timezone == null) { return null; } try { String ttt = timezone.toString(); if (ttt.endsWith("00") && (!ttt.startsWith("GMT"))) { ttt = "GMT" + ttt; } TimeZone tz = TimeZone.getTimeZone(ttt); Calendar calendar = Calendar.getInstance(tz); int off = calendar.get(Calendar.ZONE_OFFSET); off = off / 3600000; String ooo = String.format("%1$+03d", off); ooo = ooo + ":00"; result.set(ooo); return result; } catch (Exception e) { return null; } } }