| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.pig.builtin; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.pig.EvalFunc; |
| import org.apache.pig.FuncSpec; |
| import org.apache.pig.data.DataType; |
| import org.apache.pig.data.Tuple; |
| import org.apache.pig.impl.logicalLayer.FrontendException; |
| import org.apache.pig.impl.logicalLayer.schema.Schema; |
| import org.joda.time.DateTime; |
| |
| /** |
| * GetHour extracts the hour of a day from a DateTime object. |
| * <ul> |
| * <li>Jodatime: http://joda-time.sourceforge.net/</li> |
| * <li>ISO8601 Date Format: http://en.wikipedia.org/wiki/ISO_8601</li> |
| * </ul> |
| * <br /> |
| * <pre> |
| * Example usage: |
| * |
| * ISOin = LOAD 'test.tsv' USING PigStorage('\t') AS (dt:datetime); |
| * |
| * DESCRIBE ISOin; |
| * ISOin: {dt: datetime} |
| * |
| * DUMP ISOin; |
| * |
| * (2009-01-07T01:07:01.071Z) |
| * (2008-02-06T02:06:02.062Z) |
| * (2007-03-05T03:05:03.053Z) |
| * ... |
| * |
| * truncated = FOREACH ISO in GENERATE GetYear(dt) AS year, |
| * GetMonth(dt) as month, |
| * GetWeek(dt) as week, |
| * GetWeekYear(dt) as weekyear, |
| * GetDay(dt) AS day, |
| * GetHour(dt) AS hour, |
| * GetMinute(dt) AS min, |
| * GetSecond(dt) AS sec; |
| * GetMillSecond(dt) AS milli; |
| * |
| * DESCRIBE truncated; |
| * truncated: {year: int,month: int,week: int,weekyear: int,day: int,hour: int,min: int,sec: int,milli: int} |
| * |
| * DUMP truncated; |
| * (2009,1,2,2009,7,1,7,1,71) |
| * (2008,2,6,2008,6,2,6,2,62) |
| * (2007,3,10,2007,5,3,5,3,53) |
| * </pre> |
| */ |
| public class GetHour extends EvalFunc<Integer> { |
| |
| @Override |
| public Integer exec(Tuple input) throws IOException { |
| if (input == null || input.size() < 1 || input.get(0) == null) { |
| return null; |
| } |
| |
| return ((DateTime) input.get(0)).getHourOfDay(); |
| } |
| |
| @Override |
| public Schema outputSchema(Schema input) { |
| return new Schema(new Schema.FieldSchema(getSchemaName(this.getClass().getName().toLowerCase(), input), DataType.INTEGER)); |
| } |
| |
| @Override |
| public List<FuncSpec> getArgToFuncMapping() throws FrontendException { |
| List<FuncSpec> funcList = new ArrayList<FuncSpec>(); |
| funcList.add(new FuncSpec(this.getClass().getName(), new Schema(new Schema.FieldSchema(null, DataType.DATETIME)))); |
| |
| return funcList; |
| } |
| |
| @Override |
| public boolean allowCompileTimeCalculation() { |
| return true; |
| } |
| } |