/*
* 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.piggybank.evaluation.datetime;
import java.io.IOException;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.apache.pig.EvalFunc;
import org.apache.pig.FuncSpec;
import org.apache.pig.PigWarning;
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;
/**
* <dl>
* <dt><b>Syntax:</b></dt>
* <dd><code>int DiffDate(String yyyymmdd1, String yyyymmdd2)</code>.</dd>
* <dt><b>Input:</b></dt>
* <dd><code>date string in "yyyymmdd" format</code>.</dd>
* <dt><b>Output:</b></dt>
* <dd><code>(date1-date2) in days, can be negative</code>.</dd>
* </dl>
*/
public class DiffDate extends EvalFunc<Integer> {
static DateFormat df = new SimpleDateFormat("yyyyMMdd");
@Override
public Schema outputSchema(Schema input) {
try {
return new Schema(new Schema.FieldSchema(getSchemaName(this
.getClass().getName().toLowerCase(), input),
DataType.INTEGER));
} catch (Exception e) {
return null;
}
}
@Override
public Integer exec(Tuple input) throws IOException {
if (input.size()!=2) {
String msg = "DiffDate : Only 2 parameters are allowed.";
throw new IOException(msg);
}
String strDate1 = (String)input.get(0);
String strDate2 = (String)input.get(1);
if (input.get(0)==null || input.get(1)==null)
return null;
Date date1 = null;
Date date2 = null;
try {
date1 = df.parse(strDate1);
date2 = df.parse(strDate2);
} catch (ParseException e) {
String msg = "DiffDate : Parameters have to be string in 'yyyymmdd' format.";
warn(msg, PigWarning.UDF_WARNING_1);
return null;
}
return (int)((date1.getTime() - date2.getTime())/(1000*60*60*24));
}
@Override
public List<FuncSpec> getArgToFuncMapping() throws FrontendException {
List<FuncSpec> funcList = new ArrayList<FuncSpec>();
Schema s = new Schema();
s.add(new Schema.FieldSchema(null, DataType.CHARARRAY));
s.add(new Schema.FieldSchema(null, DataType.CHARARRAY));
funcList.add(new FuncSpec(this.getClass().getName(), s));
return funcList;
}
}