org.apache.hadoop.hive.ql.udf.UDFWeekOfYear.java Source code

Introduction

Here is the source code for org.apache.hadoop.hive.ql.udf.UDFWeekOfYear.java

Source

/**
 * 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.hadoop.hive.ql.udf;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

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.hive.serde2.io.TimestampWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;

@description(name = "yearweek", value = "_FUNC_(date) - Returns the week of the year of the given date. A week "
        + "is considered to start on a Monday and week 1 is the first week with >3 days.", extended = "Examples:\n"
                + "  > SELECT _FUNC_('2008-02-20') FROM src LIMIT 1;\n" + "  8\n"
                + "  > SELECT _FUNC_('1980-12-31 12:59:59') FROM src LIMIT 1;\n" + "  1")
public class UDFWeekOfYear extends UDF {

    private static Log LOG = LogFactory.getLog(UDFWeekOfYear.class.getName());

    private SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
    private Calendar calendar = Calendar.getInstance();

    IntWritable result = new IntWritable();

    public UDFWeekOfYear() {
        calendar.setFirstDayOfWeek(Calendar.MONDAY);
        calendar.setMinimalDaysInFirstWeek(4);
    }

    public IntWritable evaluate(Text dateString) {
        if (dateString == null) {
            return null;
        }
        try {
            Date date = formatter.parse(dateString.toString());
            calendar.setTime(date);
            result.set(calendar.get(Calendar.WEEK_OF_YEAR));
            return result;
        } catch (ParseException e) {
            return null;
        }
    }

    public IntWritable evaluate(TimestampWritable t) {
        if (t == null) {
            return null;
        }

        calendar.setTime(t.getTimestamp());
        result.set(calendar.get(Calendar.WEEK_OF_YEAR));
        return result;
    }

}