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

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

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/**
* 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.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

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.IntWritable;
import org.apache.hadoop.io.Text;

@description(name = "last_day", value = "_FUNC_(date) - Returns the last day of the month based on a date value", extended = "date is a string in the format of 'yyyy-MM-dd'.\n"
        + "Example:\n " + "  > SELECT _FUNC_('2003/03/15') FROM src LIMIT 1;\n" + "  31")
public class UDFLAST_DAY extends UDF {

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

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

    IntWritable result = new IntWritable();

    public UDFLAST_DAY() {
    }

    public IntWritable evaluate(Text dateString) {

        if (dateString == null) {
            return null;
        }

        try {
            Date date = formatter.parse(dateString.toString());
            calendar.setTime(date);

            if (calendar.get(Calendar.ERA) == GregorianCalendar.BC)
                return null;
            int xxh = calendar.get(Calendar.YEAR);
            if ((xxh < 1900) || (xxh > 9999))
                return null;

            int maxDay = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
            result.set(maxDay);
            return result;
        } catch (ParseException e) {
            return null;
        }
    }

}