com.lithium.yoda.UsWeekYear.java Source code

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Here is the source code for com.lithium.yoda.UsWeekYear.java

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/*
 * Licensed to Lithium Technologies Inc. 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 com.lithium.yoda;

import com.google.common.base.Preconditions;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.LongObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;

import java.util.Calendar;
import java.util.TimeZone;

/**
 * @author pradeep.gollakota
 */
public class UsWeekYear extends AbstractYodaUdf {
    private transient LongObjectInspector timestampOi;
    private transient Calendar calendar = Calendar.getInstance();

    @Override
    public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
        Preconditions.checkPositionIndex(0, arguments.length);
        if (!(arguments[0] instanceof LongObjectInspector)) {
            throw new IllegalArgumentException(
                    "Input to UsWeekOfWeekYear UDF must be a bigint. Given " + arguments[0].getTypeName());
        }
        timestampOi = (LongObjectInspector) arguments[0];

        calendar.setTimeZone(TimeZone.getTimeZone("UTC"));
        calendar.setFirstDayOfWeek(Calendar.SUNDAY);
        calendar.setMinimalDaysInFirstWeek(4); // Which ever year has 4 weeks starting on Sunday get's the week
        return PrimitiveObjectInspectorFactory.javaIntObjectInspector;
    }

    @Override
    public Object evaluate(DeferredObject[] arguments) throws HiveException {
        calendar.setTimeInMillis(timestampOi.get(arguments[0].get()));
        return calendar.getWeekYear();
    }
}