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* 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.generic;
import static org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils.PrimitiveGrouping.DATE_GROUP;
import static org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils.PrimitiveGrouping.NUMERIC_GROUP;
import static org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils.PrimitiveGrouping.STRING_GROUP;
import static org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils.PrimitiveGrouping.VOID_GROUP;
import java.util.Calendar;
import java.util.Date;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde2.objectinspector.ConstantObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters.Converter;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector.PrimitiveCategory;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.io.Text;
import org.apache.hive.common.util.DateUtils;
/**
* GenericUDFAddMonths.
*
* Add a number of months to the date. The time part of the string will be
* ignored.
*
*/
@Description(name = "add_months",
value = "_FUNC_(start_date, num_months) - Returns the date that is num_months after start_date.",
extended = "start_date is a string in the format 'yyyy-MM-dd HH:mm:ss' or"
+ " 'yyyy-MM-dd'. num_months is a number. The time part of start_date is "
+ "ignored.\n"
+ "Example:\n " + " > SELECT _FUNC_('2009-08-31', 1) FROM src LIMIT 1;\n" + " '2009-09-30'")
public class GenericUDFAddMonths extends GenericUDF {
private transient Converter[] converters = new Converter[2];
private transient PrimitiveCategory[] inputTypes = new PrimitiveCategory[2];
private final Calendar calendar = Calendar.getInstance();
private final Text output = new Text();
private transient Integer numMonthsConst;
private transient boolean isNumMonthsConst;
@Override
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
checkArgsSize(arguments, 2, 2);
checkArgPrimitive(arguments, 0);
checkArgPrimitive(arguments, 1);
checkArgGroups(arguments, 0, inputTypes, STRING_GROUP, DATE_GROUP, VOID_GROUP);
checkArgGroups(arguments, 1, inputTypes, NUMERIC_GROUP, VOID_GROUP);
obtainDateConverter(arguments, 0, inputTypes, converters);
obtainIntConverter(arguments, 1, inputTypes, converters);
if (arguments[1] instanceof ConstantObjectInspector) {
numMonthsConst = getConstantIntValue(arguments, 1);
isNumMonthsConst = true;
}
ObjectInspector outputOI = PrimitiveObjectInspectorFactory.writableStringObjectInspector;
return outputOI;
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
Integer numMonthV;
if (isNumMonthsConst) {
numMonthV = numMonthsConst;
} else {
numMonthV = getIntValue(arguments, 1, converters);
}
if (numMonthV == null) {
return null;
}
int numMonthInt = numMonthV.intValue();
Date date = getDateValue(arguments, 0, inputTypes, converters);
if (date == null) {
return null;
}
addMonth(date, numMonthInt);
Date newDate = calendar.getTime();
output.set(DateUtils.getDateFormat().format(newDate));
return output;
}
@Override
public String getDisplayString(String[] children) {
return getStandardDisplayString(getFuncName(), children);
}
@Override
protected String getFuncName() {
return "add_months";
}
protected Calendar addMonth(Date d, int numMonths) {
calendar.setTime(d);
boolean lastDatOfMonth = isLastDayOfMonth(calendar);
calendar.add(Calendar.MONTH, numMonths);
if (lastDatOfMonth) {
int maxDd = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
calendar.set(Calendar.DAY_OF_MONTH, maxDd);
}
return calendar;
}
protected boolean isLastDayOfMonth(Calendar cal) {
int maxDd = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
int dd = cal.get(Calendar.DAY_OF_MONTH);
return dd == maxDd;
}
}