org.apache.hadoop.hive.ql.udf.generic.GenericUDFToDate Maven / Gradle / Ivy
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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 org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
import org.apache.hadoop.hive.ql.exec.vector.VectorizedExpressions;
import org.apache.hadoop.hive.ql.exec.vector.expressions.CastLongToDate;
import org.apache.hadoop.hive.ql.exec.vector.expressions.CastStringToDate;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector.PrimitiveCategory;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorConverter.DateConverter;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils.PrimitiveGrouping;
/**
* GenericUDFToDate
*/
@Description(name = "date",
value = "CAST( as DATE) - Returns the date represented by the date string.",
extended = "date_string is a string in the format 'yyyy-MM-dd.'"
+ "Example:\n "
+ " > SELECT CAST('2009-01-01' AS DATE) FROM src LIMIT 1;\n"
+ " '2009-01-01'")
@VectorizedExpressions({CastStringToDate.class, CastLongToDate.class})
public class GenericUDFToDate extends GenericUDF {
private transient PrimitiveObjectInspector argumentOI;
private transient DateConverter dc;
@Override
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
if (arguments.length < 1) {
throw new UDFArgumentLengthException(
"The function CAST as DATE requires at least one argument, got "
+ arguments.length);
}
try {
argumentOI = (PrimitiveObjectInspector) arguments[0];
PrimitiveCategory pc = argumentOI.getPrimitiveCategory();
PrimitiveGrouping pg =
PrimitiveObjectInspectorUtils.getPrimitiveGrouping(pc);
switch (pg) {
case DATE_GROUP:
case STRING_GROUP:
case VOID_GROUP:
break;
default:
throw new UDFArgumentException(
"CAST as DATE only allows date,string, or timestamp types");
}
} catch (ClassCastException e) {
throw new UDFArgumentException(
"The function CAST as DATE takes only primitive types");
}
dc = new DateConverter(argumentOI,
PrimitiveObjectInspectorFactory.writableDateObjectInspector);
return PrimitiveObjectInspectorFactory.writableDateObjectInspector;
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
Object o0 = arguments[0].get();
if (o0 == null) {
return null;
}
return dc.convert(o0);
}
@Override
public String getDisplayString(String[] children) {
assert (children.length == 1);
StringBuilder sb = new StringBuilder();
sb.append("CAST( ");
sb.append(children[0]);
sb.append(" AS DATE)");
return sb.toString();
}
}