/**
* 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.UDFArgumentException;
import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
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.primitive.PrimitiveObjectInspectorConverter.TimestampConverter;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
/**
*
* GenericUDFTimestamp
*
* Example usage:
* ... CAST(<Timestamp string> as TIMESTAMP) ...
*
* Creates a TimestampWritable object using PrimitiveObjectInspectorConverter
*
*/
public class GenericUDFTimestamp extends GenericUDF {
private PrimitiveObjectInspector argumentOI;
private TimestampConverter tc;
@Override
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
if (arguments.length < 1) {
throw new UDFArgumentLengthException(
"The function TIMESTAMP requires at least one argument, got "
+ arguments.length);
}
try {
argumentOI = (PrimitiveObjectInspector) arguments[0];
} catch (ClassCastException e) {
throw new UDFArgumentException(
"The function TIMESTAMP takes only primitive types");
}
tc = new TimestampConverter(argumentOI,
PrimitiveObjectInspectorFactory.writableTimestampObjectInspector);
return PrimitiveObjectInspectorFactory.writableTimestampObjectInspector;
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
Object o0 = arguments[0].get();
if (o0 == null) {
return null;
}
return tc.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 TIMESTAMP)");
return sb.toString();
}
}