/**
* 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.contrib.udtf.example;
import java.util.ArrayList;
import java.util.List;
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.ql.udf.generic.GenericUDTF;
import org.apache.hadoop.hive.serde2.objectinspector.ListObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector;
/**
* GenericUDTFExplode2.
*
*/
@Description(name = "explode2",
value = "_FUNC_(a) - like explode, but outputs two identical columns (for testing purposes)")
public class GenericUDTFExplode2 extends GenericUDTF {
private transient ListObjectInspector listOI = null;
@Override
public void close() throws HiveException {
}
@Override
public StructObjectInspector initialize(ObjectInspector[] args)
throws UDFArgumentException {
if (args.length != 1) {
throw new UDFArgumentException("explode() takes only one argument");
}
if (args[0].getCategory() != ObjectInspector.Category.LIST) {
throw new UDFArgumentException("explode() takes an array as a parameter");
}
listOI = (ListObjectInspector) args[0];
ArrayList<String> fieldNames = new ArrayList<String>();
ArrayList<ObjectInspector> fieldOIs = new ArrayList<ObjectInspector>();
fieldNames.add("col1");
fieldNames.add("col2");
fieldOIs.add(listOI.getListElementObjectInspector());
fieldOIs.add(listOI.getListElementObjectInspector());
return ObjectInspectorFactory.getStandardStructObjectInspector(fieldNames,
fieldOIs);
}
Object forwardObj[] = new Object[2];
@Override
public void process(Object[] o) throws HiveException {
List<?> list = listOI.getList(o[0]);
for (Object r : list) {
forwardObj[0] = r;
forwardObj[1] = r;
forward(forwardObj);
}
}
@Override
public String toString() {
return "explode";
}
}