/**
* 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 java.util.ArrayList;
import java.util.Collections;
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.UDFArgumentTypeException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde.Constants;
import org.apache.hadoop.hive.serde2.objectinspector.ListObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector.Category;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters.Converter;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.StringObjectInspector;
/**
* Generic UDF for array sort
* <code>SORT_ARRAY(array(obj1, obj2, obj3...))</code>.
*
* @see org.apache.hadoop.hive.ql.udf.generic.GenericUDF
*/
@Description(name = "sort_array",
value = "_FUNC_(array(obj1, obj2,...)) - "
+ "Sorts the input array in ascending order according to the natural ordering"
+ " of the array elements.",
extended = "Example:\n"
+ " > SELECT _FUNC_(array('b', 'd', 'c', 'a')) FROM src LIMIT 1;\n"
+ " 'a', 'b', 'c', 'd'")
public class GenericUDFSortArray extends GenericUDF {
private Converter[] converters;
private ArrayList<Object> ret = new ArrayList<Object>();
private ObjectInspector[] argumentOIs;
@Override
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
GenericUDFUtils.ReturnObjectInspectorResolver returnOIResolver;
returnOIResolver = new GenericUDFUtils.ReturnObjectInspectorResolver(true);
if (arguments.length != 1) {
throw new UDFArgumentLengthException(
"The function SORT_ARRAY(array(obj1, obj2,...)) needs one argument.");
}
switch(arguments[0].getCategory()) {
case LIST:
if(((ListObjectInspector)(arguments[0])).getListElementObjectInspector()
.getCategory().equals(Category.PRIMITIVE))
break;
default:
throw new UDFArgumentTypeException(0, "Argument 1"
+ " of function SORT_ARRAY must be " + Constants.LIST_TYPE_NAME
+ "<" + Category.PRIMITIVE + ">, but " + arguments[0].getTypeName()
+ " was found.");
}
ObjectInspector elementObjectInspector =
((ListObjectInspector)(arguments[0])).getListElementObjectInspector();
argumentOIs = arguments;
converters = new Converter[arguments.length];
ObjectInspector returnOI = returnOIResolver.get();
if (returnOI == null) {
returnOI = elementObjectInspector;
}
converters[0] = ObjectInspectorConverters.getConverter(elementObjectInspector, returnOI);
return ObjectInspectorFactory.getStandardListObjectInspector(returnOI);
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
if (arguments[0].get() == null) {
return null;
}
Object array = arguments[0].get();
ListObjectInspector arrayOI = (ListObjectInspector) argumentOIs[0];
ArrayList retArray = (ArrayList) arrayOI.getList(array);
Collections.sort(retArray);
ret.clear();
for (int i = 0; i < retArray.size(); i++) {
ret.add(converters[0].convert(retArray.get(i)));
}
return ret;
}
@Override
public String getDisplayString(String[] children) {
assert (children.length == 1);
return "sort_array(" + children[0] + ")";
}
}