org.apache.hadoop.hive.serde2.objectinspector.MetadataListStructObjectInspector Maven / Gradle / Ivy
/**
* 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.serde2.objectinspector;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.hadoop.hive.serde2.ColumnSet;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector.PrimitiveCategory;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
/**
* StructObjectInspector works on struct data that is stored as a Java List or
* Java Array object. Basically, the fields are stored sequentially in the List
* object.
*
* The names of the struct fields and the internal structure of the struct
* fields are specified in the ctor of the StructObjectInspector.
*
*/
public class MetadataListStructObjectInspector extends
StandardStructObjectInspector {
static ConcurrentHashMap>, MetadataListStructObjectInspector>
cached = new ConcurrentHashMap>, MetadataListStructObjectInspector>();
// public static MetadataListStructObjectInspector getInstance(int fields) {
// return getInstance(ObjectInspectorUtils.getIntegerArray(fields));
// }
public static MetadataListStructObjectInspector getInstance(
List columnNames) {
ArrayList> key = new ArrayList>(1);
key.add(columnNames);
MetadataListStructObjectInspector result = cached.get(key);
if (result == null) {
result = new MetadataListStructObjectInspector(columnNames);
MetadataListStructObjectInspector prev = cached.putIfAbsent(key, result);
if (prev != null) {
result = prev;
}
}
return result;
}
public static MetadataListStructObjectInspector getInstance(
List columnNames, List columnComments) {
ArrayList> key = new ArrayList>(2);
Collections.addAll(key, columnNames, columnComments);
MetadataListStructObjectInspector result = cached.get(key);
if (result == null) {
result = new MetadataListStructObjectInspector(columnNames, columnComments);
MetadataListStructObjectInspector prev = cached.putIfAbsent(key, result);
if (prev != null) {
result = prev;
}
}
return result;
}
static ArrayList getFieldObjectInspectors(int fields) {
ArrayList r = new ArrayList(fields);
for (int i = 0; i < fields; i++) {
r.add(PrimitiveObjectInspectorFactory
.getPrimitiveJavaObjectInspector(PrimitiveCategory.STRING));
}
return r;
}
protected MetadataListStructObjectInspector() {
super();
}
MetadataListStructObjectInspector(List columnNames) {
super(columnNames, getFieldObjectInspectors(columnNames.size()));
}
public MetadataListStructObjectInspector(List columnNames,
List columnComments) {
super(columnNames, getFieldObjectInspectors(columnNames.size()),
columnComments);
}
// Get col object out
@Override
public Object getStructFieldData(Object data, StructField fieldRef) {
if (data instanceof ColumnSet) {
data = ((ColumnSet) data).col;
}
return super.getStructFieldData(data, fieldRef);
}
// Get col object out
@Override
public List