org.apache.hadoop.hive.serde2.objectinspector.SubStructObjectInspector 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.List;
/**
* SubsetStructObjectInspector implement a wrapper around a base object inspector (baseOI)
* such that when the row corresponding to the baseOI is given together with this object
* inspector, it will mask out some fields in the row as if they are not there.
*/
public class SubStructObjectInspector extends StructObjectInspector {
protected StructObjectInspector baseOI; // base object inspector
protected int startCol; // start column number
protected int numCols; // number of columns
protected List fields;
/**
* Create a new Object Inspector based on a base object inspector and the subset of
* columns will be inspected (from startCol to startCol+numCols).
* @param baseOI
* @param startCol
* @param numCols
*/
public SubStructObjectInspector(StructObjectInspector baseOI, int startCol, int numCols) {
this.baseOI = baseOI;
this.startCol = startCol;
this.numCols = numCols;
List baseFields = baseOI.getAllStructFieldRefs();
assert startCol < baseFields.size() && startCol + numCols < baseFields.size();
this.fields = new ArrayList(numCols);
this.fields.addAll(baseOI.getAllStructFieldRefs().subList(startCol, startCol + numCols));
}
@Override
public String getTypeName() {
return ObjectInspectorUtils.getStandardStructTypeName(this);
}
@Override
public Category getCategory() {
return Category.STRUCT;
}
@Override
public List getAllStructFieldRefs() {
return this.fields;
}
@Override
public StructField getStructFieldRef(String fieldName) {
return ObjectInspectorUtils.getStandardStructFieldRef(fieldName, fields);
}
@Override
public Object getStructFieldData(Object data, StructField fieldRef) {
return baseOI.getStructFieldData(data, fieldRef);
}
@Override
public List