/*
* Copyright © 2014 Cask Data, Inc.
*
* Licensed 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 co.cask.cdap.hive.objectinspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorUtils;
import org.apache.hadoop.hive.serde2.objectinspector.UnionObject;
import org.apache.hadoop.hive.serde2.objectinspector.UnionObjectInspector;
import java.util.List;
/**
* StandardUnionObjectInspector works on union data that is stored as
* UnionObject.
* It holds the list of the object inspectors corresponding to each type of the
* object the Union can hold. The UniobObject has tag followed by the object
* it is holding.
*
* Always use the {@link org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory}
* to create new ObjectInspector objects, instead of directly creating an instance of this class.
*/
public class StandardUnionObjectInspector implements UnionObjectInspector {
List<ObjectInspector> ois;
public StandardUnionObjectInspector(List<ObjectInspector> ois) {
this.ois = ois;
}
public List<ObjectInspector> getObjectInspectors() {
return ois;
}
/**
* Standard Union.
*/
public static class StandardUnion implements UnionObject {
protected byte tag;
protected Object object;
public StandardUnion() {
}
public StandardUnion(byte tag, Object object) {
this.tag = tag;
this.object = object;
}
public void setObject(Object o) {
this.object = o;
}
public void setTag(byte tag) {
this.tag = tag;
}
@Override
public Object getObject() {
return object;
}
@Override
public byte getTag() {
return tag;
}
@Override
public String toString() {
return tag + ":" + object;
}
}
/**
* Return the tag of the object.
*/
public byte getTag(Object o) {
if (o == null) {
return -1;
}
return ((UnionObject) o).getTag();
}
/**
* Return the field based on the tag value associated with the Object.
*/
public Object getField(Object o) {
if (o == null) {
return null;
}
return ((UnionObject) o).getObject();
}
public Category getCategory() {
return Category.UNION;
}
public String getTypeName() {
return ObjectInspectorUtils.getStandardUnionTypeName(this);
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append(getClass().getName());
sb.append(getTypeName());
return sb.toString();
}
}