/**
* 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.Arrays;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* ListStructObjectInspector 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.
*
* Always use the ObjectInspectorFactory to create new ObjectInspector objects,
* instead of directly creating an instance of this class.
*/
public class StandardStructObjectInspector extends
SettableStructObjectInspector {
public static final Logger LOG = LoggerFactory
.getLogger(StandardStructObjectInspector.class.getName());
protected static class MyField implements StructField {
protected int fieldID;
protected String fieldName;
protected ObjectInspector fieldObjectInspector;
protected String fieldComment;
protected MyField() {
super();
}
public MyField(int fieldID, String fieldName,
ObjectInspector fieldObjectInspector) {
this.fieldID = fieldID;
this.fieldName = fieldName.toLowerCase().intern();
this.fieldObjectInspector = fieldObjectInspector;
}
public MyField(int fieldID, String fieldName,
ObjectInspector fieldObjectInspector, String fieldComment) {
this(fieldID, fieldName, fieldObjectInspector);
this.fieldComment = fieldComment;
}
public int getFieldID() {
return fieldID;
}
public String getFieldName() {
return fieldName;
}
public ObjectInspector getFieldObjectInspector() {
return fieldObjectInspector;
}
public String getFieldComment() {
return fieldComment;
}
@Override
public String toString() {
return "" + fieldID + ":" + fieldName;
}
}
protected List<MyField> fields;
protected transient List<String> originalColumnNames;
protected StandardStructObjectInspector() {
super();
}
/**
* Call ObjectInspectorFactory.getStandardListObjectInspector instead.
*/
protected StandardStructObjectInspector(List<String> structFieldNames,
List<ObjectInspector> structFieldObjectInspectors) {
init(structFieldNames, structFieldObjectInspectors, null);
}
/**
* Call ObjectInspectorFactory.getStandardListObjectInspector instead.
*/
protected StandardStructObjectInspector(List<String> structFieldNames,
List<ObjectInspector> structFieldObjectInspectors,
List<String> structFieldComments) {
init(structFieldNames, structFieldObjectInspectors, structFieldComments);
}
protected void init(List<String> structFieldNames,
List<ObjectInspector> structFieldObjectInspectors,
List<String> structFieldComments) {
fields = new ArrayList<MyField>(structFieldNames.size());
originalColumnNames = new ArrayList<String>(structFieldNames.size());
for (int i = 0; i < structFieldNames.size(); i++) {
fields.add(new MyField(i, structFieldNames.get(i),
structFieldObjectInspectors.get(i),
structFieldComments == null ? null : structFieldComments.get(i)));
originalColumnNames.add(structFieldNames.get(i));
}
}
protected StandardStructObjectInspector(List<StructField> fields) {
init(fields);
}
protected void init(List<StructField> fields) {
this.fields = new ArrayList<MyField>(fields.size());
this.originalColumnNames = new ArrayList<String>(fields.size());
for (int i = 0; i < fields.size(); i++) {
this.fields.add(new MyField(i, fields.get(i).getFieldName(), fields
.get(i).getFieldObjectInspector()));
this.originalColumnNames.add(fields.get(i).getFieldName());
}
}
public String getTypeName() {
return ObjectInspectorUtils.getStandardStructTypeName(this);
}
public final Category getCategory() {
return Category.STRUCT;
}
// Without Data
@Override
public StructField getStructFieldRef(String fieldName) {
return ObjectInspectorUtils.getStandardStructFieldRef(fieldName, fields);
}
@Override
public List<? extends StructField> getAllStructFieldRefs() {
return fields;
}
boolean warned = false;
// With Data
@Override
@SuppressWarnings("unchecked")
public Object getStructFieldData(Object data, StructField fieldRef) {
if (data == null) {
return null;
}
// We support both List<Object> and Object[]
// so we have to do differently.
boolean isArray = data.getClass().isArray();
if (!isArray && !(data instanceof List)) {
if (!warned) {
LOG.warn("Invalid type for struct " + data.getClass());
LOG.warn("ignoring similar errors.");
warned = true;
}
return data;
}
int listSize = (isArray ? ((Object[]) data).length : ((List<Object>) data)
.size());
MyField f = (MyField) fieldRef;
if (fields.size() != listSize && !warned) {
// TODO: remove this
warned = true;
LOG.warn("Trying to access " + fields.size()
+ " fields inside a list of " + listSize + " elements: "
+ (isArray ? Arrays.asList((Object[]) data) : (List<Object>) data));
LOG.warn("ignoring similar errors.");
}
int fieldID = f.getFieldID();
if (fieldID >= listSize) {
return null;
} else if (isArray) {
return ((Object[]) data)[fieldID];
} else {
return ((List<Object>) data).get(fieldID);
}
}
@Override
@SuppressWarnings("unchecked")
public List<Object> getStructFieldsDataAsList(Object data) {
if (data == null) {
return null;
}
// We support both List<Object> and Object[]
// so we have to do differently.
if (! (data instanceof List)) {
data = java.util.Arrays.asList((Object[]) data);
}
List<Object> list = (List<Object>) data;
return list;
}
public List<String> getOriginalColumnNames() {
return originalColumnNames;
}
// /////////////////////////////
// SettableStructObjectInspector
@Override
public Object create() {
ArrayList<Object> a = new ArrayList<Object>(fields.size());
for (int i = 0; i < fields.size(); i++) {
a.add(null);
}
return a;
}
@Override
public Object setStructFieldData(Object struct, StructField field,
Object fieldValue) {
ArrayList<Object> a = (ArrayList<Object>) struct;
MyField myField = (MyField) field;
a.set(myField.fieldID, fieldValue);
return a;
}
}