org.apache.hadoop.hive.serde2.objectinspector.StructField Java Examples

public void testSimpleXmlLong() throws SerDeException {
    XmlSerDe xmlSerDe = new XmlSerDe();
    Configuration configuration = new Configuration();
    Properties properties = new Properties();
    properties.put(LIST_COLUMNS, "test");
    properties.put(LIST_COLUMN_TYPES, "bigint");
    properties.setProperty("column.xpath.test", "/test/text()");
    xmlSerDe.initialize(configuration, properties);
    Text text = new Text();
    text.set("<test>123456</test>");
    Object o = xmlSerDe.deserialize(text);
    XmlStructObjectInspector structInspector = ((XmlStructObjectInspector) xmlSerDe.getObjectInspector());
    StructField structField = structInspector.getStructFieldRef("test");
    Object data = structInspector.getStructFieldData(o, structField);
    assertEquals(123456l, data);
}
 

private static void checkResultInspector(ObjectInspector resultInspector) {
  Assert.assertNotNull(resultInspector);
  Assert.assertEquals(resultInspector.getCategory(), ObjectInspector.Category.STRUCT);
  List<? extends StructField> fields = ((StructObjectInspector) resultInspector).getAllStructFieldRefs();
  Assert.assertEquals(fields.size(), 4);
  Assert.assertEquals(fields.get(0).getFieldObjectInspector().getCategory(), ObjectInspector.Category.PRIMITIVE);
  Assert.assertEquals(
    ((PrimitiveObjectInspector) fields.get(0).getFieldObjectInspector()).getPrimitiveCategory(),
    PrimitiveObjectInspector.PrimitiveCategory.STRING
  );
  Assert.assertEquals(fields.get(1).getFieldObjectInspector().getCategory(), ObjectInspector.Category.PRIMITIVE);
  Assert.assertEquals(
    ((PrimitiveObjectInspector) fields.get(1).getFieldObjectInspector()).getPrimitiveCategory(),
    PrimitiveObjectInspector.PrimitiveCategory.LONG
  );
  Assert.assertEquals(fields.get(2).getFieldObjectInspector().getCategory(), ObjectInspector.Category.PRIMITIVE);
  Assert.assertEquals(
    ((PrimitiveObjectInspector) fields.get(2).getFieldObjectInspector()).getPrimitiveCategory(),
    PrimitiveObjectInspector.PrimitiveCategory.LONG
  );
  Assert.assertEquals(fields.get(3).getFieldObjectInspector().getCategory(), ObjectInspector.Category.PRIMITIVE);
  Assert.assertEquals(
    ((PrimitiveObjectInspector) fields.get(3).getFieldObjectInspector()).getPrimitiveCategory(),
    PrimitiveObjectInspector.PrimitiveCategory.LONG
  );
}
 

@SuppressWarnings("rawtypes")
public void testSimpleXmlNotMap() throws SerDeException {
    XmlSerDe xmlSerDe = new XmlSerDe();
    Configuration configuration = new Configuration();
    Properties properties = new Properties();
    properties.put(LIST_COLUMNS, "test");
    properties.put(LIST_COLUMN_TYPES, "map<string,string>");
    properties.setProperty("column.xpath.test", "//*[contains(name(),'test')]/text()");
    xmlSerDe.initialize(configuration, properties);
    Text text = new Text();
    text.set("<root><test1>string1</test1><test2>string2</test2></root>");
    Object o = xmlSerDe.deserialize(text);
    XmlStructObjectInspector structInspector = ((XmlStructObjectInspector) xmlSerDe.getObjectInspector());
    StructField structField = structInspector.getStructFieldRef("test");
    Object data = structInspector.getStructFieldData(o, structField);
    XmlMapObjectInspector fieldInspector = (XmlMapObjectInspector) structField.getFieldObjectInspector();
    Map map = fieldInspector.getMap(data);
    assertEquals(0, map.size());
}
 

public void testSimpleXmlFloat() throws SerDeException {
    XmlSerDe xmlSerDe = new XmlSerDe();
    Configuration configuration = new Configuration();
    Properties properties = new Properties();
    properties.put(LIST_COLUMNS, "test");
    properties.put(LIST_COLUMN_TYPES, "float");
    properties.setProperty("column.xpath.test", "/test/text()");
    xmlSerDe.initialize(configuration, properties);
    Text text = new Text();
    text.set("<test>123.456</test>");
    Object o = xmlSerDe.deserialize(text);
    XmlStructObjectInspector structInspector = ((XmlStructObjectInspector) xmlSerDe.getObjectInspector());
    StructField structField = structInspector.getStructFieldRef("test");
    Object data = structInspector.getStructFieldData(o, structField);
    assertEquals(123.456f, data);
}
 

@Override
public boolean equals(Object o) {
  if (o == null || o.getClass() != getClass()) {
    return false;
  } else if (o == this) {
    return true;
  } else {
    List<StructField> other = ((OrcLazyStructObjectInspector) o).fields;
    if (other.size() != fields.size()) {
      return false;
    }
    for(int i = 0; i < fields.size(); ++i) {
      StructField left = other.get(i);
      StructField right = fields.get(i);
      if (!(left.getFieldName().equals(right.getFieldName()) &&
            left.getFieldObjectInspector().equals
                (right.getFieldObjectInspector()))) {
        return false;
      }
    }
    return true;
  }
}
 

/**
 * Deparses struct data into a serializable JSON object.
 *
 * @param obj      - Hive struct data
 * @param structOI - ObjectInspector for the struct
 * @param isRow    - Whether or not this struct represents a top-level row
 * @return - A deparsed struct
 */
private Object deparseStruct(Object obj,
							 StructObjectInspector structOI,
							 boolean isRow) {
	Map<Object, Object> struct = new HashMap<Object, Object>();
	List<? extends StructField> fields = structOI.getAllStructFieldRefs();
	for (int i = 0; i < fields.size(); i++) {
		StructField field = fields.get(i);
		// The top-level row object is treated slightly differently from other
		// structs, because the field names for the row do not correctly reflect
		// the Hive column names. For lower-level structs, we can get the field
		// name from the associated StructField object.
		String fieldName = isRow ? colNames.get(i) : field.getFieldName();
		ObjectInspector fieldOI = field.getFieldObjectInspector();
		Object fieldObj = structOI.getStructFieldData(obj, field);
		struct.put(fieldName, deparseObject(fieldObj, fieldOI));
	}
	return struct;
}
 

public void testSimpleXmlByte() throws SerDeException {
    XmlSerDe xmlSerDe = new XmlSerDe();
    Configuration configuration = new Configuration();
    Properties properties = new Properties();
    properties.put(LIST_COLUMNS, "test");
    properties.put(LIST_COLUMN_TYPES, "tinyint");
    properties.setProperty("column.xpath.test", "/test/text()");
    xmlSerDe.initialize(configuration, properties);
    Text text = new Text();
    text.set("<test>14</test>");
    Object o = xmlSerDe.deserialize(text);
    XmlStructObjectInspector structInspector = ((XmlStructObjectInspector) xmlSerDe.getObjectInspector());
    StructField structField = structInspector.getStructFieldRef("test");
    Object data = structInspector.getStructFieldData(o, structField);
    assertEquals((byte) 14, ((Byte) data).byteValue());
}
 

private static void createSequentialFile(File file, int count)
        throws IOException, SerDeException
{
    FileSinkOperator.RecordWriter writer = createOrcRecordWriter(file, ORC_12, CompressionKind.NONE, BIGINT);

    Serializer serde = new OrcSerde();
    SettableStructObjectInspector objectInspector = createSettableStructObjectInspector("test", BIGINT);
    Object row = objectInspector.create();
    StructField field = objectInspector.getAllStructFieldRefs().get(0);

    for (int i = 0; i < count; i++) {
        objectInspector.setStructFieldData(row, field, (long) i);
        Writable record = serde.serialize(row, objectInspector);
        writer.write(record);
    }

    writer.close(false);
}
 

public static DataSize writeOrcFileColumnHive(File outputFile, RecordWriter recordWriter, Type type, Iterator<?> values)
        throws Exception
{
    SettableStructObjectInspector objectInspector = createSettableStructObjectInspector("test", type);
    Object row = objectInspector.create();

    List<StructField> fields = ImmutableList.copyOf(objectInspector.getAllStructFieldRefs());
    Serializer serializer = new OrcSerde();

    while (values.hasNext()) {
        Object value = values.next();
        value = preprocessWriteValueHive(type, value);
        objectInspector.setStructFieldData(row, fields.get(0), value);

        Writable record = serializer.serialize(row, objectInspector);
        recordWriter.write(record);
    }

    recordWriter.close(false);
    return succinctBytes(outputFile.length());
}
 

@Override
public String getTypeName() {
  StringBuilder buffer = new StringBuilder();
  buffer.append("struct<");
  for(int i=0; i < fields.size(); ++i) {
    StructField field = fields.get(i);
    if (i != 0) {
      buffer.append(",");
    }
    buffer.append(field.getFieldName());
    buffer.append(":");
    buffer.append(field.getFieldObjectInspector().getTypeName());
  }
  buffer.append(">");
  return buffer.toString();
}
 

@Test
public void TestIntParse() throws Exception {
	Configuration config = new Configuration();
	Text value = new Text();

	AbstractSerDe jserde = new EsriJsonSerDe();
	Properties proptab = new Properties();
	proptab.setProperty(HiveShims.serdeConstants.LIST_COLUMNS, "num");
	proptab.setProperty(HiveShims.serdeConstants.LIST_COLUMN_TYPES, "int");
	jserde.initialize(config, proptab);
       StructObjectInspector rowOI = (StructObjectInspector)jserde.getObjectInspector();

       //value.set("{\"attributes\":{\"num\":7},\"geometry\":null}");
       value.set("{\"attributes\":{\"num\":7}}");
	Object row = jserde.deserialize(value);
	StructField f0 = rowOI.getStructFieldRef("num");
	Object fieldData = rowOI.getStructFieldData(row, f0);
	Assert.assertEquals(7, ((IntWritable)fieldData).get());
       value.set("{\"attributes\":{\"num\":9}}");
       row = jserde.deserialize(value);
	f0 = rowOI.getStructFieldRef("num");
	fieldData = rowOI.getStructFieldData(row, f0);
	Assert.assertEquals(9, ((IntWritable)fieldData).get());
}
 

/**
 * Write a file that contains a number of rows with 1 VARCHAR column, and all values are not null.
 */
private static TempFile createSingleColumnVarcharFile(int count, int length)
        throws Exception
{
    Serializer serde = new OrcSerde();
    TempFile tempFile = new TempFile();
    FileSinkOperator.RecordWriter writer = createOrcRecordWriter(tempFile.getFile(), ORC_12, CompressionKind.NONE, VARCHAR);
    SettableStructObjectInspector objectInspector = createSettableStructObjectInspector("test", VARCHAR);
    Object row = objectInspector.create();
    StructField field = objectInspector.getAllStructFieldRefs().get(0);

    for (int i = 0; i < count; i++) {
        objectInspector.setStructFieldData(row, field, Strings.repeat("0", length));
        Writable record = serde.serialize(row, objectInspector);
        writer.write(record);
    }

    writer.close(false);
    return tempFile;
}
 

/**
 * @see org.apache.hadoop.hive.serde2.objectinspector.StandardStructObjectInspector#getStructFieldData(java.lang.Object,
 *      org.apache.hadoop.hive.serde2.objectinspector.StructField)
 */
@SuppressWarnings("unchecked")
@Override
public Object getStructFieldData(Object data, StructField structField) {
    if ((data instanceof List) && !(data instanceof SerDeArray)) {
        MyField f = (MyField) structField;
        int fieldID = f.getFieldID();
        return ((List<Object>) data).get(fieldID);
    } else {
        ObjectInspector fieldObjectInspector = structField.getFieldObjectInspector();
        Category category = fieldObjectInspector.getCategory();
        Object fieldData = this.xmlProcessor.getObjectValue(data, structField.getFieldName());
        switch (category) {
            case PRIMITIVE: {
                PrimitiveObjectInspector primitiveObjectInspector = (PrimitiveObjectInspector) fieldObjectInspector;
                PrimitiveCategory primitiveCategory = primitiveObjectInspector.getPrimitiveCategory();
                return this.xmlProcessor.getPrimitiveObjectValue(fieldData, primitiveCategory);
            }
            default:
                return fieldData;
        }
    }
}
 

@Test
public void TestIntParse() throws Exception {
	Configuration config = new Configuration();
	Text value = new Text();

	AbstractSerDe jserde = new GeoJsonSerDe();
	Properties proptab = new Properties();
	proptab.setProperty(HiveShims.serdeConstants.LIST_COLUMNS, "num");
	proptab.setProperty(HiveShims.serdeConstants.LIST_COLUMN_TYPES, "int");
	jserde.initialize(config, proptab);
       StructObjectInspector rowOI = (StructObjectInspector)jserde.getObjectInspector();

       value.set("{\"properties\":{\"num\":7}}");
	Object row = jserde.deserialize(value);
	StructField f0 = rowOI.getStructFieldRef("num");
	Object fieldData = rowOI.getStructFieldData(row, f0);
	Assert.assertEquals(7, ((IntWritable)fieldData).get());
       value.set("{\"properties\":{\"num\":9}}");
       row = jserde.deserialize(value);
	f0 = rowOI.getStructFieldRef("num");
	fieldData = rowOI.getStructFieldData(row, f0);
	Assert.assertEquals(9, ((IntWritable)fieldData).get());
}
 

@Override
public Row nextRecord(Row ignore) throws IOException {
	if (reachedEnd()) {
		return null;
	}
	Row row = new Row(rowArity);
	try {
		//Use HiveDeserializer to deserialize an object out of a Writable blob
		Object hiveRowStruct = deserializer.deserialize(value);
		int index = 0;
		for (; index < structFields.size(); index++) {
			StructField structField = structFields.get(index);
			Object object = HiveInspectors.toFlinkObject(structField.getFieldObjectInspector(),
					structObjectInspector.getStructFieldData(hiveRowStruct, structField));
			row.setField(index, object);
		}
		for (String partition : partitionColNames){
			row.setField(index++, hiveTablePartition.getPartitionSpec().get(partition));
		}
	} catch (Exception e){
		logger.error("Error happens when converting hive data type to flink data type.");
		throw new FlinkHiveException(e);
	}
	this.fetched = false;
	return row;
}
 

public void testSimpleXmlInt() throws SerDeException {
    XmlSerDe xmlSerDe = new XmlSerDe();
    Configuration configuration = new Configuration();
    Properties properties = new Properties();
    properties.put(LIST_COLUMNS, "test");
    properties.put(LIST_COLUMN_TYPES, "int");
    properties.setProperty("column.xpath.test", "/test/text()");
    xmlSerDe.initialize(configuration, properties);
    Text text = new Text();
    text.set("<test>23</test>");
    Object o = xmlSerDe.deserialize(text);
    XmlStructObjectInspector structInspector = ((XmlStructObjectInspector) xmlSerDe.getObjectInspector());
    StructField structField = structInspector.getStructFieldRef("test");
    Object data = structInspector.getStructFieldData(o, structField);
    assertEquals(23, data);
}
 

@Override
public String getTypeName() {
  StringBuilder buffer = new StringBuilder();
  buffer.append("struct<");
  for(int i=0; i < fields.size(); ++i) {
    StructField field = fields.get(i);
    if (i != 0) {
      buffer.append(",");
    }
    buffer.append(field.getFieldName());
    buffer.append(":");
    buffer.append(field.getFieldObjectInspector().getTypeName());
  }
  buffer.append(">");
  return buffer.toString();
}
 

@Test
public void TestEpochParse() throws Exception {
	Configuration config = new Configuration();
	Text value = new Text();

	AbstractSerDe jserde = new EsriJsonSerDe();
	Properties proptab = new Properties();
	proptab.setProperty(HiveShims.serdeConstants.LIST_COLUMNS, "when");
	proptab.setProperty(HiveShims.serdeConstants.LIST_COLUMN_TYPES, "date");
	jserde.initialize(config, proptab);
       StructObjectInspector rowOI = (StructObjectInspector)jserde.getObjectInspector();

       value.set("{\"attributes\":{\"when\":147147147147}}");
	Object row = jserde.deserialize(value);
	StructField f0 = rowOI.getStructFieldRef("when");
	Object fieldData = rowOI.getStructFieldData(row, f0);
	//Assert.assertEquals(147147147147L, ((DateWritable)fieldData).get().getTime());
	Assert.assertEquals(new java.sql.Date(147147147147L).toString(),
						((DateWritable)fieldData).get().toString());
       value.set("{\"attributes\":{\"when\":142857142857}}");
       row = jserde.deserialize(value);
	fieldData = rowOI.getStructFieldData(row, f0);
	//Assert.assertEquals(142857142857L, ((DateWritable)fieldData).get());
	Assert.assertEquals(new java.sql.Date(142857142857L).toString(),
						((DateWritable)fieldData).get().toString());
}
 

@Override
public boolean equals(Object o) {
  if (o == null || o.getClass() != getClass()) {
    return false;
  } else if (o == this) {
    return true;
  } else {
    List<StructField> other = ((OrcStructInspector) o).fields;
    if (other.size() != fields.size()) {
      return false;
    }
    for(int i = 0; i < fields.size(); ++i) {
      StructField left = other.get(i);
      StructField right = fields.get(i);
      if (!(left.getFieldName().equals(right.getFieldName()) &&
            left.getFieldObjectInspector().equals
                (right.getFieldObjectInspector()))) {
        return false;
      }
    }
    return true;
  }
}
 

static void checkIntermediateResultInspector(ObjectInspector resultInspector) {
  Assert.assertNotNull(resultInspector);
  Assert.assertEquals(resultInspector.getCategory(), ObjectInspector.Category.STRUCT);
  StructObjectInspector structResultInspector = (StructObjectInspector) resultInspector;
  List<?> fields = structResultInspector.getAllStructFieldRefs();
  Assert.assertEquals(fields.size(), 3);

  ObjectInspector inspector1 = ((StructField) fields.get(0)).getFieldObjectInspector();
  Assert.assertEquals(inspector1.getCategory(), ObjectInspector.Category.PRIMITIVE);
  PrimitiveObjectInspector primitiveInspector1 = (PrimitiveObjectInspector) inspector1;
  Assert.assertEquals(primitiveInspector1.getPrimitiveCategory(), PrimitiveCategory.INT);

  ObjectInspector inspector2 = ((StructField) fields.get(1)).getFieldObjectInspector();
  Assert.assertEquals(inspector2.getCategory(), ObjectInspector.Category.PRIMITIVE);
  PrimitiveObjectInspector primitiveInspector2 = (PrimitiveObjectInspector) inspector2;
  Assert.assertEquals(primitiveInspector2.getPrimitiveCategory(), PrimitiveCategory.STRING);

  ObjectInspector inspector3 = ((StructField) fields.get(2)).getFieldObjectInspector();
  Assert.assertEquals(inspector3.getCategory(), ObjectInspector.Category.PRIMITIVE);
  PrimitiveObjectInspector primitiveInspector3 = (PrimitiveObjectInspector) inspector3;
  Assert.assertEquals(primitiveInspector3.getPrimitiveCategory(), PrimitiveCategory.BINARY);
}
 

/**
 * Helper method that creates {@link VectorizedRowBatch}. For each selected column an input vector is created in the
 * batch. For unselected columns the vector entry is going to be null. The order of input vectors in batch should
 * match the order the columns in ORC file.
 *
 * @param rowOI Used to find the ordinal of the selected column.
 * @return
 */
private VectorizedRowBatch createVectorizedRowBatch(StructObjectInspector rowOI, boolean isOriginal) {
  final List<? extends StructField> fieldRefs = rowOI.getAllStructFieldRefs();
  final List<ColumnVector> vectors = getVectors(rowOI);

  final VectorizedRowBatch result = new VectorizedRowBatch(fieldRefs.size());

  ColumnVector[] vectorArray =  vectors.toArray(new ColumnVector[0]);

  if (!isOriginal) {
    vectorArray = createTransactionalVectors(vectorArray);
  }

  result.cols = vectorArray;
  result.numCols = fieldRefs.size();
  result.reset();
  return result;
}
 

@Override
@SuppressWarnings("unchecked")
public RowData nextRecord(RowData reuse) throws IOException {
	if (reachedEnd()) {
		return null;
	}
	try {
		//Use HiveDeserializer to deserialize an object out of a Writable blob
		Object hiveRowStruct = deserializer.deserialize(value);
		for (int i = 0; i < selectedFields.length; i++) {
			// set non-partition columns
			if (selectedFields[i] < structFields.size()) {
				StructField structField = structFields.get(selectedFields[i]);
				Object object = HiveInspectors.toFlinkObject(structField.getFieldObjectInspector(),
						structObjectInspector.getStructFieldData(hiveRowStruct, structField), hiveShim);
				row.setField(i, converters[i].toInternal(object));
			}
		}
	} catch (Exception e) {
		LOG.error("Error happens when converting hive data type to flink data type.");
		throw new FlinkHiveException(e);
	}
	this.fetched = false;
	return row;
}
 

@Override
public Object getStructFieldData(final Object data, final StructField fieldRef) {
  if (data == null) {
    return null;
  }

  if (data instanceof ArrayWritable) {
    final ArrayWritable arr = (ArrayWritable) data;
    return arr.get()[((StructFieldImpl) fieldRef).getIndex()];
  }

  //since setStructFieldData and create return a list, getStructFieldData should be able to 
  //handle list data. This is required when table serde is ParquetHiveSerDe and partition serde
  //is something else.
  if (data instanceof List) {
    return ((List) data).get(((StructFieldImpl) fieldRef).getIndex());
  }

  throw new UnsupportedOperationException("Cannot inspect " + data.getClass().getCanonicalName());
}
 

private static void checkIntermediateResultInspector(ObjectInspector resultInspector) {
  Assert.assertNotNull(resultInspector);
  Assert.assertEquals(resultInspector.getCategory(), ObjectInspector.Category.STRUCT);
  StructObjectInspector structResultInspector = (StructObjectInspector) resultInspector;
  List<?> fields = structResultInspector.getAllStructFieldRefs();
  Assert.assertEquals(fields.size(), 2);

  ObjectInspector inspector1 = ((StructField) fields.get(0)).getFieldObjectInspector();
  Assert.assertEquals(inspector1.getCategory(), ObjectInspector.Category.PRIMITIVE);
  PrimitiveObjectInspector primitiveInspector1 = (PrimitiveObjectInspector) inspector1;
  Assert.assertEquals(primitiveInspector1.getPrimitiveCategory(), PrimitiveCategory.LONG);

  ObjectInspector inspector2 = ((StructField) fields.get(1)).getFieldObjectInspector();
  Assert.assertEquals(inspector2.getCategory(), ObjectInspector.Category.PRIMITIVE);
  PrimitiveObjectInspector primitiveInspector2 = (PrimitiveObjectInspector) inspector2;
  Assert.assertEquals(primitiveInspector2.getPrimitiveCategory(), PrimitiveCategory.BINARY);
}
 

static void checkIntermediateResultInspector(ObjectInspector resultInspector) {
  Assert.assertNotNull(resultInspector);
  Assert.assertEquals(resultInspector.getCategory(), ObjectInspector.Category.STRUCT);
  StructObjectInspector structResultInspector = (StructObjectInspector) resultInspector;
  List<?> fields = structResultInspector.getAllStructFieldRefs();
  Assert.assertEquals(fields.size(), 3);

  ObjectInspector inspector1 = ((StructField) fields.get(0)).getFieldObjectInspector();
  Assert.assertEquals(inspector1.getCategory(), ObjectInspector.Category.PRIMITIVE);
  PrimitiveObjectInspector primitiveInspector1 = (PrimitiveObjectInspector) inspector1;
  Assert.assertEquals(primitiveInspector1.getPrimitiveCategory(), PrimitiveCategory.INT);

  ObjectInspector inspector2 = ((StructField) fields.get(1)).getFieldObjectInspector();
  Assert.assertEquals(inspector2.getCategory(), ObjectInspector.Category.PRIMITIVE);
  PrimitiveObjectInspector primitiveInspector2 = (PrimitiveObjectInspector) inspector2;
  Assert.assertEquals(primitiveInspector2.getPrimitiveCategory(), PrimitiveCategory.STRING);

  ObjectInspector inspector3 = ((StructField) fields.get(2)).getFieldObjectInspector();
  Assert.assertEquals(inspector3.getCategory(), ObjectInspector.Category.PRIMITIVE);
  PrimitiveObjectInspector primitiveInspector3 = (PrimitiveObjectInspector) inspector3;
  Assert.assertEquals(primitiveInspector3.getPrimitiveCategory(), PrimitiveCategory.BINARY);
}
 

private ObjectInspector initReduceSide(StructObjectInspector inputStructOI)
        throws HiveException {
    List<? extends StructField> fields = inputStructOI.getAllStructFieldRefs();
    int length = fields.size();
    this.inputStructOI = inputStructOI;
    this.inputOIs = new ObjectInspector[length];
    this.outputOIs = new ObjectInspector[length];

    for (int i = 0; i < length; i++) {
        StructField field = fields.get(i);
        ObjectInspector oi = field.getFieldObjectInspector();
        inputOIs[i] = oi;
        outputOIs[i] = ObjectInspectorUtils.getStandardObjectInspector(oi);
    }

    return ObjectInspectorUtils.getStandardObjectInspector(inputStructOI);
}
 

@Override
public String getTypeName() {
    StringBuilder buffer = new StringBuilder();
    buffer.append("struct<");
    for (int i = 0; i < fields.size(); ++i) {
        StructField field = fields.get(i);
        if (i != 0) {
            buffer.append(",");
        }
        buffer.append(field.getFieldName());
        buffer.append(":");
        buffer.append(field.getFieldObjectInspector().getTypeName());
    }
    buffer.append(">");
    return buffer.toString();
}
 

public static Object getStructObject(Map<String, AttributeValue> data, ObjectInspector objectInspector) {
  StructObjectInspector structOI = (StructObjectInspector) objectInspector;
  List<? extends StructField> structFields = structOI.getAllStructFieldRefs();

  List<Object> values = new ArrayList<>();
  for (StructField field : structFields) {
    values.add(getStructFieldObject(data, field));
  }

  return values;
}
 

private String getColumnNamesFromInspector(ObjectInspector inspector) {
    List<String> fieldNames = Lists.newArrayList();
    Joiner joiner = Joiner.on(",");
    if (inspector instanceof StructObjectInspector) {
        StructObjectInspector soi = (StructObjectInspector) inspector;
        List<? extends StructField> fields = soi.getAllStructFieldRefs();
        fieldNames.addAll(fields.stream().map((Function<StructField, String>) StructField::getFieldName).collect(Collectors.toList()));
    }
    return joiner.join(fieldNames);
}
 

@Override
public Object getStructFieldData( final Object object, final StructField field ){
  if( object instanceof ColumnAndIndex ){
    MDSStructField structFiled = (MDSStructField)field;
    return structFiled.getValue( (ColumnAndIndex) object );
  }
  else{
    return ( (List<Object>)object ).get( field.getFieldID() );
  }
}