org.apache.drill.exec.store.pojo

Class DynamicPojoRecordReader<T>

java.lang.Object

org.apache.drill.exec.store.AbstractRecordReader

org.apache.drill.exec.store.pojo.AbstractPojoRecordReader<List<T>>

org.apache.drill.exec.store.pojo.DynamicPojoRecordReader<T>

Type Parameters:

T - type of given values, if contains various types, use Object class

All Implemented Interfaces:

AutoCloseable, Iterable<List<T>>, RecordReader

public class DynamicPojoRecordReader<T>
extends AbstractPojoRecordReader<List<T>>

Dynamically reads values from the given list of records. Creates writers based on given schema.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DynamicPojoRecordReader.Converter An utility class that converts from JsonNode to DynamicPojoRecordReader during physical plan fragment deserialization.

Field Summary

Fields inherited from class org.apache.drill.exec.store.pojo.AbstractPojoRecordReader

DEFAULT_RECORDS_PER_BATCH, records, writers

Fields inherited from class org.apache.drill.exec.store.AbstractRecordReader

DEFAULT_TEXT_COLS_TO_READ

Fields inherited from interface org.apache.drill.exec.store.RecordReader

ALLOCATOR_INITIAL_RESERVATION, ALLOCATOR_MAX_RESERVATION

Constructor Summary

Constructors

Constructor and Description
DynamicPojoRecordReader(LinkedHashMap<String,Class<?>> schema, List<List<T>> records)
DynamicPojoRecordReader(LinkedHashMap<String,Class<?>> schema, List<List<T>> records, int maxRecordsToRead)

Method Summary

Modifier and Type	Method and Description
protected Object	getFieldValue(List<T> row, int fieldPosition) Retrieves field value to be written based for given row and field position.
protected List<PojoWriter>	setupWriters(OutputMutator output) Initiates writers based on given schema which contains field name and its type.
String	toString()

Methods inherited from class org.apache.drill.exec.store.pojo.AbstractPojoRecordReader

allocate, close, initWriter, iterator, next, setup

Methods inherited from class org.apache.drill.exec.store.AbstractRecordReader

getColumns, getDefaultColumnsToRead, hasNext, isSkipQuery, isStarQuery, setColumns, transformColumns

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

DynamicPojoRecordReader

public DynamicPojoRecordReader(LinkedHashMap<String,Class<?>> schema,
                               List<List<T>> records)

DynamicPojoRecordReader

public DynamicPojoRecordReader(LinkedHashMap<String,Class<?>> schema,
                               List<List<T>> records,
                               int maxRecordsToRead)

Method Detail

setupWriters

protected List<PojoWriter> setupWriters(OutputMutator output)
                                 throws ExecutionSetupException

Initiates writers based on given schema which contains field name and its type.

Specified by:

setupWriters in class AbstractPojoRecordReader<List<T>>

Parameters:

output - output mutator

Returns:

list of pojo writers

Throws:

ExecutionSetupException

getFieldValue

protected Object getFieldValue(List<T> row,
                               int fieldPosition)

Description copied from class: AbstractPojoRecordReader

Retrieves field value to be written based for given row and field position.

Specified by:

getFieldValue in class AbstractPojoRecordReader<List<T>>

Parameters:

row - current row

fieldPosition - current field position

Returns:

field value to be written for given row

toString

public String toString()

Overrides:

toString in class AbstractRecordReader