org.apache.hadoop.hive.druid.serde

Class DruidQueryRecordReader.JsonParserIterator<R extends Comparable<R>>

java.lang.Object

org.apache.hadoop.hive.druid.serde.DruidQueryRecordReader.JsonParserIterator<R>

Type Parameters:

R - druid Row type returned as result

All Implemented Interfaces:

Closeable, AutoCloseable, Iterator<R>

Enclosing class:

DruidQueryRecordReader<T extends io.druid.query.BaseQuery<R>,R extends Comparable<R>>

protected class DruidQueryRecordReader.JsonParserIterator<R extends Comparable<R>>
extends Object
implements Iterator<R>, Closeable

This is a helper wrapper class used to create an iterator of druid rows out of InputStream. The type of the rows is defined by org.apache.hadoop.hive.druid.serde.DruidQueryRecordReader.JsonParserIterator#typeRef

Constructor Summary

Constructors

Constructor and Description
JsonParserIterator(com.fasterxml.jackson.databind.ObjectMapper mapper, com.fasterxml.jackson.databind.JavaType typeRef, Future<InputStream> future, String url, io.druid.query.Query query)

Method Summary

Modifier and Type	Method and Description
void	close()
boolean	hasNext()
R	next()
void	remove()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining

Constructor Detail

JsonParserIterator

public JsonParserIterator(com.fasterxml.jackson.databind.ObjectMapper mapper,
                          com.fasterxml.jackson.databind.JavaType typeRef,
                          Future<InputStream> future,
                          String url,
                          io.druid.query.Query query)

Parameters:

mapper - mapper used to deserialize the stream of data (we use smile factory)

typeRef - Type definition of the results objects

future - Future holding the input stream (the input stream is not owned but it will be closed when org.apache.hadoop.hive.druid.serde.DruidQueryRecordReader.JsonParserIterator#close() is called or reach the end of the steam)

url - URL used to fetch the data, used mostly as message with exception stack to identify the faulty stream, thus this can be empty string.

query - Query used to fetch the data, used mostly as message with exception stack, thus can be empty string.

Method Detail

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<R extends Comparable<R>>

next

public R next()

Specified by:

next in interface Iterator<R extends Comparable<R>>

remove

public void remove()

Specified by:

remove in interface Iterator<R extends Comparable<R>>

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException