org.apache.jena.hadoop.rdf.io.output.writers

Class AbstractBatchedNodeTupleWriter<TKey,TValue,T extends AbstractNodeTupleWritable<TValue>>

java.lang.Object

org.apache.hadoop.mapreduce.RecordWriter<TKey,T>

org.apache.jena.hadoop.rdf.io.output.writers.AbstractBatchedNodeTupleWriter<TKey,TValue,T>

Type Parameters:

TKey -

TValue -

T -

Direct Known Subclasses:

AbstractBatchedQuadWriter, AbstractBatchedTripleWriter

public abstract class AbstractBatchedNodeTupleWriter<TKey,TValue,T extends AbstractNodeTupleWritable<TValue>>
extends org.apache.hadoop.mapreduce.RecordWriter<TKey,T>

An abstract implementation of a record writer that writes records in batches.

It is important to note that the writer will write output periodically once sufficient tuples have been gathered. If there is an incomplete batch when the close(TaskAttemptContext) method is called then the final batch will be written then. Writing in batches increases the chances that the writer will be able to effectively use the syntax compressions of the RDF serialization being used.

The implementation only writes the value portion of the key value pair since it is the value portion that is used to convey the node tuples

Method Summary

Modifier and Type	Method and Description
void	close(org.apache.hadoop.mapreduce.TaskAttemptContext context)
void	write(TKey key, T value)

Methods inherited from class java.lang.Object

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

Method Detail

write

public final void write(TKey key,
                        T value)
                 throws IOException

Specified by:

write in class org.apache.hadoop.mapreduce.RecordWriter<TKey,T extends AbstractNodeTupleWritable<TValue>>

Throws:

IOException

close

public void close(org.apache.hadoop.mapreduce.TaskAttemptContext context)
           throws IOException

Specified by:

close in class org.apache.hadoop.mapreduce.RecordWriter<TKey,T extends AbstractNodeTupleWritable<TValue>>

Throws:

IOException