org.apache.hadoop.mapreduce.lib.join
Class JoinRecordReader<K extends org.apache.hadoop.io.WritableComparable<?>>
java.lang.Object
org.apache.hadoop.mapreduce.RecordReader<K,V>
org.apache.hadoop.mapreduce.lib.join.ComposableRecordReader<K,X>
org.apache.hadoop.mapreduce.lib.join.CompositeRecordReader<K,org.apache.hadoop.io.Writable,TupleWritable>
org.apache.hadoop.mapreduce.lib.join.JoinRecordReader<K>
- All Implemented Interfaces:
- Closeable, Comparable<ComposableRecordReader<K,?>>, org.apache.hadoop.conf.Configurable
- Direct Known Subclasses:
- InnerJoinRecordReader, OuterJoinRecordReader
@InterfaceAudience.Public
@InterfaceStability.Stable
public abstract class JoinRecordReader<K extends org.apache.hadoop.io.WritableComparable<?>>
- extends CompositeRecordReader<K,org.apache.hadoop.io.Writable,TupleWritable>
Base class for Composite joins returning Tuples of arbitrary Writables.
Constructor Summary |
JoinRecordReader(int id,
org.apache.hadoop.conf.Configuration conf,
int capacity,
Class<? extends org.apache.hadoop.io.WritableComparator> cmpcl)
|
Methods inherited from class org.apache.hadoop.mapreduce.lib.join.CompositeRecordReader |
accept, add, close, combine, compareTo, createKey, createTupleWritable, fillJoinCollector, getComparator, getConf, getCurrentKey, getCurrentValue, getProgress, getRecordReaderQueue, hasNext, id, initialize, key, key, setConf, skip |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
JoinRecordReader
public JoinRecordReader(int id,
org.apache.hadoop.conf.Configuration conf,
int capacity,
Class<? extends org.apache.hadoop.io.WritableComparator> cmpcl)
throws IOException
- Throws:
IOException
nextKeyValue
public boolean nextKeyValue()
throws IOException,
InterruptedException
- Emit the next set of key, value pairs as defined by the child
RecordReaders and operation associated with this composite RR.
- Specified by:
nextKeyValue
in class RecordReader<K extends org.apache.hadoop.io.WritableComparable<?>,TupleWritable>
- Returns:
- true if a key/value pair was read
- Throws:
IOException
InterruptedException
createValue
public TupleWritable createValue()
- Description copied from class:
ComposableRecordReader
- Create instance of value.
getDelegate
protected ResetableIterator<TupleWritable> getDelegate()
- Return an iterator wrapping the JoinCollector.
- Specified by:
getDelegate
in class CompositeRecordReader<K extends org.apache.hadoop.io.WritableComparable<?>,org.apache.hadoop.io.Writable,TupleWritable>
Copyright © 2012 Apache Software Foundation. All Rights Reserved.