Package | Description |
---|---|
org.apache.hadoop.io |
Generic i/o code for use when reading and writing data to the network,
to databases, and to files.
|
org.apache.hadoop.io.serializer |
This package provides a mechanism for using different serialization frameworks
in Hadoop.
|
org.apache.hadoop.mapred | |
org.apache.hadoop.mapreduce | |
org.apache.hadoop.mapreduce.lib.partition | |
org.apache.hadoop.record |
(DEPRECATED) Hadoop record I/O contains classes and a record description language
translator for simplifying serialization and deserialization of records in a
language-neutral manner.
|
Modifier and Type | Class and Description |
---|---|
class |
WritableComparator
A Comparator for
WritableComparable s. |
Modifier and Type | Class and Description |
---|---|
class |
org.apache.hadoop.io.serializer.DeserializerComparator<T>
A
RawComparator that uses a Deserializer to deserialize
the objects to be compared so that the standard Comparator can
be used to compare them. |
class |
JavaSerializationComparator<T extends Serializable & Comparable<T>>
A
RawComparator that uses a JavaSerialization
Deserializer to deserialize objects that are then compared via
their Comparable interfaces. |
Modifier and Type | Method and Description |
---|---|
RawComparator |
JobConf.getCombinerKeyGroupingComparator()
Get the user defined
WritableComparable comparator for
grouping keys of inputs to the combiner. |
RawComparator |
JobConf.getOutputKeyComparator()
Get the
RawComparator comparator used to compare keys. |
RawComparator |
JobConf.getOutputValueGroupingComparator()
Get the user defined
WritableComparable comparator for
grouping keys of inputs to the reduce. |
Modifier and Type | Method and Description |
---|---|
void |
JobConf.setCombinerKeyGroupingComparator(Class<? extends RawComparator> theClass)
Set the user defined
RawComparator comparator for
grouping keys in the input to the combiner. |
void |
JobConf.setOutputKeyComparatorClass(Class<? extends RawComparator> theClass)
Set the
RawComparator comparator used to compare keys. |
void |
JobConf.setOutputValueGroupingComparator(Class<? extends RawComparator> theClass)
Set the user defined
RawComparator comparator for
grouping keys in the input to the reduce. |
Modifier and Type | Method and Description |
---|---|
RawComparator<?> |
JobContext.getCombinerKeyGroupingComparator()
Get the user defined
RawComparator comparator for
grouping keys of inputs to the combiner. |
RawComparator<?> |
JobContext.getGroupingComparator()
Get the user defined
RawComparator comparator for
grouping keys of inputs to the reduce. |
RawComparator<?> |
JobContext.getSortComparator()
Get the
RawComparator comparator used to compare keys. |
Modifier and Type | Method and Description |
---|---|
void |
Job.setCombinerKeyGroupingComparatorClass(Class<? extends RawComparator> cls)
Define the comparator that controls which keys are grouped together
for a single call to combiner,
Reducer.reduce(Object, Iterable,
org.apache.hadoop.mapreduce.Reducer.Context) |
void |
Job.setGroupingComparatorClass(Class<? extends RawComparator> cls)
Define the comparator that controls which keys are grouped together
for a single call to
Reducer.reduce(Object, Iterable,
org.apache.hadoop.mapreduce.Reducer.Context) |
void |
Job.setSortComparatorClass(Class<? extends RawComparator> cls)
Define the comparator that controls how the keys are sorted before they
are passed to the
Reducer . |
Modifier and Type | Class and Description |
---|---|
class |
KeyFieldBasedComparator<K,V>
This comparator implementation provides a subset of the features provided
by the Unix/GNU Sort.
|
Modifier and Type | Class and Description |
---|---|
class |
RecordComparator
Deprecated.
Replaced by Avro.
|
Copyright © 2015 Apache Software Foundation. All rights reserved.