| 程序包 | 说明 |
|---|---|
| org.apache.hadoop.examples |
Hadoop example code.
|
| 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 |
A software framework for easily writing applications which process vast
amounts of data (multi-terabyte data-sets) parallelly on large clusters
(thousands of nodes) built of commodity hardware in a reliable, fault-tolerant
manner.
|
| org.apache.hadoop.mapred.lib |
Library of generally useful mappers, reducers, and partitioners.
|
| org.apache.hadoop.mapreduce | |
| org.apache.hadoop.record |
Hadoop record I/O contains classes and a record description language
translator for simplifying serialization and deserialization of records in a
language-neutral manner.
|
| org.apache.hadoop.tools |
| 限定符和类型 | 类和说明 |
|---|---|
static class |
SecondarySort.FirstGroupingComparator
Compare only the first part of the pair, so that reduce is called once
for each value of the first part.
|
static class |
SecondarySort.IntPair.Comparator
A Comparator that compares serialized IntPair.
|
| 限定符和类型 | 类和说明 |
|---|---|
static class |
BooleanWritable.Comparator
A Comparator optimized for BooleanWritable.
|
static class |
BytesWritable.Comparator
A Comparator optimized for BytesWritable.
|
static class |
ByteWritable.Comparator
A Comparator optimized for ByteWritable.
|
static class |
DoubleWritable.Comparator
A Comparator optimized for DoubleWritable.
|
static class |
FloatWritable.Comparator
A Comparator optimized for FloatWritable.
|
static class |
IntWritable.Comparator
A Comparator optimized for IntWritable.
|
static class |
LongWritable.Comparator
A Comparator optimized for LongWritable.
|
static class |
LongWritable.DecreasingComparator
A decreasing Comparator optimized for LongWritable.
|
static class |
MD5Hash.Comparator
A WritableComparator optimized for MD5Hash keys.
|
static class |
NullWritable.Comparator
A Comparator "optimized" for NullWritable.
|
static class |
Text.Comparator
A WritableComparator optimized for Text keys.
|
static class |
UTF8.Comparator
已过时。
A WritableComparator optimized for UTF8 keys.
|
class |
WritableComparator
A Comparator for
WritableComparables. |
| 构造器和说明 |
|---|
SequenceFile.Sorter(FileSystem fs,
RawComparator comparator,
Class keyClass,
Class valClass,
Configuration conf)
Sort and merge using an arbitrary
RawComparator. |
| 限定符和类型 | 类和说明 |
|---|---|
class |
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. |
| 限定符和类型 | 方法和说明 |
|---|---|
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. |
| 限定符和类型 | 方法和说明 |
|---|---|
protected static <INKEY,INVALUE,OUTKEY,OUTVALUE> |
Task.createReduceContext(Reducer<INKEY,INVALUE,OUTKEY,OUTVALUE> reducer,
Configuration job,
TaskAttemptID taskId,
RawKeyValueIterator rIter,
Counter inputKeyCounter,
Counter inputValueCounter,
RecordWriter<OUTKEY,OUTVALUE> output,
OutputCommitter committer,
StatusReporter reporter,
RawComparator<INKEY> comparator,
Class<INKEY> keyClass,
Class<INVALUE> valueClass) |
| 限定符和类型 | 方法和说明 |
|---|---|
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. |
| 构造器和说明 |
|---|
Task.CombineValuesIterator(RawKeyValueIterator in,
RawComparator<KEY> comparator,
Class<KEY> keyClass,
Class<VALUE> valClass,
Configuration conf,
Reporter reporter,
Counters.Counter combineInputCounter) |
| 限定符和类型 | 类和说明 |
|---|---|
class |
KeyFieldBasedComparator<K,V>
This comparator implementation provides a subset of the features provided
by the Unix/GNU Sort.
|
| 限定符和类型 | 方法和说明 |
|---|---|
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. |
| 限定符和类型 | 方法和说明 |
|---|---|
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. |
| 构造器和说明 |
|---|
ReduceContext(Configuration conf,
TaskAttemptID taskid,
RawKeyValueIterator input,
Counter inputKeyCounter,
Counter inputValueCounter,
RecordWriter<KEYOUT,VALUEOUT> output,
OutputCommitter committer,
StatusReporter reporter,
RawComparator<KEYIN> comparator,
Class<KEYIN> keyClass,
Class<VALUEIN> valueClass) |
Reducer.Context(Configuration conf,
TaskAttemptID taskid,
RawKeyValueIterator input,
Counter inputKeyCounter,
Counter inputValueCounter,
RecordWriter<KEYOUT,VALUEOUT> output,
OutputCommitter committer,
StatusReporter reporter,
RawComparator<KEYIN> comparator,
Class<KEYIN> keyClass,
Class<VALUEIN> valueClass) |
| 限定符和类型 | 类和说明 |
|---|---|
class |
RecordComparator
A raw record comparator base class
|
| 限定符和类型 | 类和说明 |
|---|---|
static class |
Logalyzer.LogComparator
A WritableComparator optimized for UTF8 keys of the logs.
|
Copyright © 2009 The Apache Software Foundation