接口 org.apache.hadoop.io.WritableComparable
的使用

使用WritableComparable的程序包

程序包	说明
org.apache.hadoop.contrib.index.mapred
org.apache.hadoop.examples	Hadoop example code.
org.apache.hadoop.examples.dancing	This package is a distributed implementation of Knuth's dancing links algorithm that can run under Hadoop.
org.apache.hadoop.hdfs.protocol
org.apache.hadoop.hdfs.server.common
org.apache.hadoop.hdfs.server.namenode
org.apache.hadoop.hdfs.server.protocol
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.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.join	Given a set of sorted datasets keyed with the same class and yielding equal partitions, it is possible to effect a join of those datasets prior to the map.
org.apache.hadoop.mapred.lib	Library of generally useful mappers, reducers, and partitioners.
org.apache.hadoop.mapred.lib.aggregate	Classes for performing various counting and aggregations.
org.apache.hadoop.mapreduce
org.apache.hadoop.mapreduce.lib.output
org.apache.hadoop.mapreduce.lib.partition
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.record.meta
org.apache.hadoop.tools
org.apache.hadoop.typedbytes	Typed bytes are sequences of bytes in which the first byte is a type code.
org.apache.hadoop.util.bloom

org.apache.hadoop.contrib.index.mapred中WritableComparable的使用

类型参数类型为WritableComparable的org.apache.hadoop.contrib.index.mapred中的类

限定符和类型	接口和说明
interface	ILocalAnalysis<K extends WritableComparable,V extends Writable> Application specific local analysis.
class	IndexUpdateMapper<K extends WritableComparable,V extends Writable> This class applies local analysis on a key-value pair and then convert the result docid-operation pair to a shard-and-intermediate form pair.

实现WritableComparable的org.apache.hadoop.contrib.index.mapred中的类

限定符和类型	类和说明
class	DocumentID The class represents a document id, which is of type text.
class	Shard This class represents the metadata of a shard.

返回变量类型为WritableComparable的类型的org.apache.hadoop.contrib.index.mapred中的方法

限定符和类型	方法和说明
static Class<? extends WritableComparable>	IndexUpdateMapper.getMapOutputKeyClass() Get the map output key class.
static Class<? extends WritableComparable>	IndexUpdateReducer.getOutputKeyClass() Get the reduce output key class.

org.apache.hadoop.examples中WritableComparable的使用

实现WritableComparable的org.apache.hadoop.examples中的类

限定符和类型	类和说明
static class	MultiFileWordCount.WordOffset This record keeps <filename,offset> pairs.
static class	SecondarySort.IntPair Define a pair of integers that are writable.

类型变量类型为WritableComparable的org.apache.hadoop.examples中的方法参数

限定符和类型	方法和说明
void	PiEstimator.PiReducer.reduce(BooleanWritable isInside, Iterator<LongWritable> values, OutputCollector<WritableComparable<?>,Writable> output, Reporter reporter) Accumulate number of points inside/outside results from the mappers.

org.apache.hadoop.examples.dancing中WritableComparable的使用

参数类型为WritableComparable的org.apache.hadoop.examples.dancing中的方法

限定符和类型	方法和说明
void	DistributedPentomino.PentMap.map(WritableComparable key, Text value, OutputCollector<Text,Text> output, Reporter reporter) Break the prefix string into moves (a sequence of integer row ids that will be selected for each column in order).

org.apache.hadoop.hdfs.protocol中WritableComparable的使用

实现WritableComparable的org.apache.hadoop.hdfs.protocol中的类

限定符和类型	类和说明
class	DatanodeID DatanodeID is composed of the data node name (hostname:portNumber) and the data storage ID, which it currently represents.
class	DatanodeInfo DatanodeInfo represents the status of a DataNode.

org.apache.hadoop.hdfs.server.common中WritableComparable的使用

实现WritableComparable的org.apache.hadoop.hdfs.server.common中的类

限定符和类型	类和说明
class	GenerationStamp A GenerationStamp is a Hadoop FS primitive, identified by a long.

org.apache.hadoop.hdfs.server.namenode中WritableComparable的使用

实现WritableComparable的org.apache.hadoop.hdfs.server.namenode中的类

限定符和类型	类和说明
class	CheckpointSignature A unique signature intended to identify checkpoint transactions.
class	DatanodeDescriptor DatanodeDescriptor tracks stats on a given DataNode, such as available storage capacity, last update time, etc., and maintains a set of blocks stored on the datanode.

org.apache.hadoop.hdfs.server.protocol中WritableComparable的使用

实现WritableComparable的org.apache.hadoop.hdfs.server.protocol中的类

限定符和类型	类和说明
class	DatanodeRegistration DatanodeRegistration class conatins all information the Namenode needs to identify and verify a Datanode when it contacts the Namenode.

org.apache.hadoop.io中WritableComparable的使用

实现WritableComparable的org.apache.hadoop.io中的类

限定符和类型	类和说明
class	BooleanWritable A WritableComparable for booleans.
class	BytesWritable A byte sequence that is usable as a key or value.
class	ByteWritable A WritableComparable for a single byte.
class	DoubleWritable Writable for Double values.
class	FloatWritable A WritableComparable for floats.
class	IntWritable A WritableComparable for ints.
class	LongWritable A WritableComparable for longs.
class	MD5Hash A Writable for MD5 hash values.
class	NullWritable Singleton Writable with no data.
class	Text This class stores text using standard UTF8 encoding.
class	UTF8 已过时。 replaced by Text
class	VIntWritable A WritableComparable for integer values stored in variable-length format.
class	VLongWritable A WritableComparable for longs in a variable-length format.

返回WritableComparable的org.apache.hadoop.io中的方法

限定符和类型	方法和说明
WritableComparable	SortedMapWritable.firstKey()
WritableComparable	SetFile.Reader.get(WritableComparable key) Read the matching key from a set into key.
WritableComparable	MapFile.Reader.getClosest(WritableComparable key, Writable val) Finds the record that is the closest match to the specified key.
WritableComparable	MapFile.Reader.getClosest(WritableComparable key, Writable val, boolean before) Finds the record that is the closest match to the specified key.
WritableComparable	SortedMapWritable.lastKey()
WritableComparable	MapFile.Reader.midKey() Get the key at approximately the middle of the file.
WritableComparable	WritableComparator.newKey() Construct a new WritableComparable instance.

返回变量类型为WritableComparable的类型的org.apache.hadoop.io中的方法

限定符和类型	方法和说明
Comparator<? super WritableComparable>	SortedMapWritable.comparator()
Set<Map.Entry<WritableComparable,Writable>>	SortedMapWritable.entrySet()
Class<? extends WritableComparable>	WritableComparator.getKeyClass() Returns the WritableComparable implementation class.
SortedMap<WritableComparable,Writable>	SortedMapWritable.headMap(WritableComparable toKey)
Set<WritableComparable>	SortedMapWritable.keySet()
SortedMap<WritableComparable,Writable>	SortedMapWritable.subMap(WritableComparable fromKey, WritableComparable toKey)
SortedMap<WritableComparable,Writable>	SortedMapWritable.tailMap(WritableComparable fromKey)

参数类型为WritableComparable的org.apache.hadoop.io中的方法

限定符和类型	方法和说明
void	SetFile.Writer.append(WritableComparable key) Append a key to a set.
void	MapFile.Writer.append(WritableComparable key, Writable val) Append a key/value pair to the map.
void	BloomMapFile.Writer.append(WritableComparable key, Writable val)
int	WritableComparator.compare(WritableComparable a, WritableComparable b) Compare two WritableComparables.
int	WritableComparator.compare(WritableComparable a, WritableComparable b) Compare two WritableComparables.
int	LongWritable.DecreasingComparator.compare(WritableComparable a, WritableComparable b)
int	LongWritable.DecreasingComparator.compare(WritableComparable a, WritableComparable b)
void	MapFile.Reader.finalKey(WritableComparable key) Reads the final key from the file.
WritableComparable	SetFile.Reader.get(WritableComparable key) Read the matching key from a set into key.
Writable	MapFile.Reader.get(WritableComparable key, Writable val) Return the value for the named key, or null if none exists.
Writable	BloomMapFile.Reader.get(WritableComparable key, Writable val) Fast version of the MapFile.Reader.get(WritableComparable, Writable) method.
WritableComparable	MapFile.Reader.getClosest(WritableComparable key, Writable val) Finds the record that is the closest match to the specified key.
WritableComparable	MapFile.Reader.getClosest(WritableComparable key, Writable val, boolean before) Finds the record that is the closest match to the specified key.
SortedMap<WritableComparable,Writable>	SortedMapWritable.headMap(WritableComparable toKey)
boolean	SetFile.Reader.next(WritableComparable key) Read the next key in a set into key.
boolean	MapFile.Reader.next(WritableComparable key, Writable val) Read the next key/value pair in the map into key and val.
boolean	BloomMapFile.Reader.probablyHasKey(WritableComparable key) Checks if this MapFile has the indicated key.
Writable	SortedMapWritable.put(WritableComparable key, Writable value)
boolean	SetFile.Reader.seek(WritableComparable key)
boolean	MapFile.Reader.seek(WritableComparable key) Positions the reader at the named key, or if none such exists, at the first entry after the named key.
SortedMap<WritableComparable,Writable>	SortedMapWritable.subMap(WritableComparable fromKey, WritableComparable toKey)
SortedMap<WritableComparable,Writable>	SortedMapWritable.subMap(WritableComparable fromKey, WritableComparable toKey)
SortedMap<WritableComparable,Writable>	SortedMapWritable.tailMap(WritableComparable fromKey)

类型变量类型为WritableComparable的org.apache.hadoop.io中的方法参数

限定符和类型	方法和说明
static WritableComparator	WritableComparator.get(Class<? extends WritableComparable> c) Get a comparator for a WritableComparable implementation.
void	SortedMapWritable.putAll(Map<? extends WritableComparable,? extends Writable> t)

类型变量类型为WritableComparable的org.apache.hadoop.io中的构造器参数

构造器和说明
BloomMapFile.Writer(Configuration conf, FileSystem fs, String dirName, Class<? extends WritableComparable> keyClass, Class valClass)
BloomMapFile.Writer(Configuration conf, FileSystem fs, String dirName, Class<? extends WritableComparable> keyClass, Class<? extends Writable> valClass, SequenceFile.CompressionType compress, CompressionCodec codec, Progressable progress)
BloomMapFile.Writer(Configuration conf, FileSystem fs, String dirName, Class<? extends WritableComparable> keyClass, Class valClass, SequenceFile.CompressionType compress)
BloomMapFile.Writer(Configuration conf, FileSystem fs, String dirName, Class<? extends WritableComparable> keyClass, Class valClass, SequenceFile.CompressionType compress, Progressable progress)
MapFile.Writer(Configuration conf, FileSystem fs, String dirName, Class<? extends WritableComparable> keyClass, Class valClass) Create the named map for keys of the named class.
MapFile.Writer(Configuration conf, FileSystem fs, String dirName, Class<? extends WritableComparable> keyClass, Class valClass, SequenceFile.CompressionType compress) Create the named map for keys of the named class.
MapFile.Writer(Configuration conf, FileSystem fs, String dirName, Class<? extends WritableComparable> keyClass, Class valClass, SequenceFile.CompressionType compress, CompressionCodec codec, Progressable progress) Create the named map for keys of the named class.
MapFile.Writer(Configuration conf, FileSystem fs, String dirName, Class<? extends WritableComparable> keyClass, Class valClass, SequenceFile.CompressionType compress, Progressable progress) Create the named map for keys of the named class.
SequenceFile.Sorter(FileSystem fs, Class<? extends WritableComparable> keyClass, Class valClass, Configuration conf) Sort and merge files containing the named classes.
SetFile.Writer(Configuration conf, FileSystem fs, String dirName, Class<? extends WritableComparable> keyClass, SequenceFile.CompressionType compress) Create a set naming the element class and compression type.
SetFile.Writer(FileSystem fs, String dirName, Class<? extends WritableComparable> keyClass) 已过时。 pass a Configuration too
WritableComparator(Class<? extends WritableComparable> keyClass) Construct for a WritableComparable implementation.
WritableComparator(Class<? extends WritableComparable> keyClass, boolean createInstances)

org.apache.hadoop.mapred中WritableComparable的使用

类型参数类型为WritableComparable的org.apache.hadoop.mapred中的方法

限定符和类型	方法和说明
static <K extends WritableComparable,V extends Writable> Writable	MapFileOutputFormat.getEntry(MapFile.Reader[] readers, Partitioner<K,V> partitioner, K key, V value) Get an entry from output generated by this class.

返回变量类型为WritableComparable的类型的org.apache.hadoop.mapred中的方法

限定符和类型	方法和说明
RecordWriter<WritableComparable,Writable>	MapFileOutputFormat.getRecordWriter(FileSystem ignored, JobConf job, String name, Progressable progress)
static Class<? extends WritableComparable>	SequenceFileAsBinaryOutputFormat.getSequenceFileOutputKeyClass(JobConf conf) Get the key class for the SequenceFile

org.apache.hadoop.mapred.join中WritableComparable的使用

类型参数类型为WritableComparable的org.apache.hadoop.mapred.join中的类

限定符和类型	接口和说明
interface	ComposableInputFormat<K extends WritableComparable,V extends Writable> Refinement of InputFormat requiring implementors to provide ComposableRecordReader instead of RecordReader.
interface	ComposableRecordReader<K extends WritableComparable,V extends Writable> Additional operations required of a RecordReader to participate in a join.
class	CompositeInputFormat<K extends WritableComparable> An InputFormat capable of performing joins over a set of data sources sorted and partitioned the same way.
class	CompositeRecordReader<K extends WritableComparable,V extends Writable,X extends Writable> A RecordReader that can effect joins of RecordReaders sharing a common key type and partitioning.
class	InnerJoinRecordReader<K extends WritableComparable> Full inner join.
class	JoinRecordReader<K extends WritableComparable> Base class for Composite joins returning Tuples of arbitrary Writables.
class	MultiFilterRecordReader<K extends WritableComparable,V extends Writable> Base class for Composite join returning values derived from multiple sources, but generally not tuples.
class	OuterJoinRecordReader<K extends WritableComparable> Full outer join.
class	OverrideRecordReader<K extends WritableComparable,V extends Writable> Prefer the "rightmost" data source for this key.
class	WrappedRecordReader<K extends WritableComparable,U extends Writable> Proxy class for a RecordReader participating in the join framework.

org.apache.hadoop.mapred.lib中WritableComparable的使用

类型参数类型为WritableComparable的org.apache.hadoop.mapred.lib中的类

限定符和类型	类和说明
class	TotalOrderPartitioner<K extends WritableComparable,V> Partitioner effecting a total order by reading split points from an externally generated source.

返回变量类型为WritableComparable的类型的org.apache.hadoop.mapred.lib中的方法

限定符和类型	方法和说明
static Class<? extends WritableComparable>	MultipleOutputs.getNamedOutputKeyClass(JobConf conf, String namedOutput) Returns the key class for a named output.

org.apache.hadoop.mapred.lib.aggregate中WritableComparable的使用

类型参数类型为WritableComparable的org.apache.hadoop.mapred.lib.aggregate中的类

限定符和类型	类和说明
class	ValueAggregatorCombiner<K1 extends WritableComparable,V1 extends Writable> This class implements the generic combiner of Aggregate.
class	ValueAggregatorJobBase<K1 extends WritableComparable,V1 extends Writable> This abstract class implements some common functionalities of the the generic mapper, reducer and combiner classes of Aggregate.
class	ValueAggregatorMapper<K1 extends WritableComparable,V1 extends Writable> This class implements the generic mapper of Aggregate.
class	ValueAggregatorReducer<K1 extends WritableComparable,V1 extends Writable> This class implements the generic reducer of Aggregate.

org.apache.hadoop.mapreduce中WritableComparable的使用

实现WritableComparable的org.apache.hadoop.mapreduce中的类

限定符和类型	类和说明
class	ID A general identifier, which internally stores the id as an integer.
class	JobID JobID represents the immutable and unique identifier for the job.
class	TaskAttemptID TaskAttemptID represents the immutable and unique identifier for a task attempt.
class	TaskID TaskID represents the immutable and unique identifier for a Map or Reduce Task.

org.apache.hadoop.mapreduce.lib.output中WritableComparable的使用

返回变量类型为WritableComparable的类型的org.apache.hadoop.mapreduce.lib.output中的方法

限定符和类型	方法和说明
static Class<? extends WritableComparable>	SequenceFileAsBinaryOutputFormat.getSequenceFileOutputKeyClass(JobContext job) Get the key class for the SequenceFile

org.apache.hadoop.mapreduce.lib.partition中WritableComparable的使用

类型参数类型为WritableComparable的org.apache.hadoop.mapreduce.lib.partition中的类

限定符和类型	类和说明
class	TotalOrderPartitioner<K extends WritableComparable<?>,V> Partitioner effecting a total order by reading split points from an externally generated source.

org.apache.hadoop.record中WritableComparable的使用

实现WritableComparable的org.apache.hadoop.record中的类

限定符和类型	类和说明
class	Record Abstract class that is extended by generated classes.

类型变量类型为WritableComparable的org.apache.hadoop.record中的构造器参数

构造器和说明
RecordComparator(Class<? extends WritableComparable> recordClass) Construct a raw Record comparison implementation.

org.apache.hadoop.record.meta中WritableComparable的使用

实现WritableComparable的org.apache.hadoop.record.meta中的类

限定符和类型	类和说明
class	RecordTypeInfo A record's Type Information object which can read/write itself.

org.apache.hadoop.tools中WritableComparable的使用

类型参数类型为WritableComparable的org.apache.hadoop.tools中的类

限定符和类型	类和说明
static class	Logalyzer.LogRegexMapper<K extends WritableComparable> A Mapper that extracts text matching a regular expression.

org.apache.hadoop.typedbytes中WritableComparable的使用

实现WritableComparable的org.apache.hadoop.typedbytes中的类

限定符和类型	类和说明
class	TypedBytesWritable Writable for typed bytes.

org.apache.hadoop.util.bloom中WritableComparable的使用

实现WritableComparable的org.apache.hadoop.util.bloom中的类

限定符和类型	类和说明
class	Key The general behavior of a key that must be stored in a filter.