接口 org.apache.hadoop.io.Writable
的使用

使用Writable的程序包

程序包	说明
org.apache.hadoop.conf	Configuration of system parameters.
org.apache.hadoop.contrib.index.example
org.apache.hadoop.contrib.index.mapred
org.apache.hadoop.contrib.utils.join
org.apache.hadoop.examples	Hadoop example code.
org.apache.hadoop.fs	An abstract file system API.
org.apache.hadoop.fs.permission
org.apache.hadoop.hdfs.protocol
org.apache.hadoop.hdfs.security.token.block
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.io.serializer	This package provides a mechanism for using different serialization frameworks in Hadoop.
org.apache.hadoop.ipc	Tools to help define network clients and servers.
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.mapred.lib.db	org.apache.hadoop.mapred.lib.db Package This package contains a library to read records from a database as an input to a mapreduce job, and write the output records to the database.
org.apache.hadoop.mapreduce
org.apache.hadoop.mapreduce.lib.db
org.apache.hadoop.mapreduce.lib.output
org.apache.hadoop.mapreduce.security.token
org.apache.hadoop.mapreduce.security.token.delegation
org.apache.hadoop.mapreduce.split
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.security
org.apache.hadoop.security.authorize
org.apache.hadoop.security.token
org.apache.hadoop.security.token.delegation
org.apache.hadoop.streaming.io
org.apache.hadoop.tools.rumen	Rumen is a data extraction and analysis tool built for Apache Hadoop.
org.apache.hadoop.typedbytes	Typed bytes are sequences of bytes in which the first byte is a type code.
org.apache.hadoop.util	Common utilities.
org.apache.hadoop.util.bloom

org.apache.hadoop.conf中Writable的使用

实现Writable的org.apache.hadoop.conf中的类

限定符和类型	类和说明
class	Configuration Provides access to configuration parameters.

org.apache.hadoop.contrib.index.example中Writable的使用

实现Writable的org.apache.hadoop.contrib.index.example中的类

限定符和类型	类和说明
class	LineDocTextAndOp This class represents an operation.

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

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

限定符和类型	类和说明
class	DocumentAndOp This class represents an indexing operation.
class	DocumentID The class represents a document id, which is of type text.
class	IntermediateForm An intermediate form for one or more parsed Lucene documents and/or delete terms.
class	Shard This class represents the metadata of a shard.

返回变量类型为Writable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 Writable>	IndexUpdateMapper.getMapOutputValueClass() Get the map output value class.
static Class<? extends Writable>	IndexUpdateReducer.getOutputValueClass() Get the reduce output value class.

org.apache.hadoop.contrib.utils.join中Writable的使用

实现Writable的org.apache.hadoop.contrib.utils.join中的类

限定符和类型	类和说明
class	TaggedMapOutput This abstract class serves as the base class for the values that flow from the mappers to the reducers in a data join job.

返回Writable的org.apache.hadoop.contrib.utils.join中的方法

限定符和类型	方法和说明
abstract Writable	TaggedMapOutput.getData()

org.apache.hadoop.examples中Writable的使用

实现Writable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.
static class	SleepJob.EmptySplit

类型变量类型为Writable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.fs中Writable的使用

实现Writable的org.apache.hadoop.fs中的类

限定符和类型	类和说明
class	BlockLocation
class	ContentSummary Store the summary of a content (a directory or a file).
class	FileChecksum An abstract class representing file checksums for files.
class	FileStatus Interface that represents the client side information for a file.
class	MD5MD5CRC32FileChecksum MD5 of MD5 of CRC32.

org.apache.hadoop.fs.permission中Writable的使用

实现Writable的org.apache.hadoop.fs.permission中的类

限定符和类型	类和说明
class	FsPermission A class for file/directory permissions.
class	PermissionStatus Store permission related information.

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

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

限定符和类型	类和说明
class	Block A Block is a Hadoop FS primitive, identified by a long.
class	BlockLocalPathInfo A block and the full path information to the block data file and the metadata file stored on the local file system.
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.
static class	DataTransferProtocol.PipelineAck reply
class	DirectoryListing This class defines a partial listing of a directory to support iterative directory listing.
class	HdfsFileStatus Interface that represents the over the wire information for a file.
class	LocatedBlock A LocatedBlock is a pair of Block, DatanodeInfo[] objects.
class	LocatedBlocks Collection of blocks with their locations and the file length.

org.apache.hadoop.hdfs.security.token.block中Writable的使用

实现Writable的org.apache.hadoop.hdfs.security.token.block中的类

限定符和类型	类和说明
class	BlockKey Key used for generating and verifying block tokens
class	BlockTokenIdentifier
class	ExportedBlockKeys Object for passing block keys

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

实现Writable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.
class	UpgradeStatusReport Base upgrade upgradeStatus class.

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

实现Writable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Writable的使用

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

限定符和类型	类和说明
class	BalancerBandwidthCommand Balancer bandwidth command instructs each datanode to change its value for the max amount of network bandwidth it may use during the block balancing operation.
class	BlockCommand A BlockCommand is an instruction to a datanode regarding some blocks under its control.
class	BlockMetaDataInfo Meta data information for a block
class	BlockRecoveryInfo
class	BlocksWithLocations A class to implement an array of BlockLocations It provide efficient customized serialization/deserialization methods in stead of using the default array (de)serialization provided by RPC
static class	BlocksWithLocations.BlockWithLocations A class to keep track of a block and its locations
class	DatanodeCommand
class	DatanodeRegistration DatanodeRegistration class conatins all information the Namenode needs to identify and verify a Datanode when it contacts the Namenode.
class	KeyUpdateCommand
class	NamespaceInfo NamespaceInfo is returned by the name-node in reply to a data-node handshake.
class	UpgradeCommand This as a generic distributed upgrade command.

org.apache.hadoop.io中Writable的使用

org.apache.hadoop.io中Writable的子接口

限定符和类型	接口和说明
interface	WritableComparable<T> A Writable which is also Comparable.

实现Writable的org.apache.hadoop.io中的类

限定符和类型	类和说明
class	AbstractMapWritable Abstract base class for MapWritable and SortedMapWritable Unlike org.apache.nutch.crawl.MapWritable, this class allows creation of MapWritable<Writable, MapWritable> so the CLASS_TO_ID and ID_TO_CLASS maps travel with the class instead of being static.
class	ArrayWritable A Writable for arrays containing instances of a class.
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	CompressedWritable A base-class for Writables which store themselves compressed and lazily inflate on field access.
class	DoubleWritable Writable for Double values.
class	FloatWritable A WritableComparable for floats.
class	GenericWritable A wrapper for Writable instances.
class	IntWritable A WritableComparable for ints.
class	LongWritable A WritableComparable for longs.
class	MapWritable A Writable Map.
class	MD5Hash A Writable for MD5 hash values.
class	NullWritable Singleton Writable with no data.
class	ObjectWritable A polymorphic Writable that writes an instance with it's class name.
static class	SequenceFile.Metadata The class encapsulating with the metadata of a file.
class	SortedMapWritable A Writable SortedMap.
class	Text This class stores text using standard UTF8 encoding.
class	TwoDArrayWritable A Writable for 2D arrays containing a matrix of instances of a class.
class	UTF8 已过时。 replaced by Text
class	VersionedWritable A base class for Writables that provides version checking.
class	VIntWritable A WritableComparable for integer values stored in variable-length format.
class	VLongWritable A WritableComparable for longs in a variable-length format.

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

限定符和类型	方法和说明
static <T extends Writable> T	WritableUtils.clone(T orig, Configuration conf) Make a copy of a writable object using serialization to a buffer.

返回Writable的org.apache.hadoop.io中的方法

限定符和类型	方法和说明
Writable[][]	TwoDArrayWritable.get()
Writable	GenericWritable.get() Return the wrapped instance.
Writable[]	ArrayWritable.get()
Writable	ArrayFile.Reader.get(long n, Writable value) Return the nth value in the file.
Writable	SortedMapWritable.get(Object key)
Writable	MapWritable.get(Object 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.
Writable	WritableFactory.newInstance() Return a new instance.
static Writable	WritableFactories.newInstance(Class<? extends Writable> c) Create a new instance of a class with a defined factory.
static Writable	WritableFactories.newInstance(Class<? extends Writable> c, Configuration conf) Create a new instance of a class with a defined factory.
Writable	ArrayFile.Reader.next(Writable value) Read and return the next value in the file.
Writable	SortedMapWritable.put(WritableComparable key, Writable value)
Writable	MapWritable.put(Writable key, Writable value)
Writable	SortedMapWritable.remove(Object key)
Writable	MapWritable.remove(Object key)

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

限定符和类型	方法和说明
Set<Map.Entry<WritableComparable,Writable>>	SortedMapWritable.entrySet()
Set<Map.Entry<Writable,Writable>>	MapWritable.entrySet()
Set<Map.Entry<Writable,Writable>>	MapWritable.entrySet()
SortedMap<WritableComparable,Writable>	SortedMapWritable.headMap(WritableComparable toKey)
Set<Writable>	MapWritable.keySet()
SortedMap<WritableComparable,Writable>	SortedMapWritable.subMap(WritableComparable fromKey, WritableComparable toKey)
SortedMap<WritableComparable,Writable>	SortedMapWritable.tailMap(WritableComparable fromKey)
Collection<Writable>	SortedMapWritable.values()
Collection<Writable>	MapWritable.values()

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

限定符和类型	方法和说明
void	ArrayFile.Writer.append(Writable value) Append a value to the file.
void	MapFile.Writer.append(WritableComparable key, Writable val) Append a key/value pair to the map.
void	BloomMapFile.Writer.append(WritableComparable key, Writable val)
void	SequenceFile.Writer.append(Writable key, Writable val) Append a key/value pair.
static void	WritableUtils.cloneInto(Writable dst, Writable src) 已过时。 use ReflectionUtils.cloneInto instead.
protected void	AbstractMapWritable.copy(Writable other) Used by child copy constructors.
Writable	ArrayFile.Reader.get(long n, Writable value) Return the nth value in the file.
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.
void	SequenceFile.Reader.getCurrentValue(Writable val) Get the 'value' corresponding to the last read 'key'.
boolean	SequenceFile.Reader.next(Writable key) Read the next key in the file into key, skipping its value.
Writable	ArrayFile.Reader.next(Writable value) Read and return the next value in the file.
boolean	MapFile.Reader.next(WritableComparable key, Writable val) Read the next key/value pair in the map into key and val.
boolean	SequenceFile.Reader.next(Writable key, Writable val) Read the next key/value pair in the file into key and val.
Writable	SortedMapWritable.put(WritableComparable key, Writable value)
Writable	MapWritable.put(Writable key, Writable value)
void	GenericWritable.set(Writable obj) Set the instance that is wrapped.
void	ArrayWritable.set(Writable[] values)
void	TwoDArrayWritable.set(Writable[][] values)
static byte[]	WritableUtils.toByteArray(Writable... writables) Convert writables to a byte array

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

限定符和类型	方法和说明
static long	MapFile.fix(FileSystem fs, Path dir, Class<? extends Writable> keyClass, Class<? extends Writable> valueClass, boolean dryrun, Configuration conf) This method attempts to fix a corrupt MapFile by re-creating its index.
static long	MapFile.fix(FileSystem fs, Path dir, Class<? extends Writable> keyClass, Class<? extends Writable> valueClass, boolean dryrun, Configuration conf) This method attempts to fix a corrupt MapFile by re-creating its index.
static Writable	WritableFactories.newInstance(Class<? extends Writable> c) Create a new instance of a class with a defined factory.
static Writable	WritableFactories.newInstance(Class<? extends Writable> c, Configuration conf) Create a new instance of a class with a defined factory.
void	MapWritable.putAll(Map<? extends Writable,? extends Writable> t)
void	MapWritable.putAll(Map<? extends Writable,? extends Writable> t)
void	SortedMapWritable.putAll(Map<? extends WritableComparable,? extends Writable> t)

参数类型为Writable的org.apache.hadoop.io中的构造器

构造器和说明
ArrayWritable(Class<? extends Writable> valueClass, Writable[] values)
TwoDArrayWritable(Class valueClass, Writable[][] values)

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

构造器和说明
ArrayFile.Writer(Configuration conf, FileSystem fs, String file, Class<? extends Writable> valClass) Create the named file for values of the named class.
ArrayFile.Writer(Configuration conf, FileSystem fs, String file, Class<? extends Writable> valClass, SequenceFile.CompressionType compress, Progressable progress) Create the named file for values of the named class.
ArrayWritable(Class<? extends Writable> valueClass)
ArrayWritable(Class<? extends Writable> valueClass, Writable[] values)
BloomMapFile.Writer(Configuration conf, FileSystem fs, String dirName, Class<? extends WritableComparable> keyClass, Class<? extends Writable> valClass, SequenceFile.CompressionType compress, CompressionCodec codec, Progressable progress)

org.apache.hadoop.io.serializer中Writable的使用

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

限定符和类型	方法和说明
Deserializer<Writable>	WritableSerialization.getDeserializer(Class<Writable> c)
Serializer<Writable>	WritableSerialization.getSerializer(Class<Writable> c)

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

限定符和类型	方法和说明
Deserializer<Writable>	WritableSerialization.getDeserializer(Class<Writable> c)
Serializer<Writable>	WritableSerialization.getSerializer(Class<Writable> c)

org.apache.hadoop.ipc中Writable的使用

返回Writable的org.apache.hadoop.ipc中的方法

限定符和类型	方法和说明
abstract Writable	Server.call(Class<?> protocol, Writable param, long receiveTime) Called for each call.
Writable	RPC.Server.call(Class<?> protocol, Writable param, long receivedTime)
Writable[]	Client.call(Writable[] params, InetSocketAddress[] addresses) 已过时。 Use Client.call(Writable[], InetSocketAddress[], Class, UserGroupInformation, Configuration) instead
Writable[]	Client.call(Writable[] params, InetSocketAddress[] addresses, Class<?> protocol, UserGroupInformation ticket) 已过时。 Use Client.call(Writable[], InetSocketAddress[], Class, UserGroupInformation, Configuration) instead
Writable[]	Client.call(Writable[] params, InetSocketAddress[] addresses, Class<?> protocol, UserGroupInformation ticket, Configuration conf) Makes a set of calls in parallel.
Writable	Client.call(Writable param, org.apache.hadoop.ipc.Client.ConnectionId remoteId) Make a call, passing param, to the IPC server defined by remoteId, returning the value.
Writable	Client.call(Writable param, InetSocketAddress address) 已过时。 Use Client.call(Writable, ConnectionId) instead
Writable	Client.call(Writable param, InetSocketAddress addr, Class<?> protocol, UserGroupInformation ticket, int rpcTimeout) 已过时。 Use Client.call(Writable, ConnectionId) instead
Writable	Client.call(Writable param, InetSocketAddress addr, Class<?> protocol, UserGroupInformation ticket, int rpcTimeout, Configuration conf) Make a call, passing param, to the IPC server running at address which is servicing the protocol protocol, with the ticket credentials, rpcTimeout as timeout and conf as configuration for this connection, returning the value.
Writable	Client.call(Writable param, InetSocketAddress addr, UserGroupInformation ticket) 已过时。 Use Client.call(Writable, ConnectionId) instead
Writable	Server.call(Writable param, long receiveTime) 已过时。 Use Server.call(Class, Writable, long) instead

参数类型为Writable的org.apache.hadoop.ipc中的方法

限定符和类型	方法和说明
abstract Writable	Server.call(Class<?> protocol, Writable param, long receiveTime) Called for each call.
Writable	RPC.Server.call(Class<?> protocol, Writable param, long receivedTime)
Writable[]	Client.call(Writable[] params, InetSocketAddress[] addresses) 已过时。 Use Client.call(Writable[], InetSocketAddress[], Class, UserGroupInformation, Configuration) instead
Writable[]	Client.call(Writable[] params, InetSocketAddress[] addresses, Class<?> protocol, UserGroupInformation ticket) 已过时。 Use Client.call(Writable[], InetSocketAddress[], Class, UserGroupInformation, Configuration) instead
Writable[]	Client.call(Writable[] params, InetSocketAddress[] addresses, Class<?> protocol, UserGroupInformation ticket, Configuration conf) Makes a set of calls in parallel.
Writable	Client.call(Writable param, org.apache.hadoop.ipc.Client.ConnectionId remoteId) Make a call, passing param, to the IPC server defined by remoteId, returning the value.
Writable	Client.call(Writable param, InetSocketAddress address) 已过时。 Use Client.call(Writable, ConnectionId) instead
Writable	Client.call(Writable param, InetSocketAddress addr, Class<?> protocol, UserGroupInformation ticket, int rpcTimeout) 已过时。 Use Client.call(Writable, ConnectionId) instead
Writable	Client.call(Writable param, InetSocketAddress addr, Class<?> protocol, UserGroupInformation ticket, int rpcTimeout, Configuration conf) Make a call, passing param, to the IPC server running at address which is servicing the protocol protocol, with the ticket credentials, rpcTimeout as timeout and conf as configuration for this connection, returning the value.
Writable	Client.call(Writable param, InetSocketAddress addr, UserGroupInformation ticket) 已过时。 Use Client.call(Writable, ConnectionId) instead
Writable	Server.call(Writable param, long receiveTime) 已过时。 Use Server.call(Class, Writable, long) instead

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

构造器和说明
Client(Class<? extends Writable> valueClass, Configuration conf) Construct an IPC client with the default SocketFactory
Client(Class<? extends Writable> valueClass, Configuration conf, SocketFactory factory) Construct an IPC client whose values are of the given Writable class.
Server(String bindAddress, int port, Class<? extends Writable> paramClass, int handlerCount, Configuration conf)
Server(String bindAddress, int port, Class<? extends Writable> paramClass, int handlerCount, Configuration conf, String serverName)
Server(String bindAddress, int port, Class<? extends Writable> paramClass, int handlerCount, Configuration conf, String serverName, SecretManager<? extends TokenIdentifier> secretManager) Constructs a server listening on the named port and address.

org.apache.hadoop.mapred中Writable的使用

org.apache.hadoop.mapred中Writable的子接口

限定符和类型	接口和说明
interface	InputSplit InputSplit represents the data to be processed by an individual Mapper.

实现Writable的org.apache.hadoop.mapred中的类

限定符和类型	类和说明
class	ClusterStatus Status information on the current state of the Map-Reduce cluster.
class	Counters A set of named counters.
static class	Counters.Counter A counter record, comprising its name and value.
class	Counters.Group Group of counters, comprising of counters from a particular counter Enum class.
class	FileSplit A section of an input file.
class	JobConf A map/reduce job configuration.
class	JobProfile A JobProfile is a MapReduce primitive.
class	JobQueueInfo Class that contains the information regarding the Job Queues which are maintained by the Hadoop Map/Reduce framework.
class	JobStatus Describes the current status of a job.
class	JvmTask
class	MapTaskCompletionEventsUpdate A class that represents the communication between the tasktracker and child tasks w.r.t the map task completion events.
class	MultiFileSplit 已过时。 Use CombineFileSplit instead
class	QueueAclsInfo Class to encapsulate Queue ACLs for a particular user.
class	Task Base class for tasks.
class	TaskCompletionEvent This is used to track task completion events on job tracker.
class	TaskReport A report on the state of a task.
class	TaskStatus Describes the current status of a task.
class	TaskTrackerStatus A TaskTrackerStatus is a MapReduce primitive.

类型参数类型为Writable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Writable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Writable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 Writable>	SequenceFileAsBinaryOutputFormat.getSequenceFileOutputValueClass(JobConf conf) Get the value class for the SequenceFile

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

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

限定符和类型	类和说明
class	ArrayListBackedIterator<X extends Writable> This class provides an implementation of ResetableIterator.
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	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	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	MultiFilterRecordReader<K extends WritableComparable,V extends Writable> Base class for Composite join returning values derived from multiple sources, but generally not tuples.
class	OverrideRecordReader<K extends WritableComparable,V extends Writable> Prefer the "rightmost" data source for this key.
interface	ResetableIterator<T extends Writable> This defines an interface to a stateful Iterator that can replay elements added to it directly.
static class	ResetableIterator.EMPTY<U extends Writable>
class	StreamBackedIterator<X extends Writable> This class provides an implementation of ResetableIterator.
class	WrappedRecordReader<K extends WritableComparable,U extends Writable> Proxy class for a RecordReader participating in the join framework.

实现Writable的org.apache.hadoop.mapred.join中的类

限定符和类型	类和说明
class	CompositeInputSplit This InputSplit contains a set of child InputSplits.
class	TupleWritable Writable type storing multiple Writables.

返回Writable的org.apache.hadoop.mapred.join中的方法

限定符和类型	方法和说明
Writable	TupleWritable.get(int i) Get ith Writable from Tuple.

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

限定符和类型	方法和说明
Iterator<Writable>	TupleWritable.iterator() Return an iterator over the elements in this tuple.

参数类型为Writable的org.apache.hadoop.mapred.join中的构造器

构造器和说明
TupleWritable(Writable[] vals) Initialize tuple with storage; unknown whether any of them contain "written" values.

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

实现Writable的org.apache.hadoop.mapred.lib中的类

限定符和类型	类和说明
class	CombineFileSplit A sub-collection of input files.

返回变量类型为Writable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 Writable>	MultipleOutputs.getNamedOutputValueClass(JobConf conf, String namedOutput) Returns the value class for a named output.

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

类型参数类型为Writable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.mapred.lib.db中Writable的使用

实现Writable的org.apache.hadoop.mapred.lib.db中的类

限定符和类型	类和说明
protected static class	DBInputFormat.DBInputSplit A InputSplit that spans a set of rows
static class	DBInputFormat.NullDBWritable A Class that does nothing, implementing DBWritable

org.apache.hadoop.mapreduce中Writable的使用

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

限定符和类型	类和说明
class	ClusterMetrics Status information on the current state of the Map-Reduce cluster.
class	Counter A named counter that tracks the progress of a map/reduce job.
class	CounterGroup A group of Counters that logically belong together.
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.db中Writable的使用

实现Writable的org.apache.hadoop.mapreduce.lib.db中的类

限定符和类型	类和说明
static class	DataDrivenDBInputFormat.DataDrivenDBInputSplit A InputSplit that spans a set of rows

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

返回变量类型为Writable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 Writable>	SequenceFileAsBinaryOutputFormat.getSequenceFileOutputValueClass(JobContext job) Get the value class for the SequenceFile

org.apache.hadoop.mapreduce.security.token中Writable的使用

实现Writable的org.apache.hadoop.mapreduce.security.token中的类

限定符和类型	类和说明
class	JobTokenIdentifier The token identifier for job token

org.apache.hadoop.mapreduce.security.token.delegation中Writable的使用

实现Writable的org.apache.hadoop.mapreduce.security.token.delegation中的类

限定符和类型	类和说明
class	DelegationTokenIdentifier A delegation token identifier that is specific to MapReduce.

org.apache.hadoop.mapreduce.split中Writable的使用

实现Writable的org.apache.hadoop.mapreduce.split中的类

限定符和类型	类和说明
static class	JobSplit.SplitMetaInfo This represents the meta information about the task split.

org.apache.hadoop.record中Writable的使用

实现Writable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.

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

实现Writable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.security中Writable的使用

实现Writable的org.apache.hadoop.security中的类

限定符和类型	类和说明
class	Credentials A class that provides the facilities of reading and writing secret keys and Tokens.

org.apache.hadoop.security.authorize中Writable的使用

实现Writable的org.apache.hadoop.security.authorize中的类

限定符和类型	类和说明
class	AccessControlList Class representing a configured access control list.

org.apache.hadoop.security.token中Writable的使用

实现Writable的org.apache.hadoop.security.token中的类

限定符和类型	类和说明
class	Token<T extends TokenIdentifier> The client-side form of the token.
class	TokenIdentifier An identifier that identifies a token, may contain public information about a token, including its kind (or type).

org.apache.hadoop.security.token.delegation中Writable的使用

实现Writable的org.apache.hadoop.security.token.delegation中的类

限定符和类型	类和说明
class	AbstractDelegationTokenIdentifier
class	DelegationKey Key used for generating and verifying delegation tokens

org.apache.hadoop.streaming.io中Writable的使用

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

限定符和类型	方法和说明
void	RawBytesInputWriter.writeKey(Writable key)
void	RawBytesInputWriter.writeValue(Writable value)

org.apache.hadoop.tools.rumen中Writable的使用

实现Writable的org.apache.hadoop.tools.rumen中的类

限定符和类型	类和说明
class	ResourceUsageMetrics Captures the resource usage metrics.

org.apache.hadoop.typedbytes中Writable的使用

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

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

返回Writable的org.apache.hadoop.typedbytes中的方法

限定符和类型	方法和说明
Writable	TypedBytesWritableInput.read()
Writable	TypedBytesWritableInput.readWritable()
Writable	TypedBytesWritableInput.readWritable(Writable writable)

返回变量类型为Writable的类型的org.apache.hadoop.typedbytes中的方法

限定符和类型	方法和说明
Class<? extends Writable>	TypedBytesWritableInput.readType()

参数类型为Writable的org.apache.hadoop.typedbytes中的方法

限定符和类型	方法和说明
Writable	TypedBytesWritableInput.readWritable(Writable writable)
void	TypedBytesWritableOutput.write(Writable w)
void	TypedBytesWritableOutput.writeWritable(Writable w)

org.apache.hadoop.util中Writable的使用

参数类型为Writable的org.apache.hadoop.util中的方法

限定符和类型	方法和说明
static void	ReflectionUtils.cloneWritableInto(Writable dst, Writable src) 已过时。

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

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

限定符和类型	类和说明
class	BloomFilter Implements a Bloom filter, as defined by Bloom in 1970.
class	CountingBloomFilter Implements a counting Bloom filter, as defined by Fan et al. in a ToN 2000 paper.
class	DynamicBloomFilter Implements a dynamic Bloom filter, as defined in the INFOCOM 2006 paper.
class	Filter Defines the general behavior of a filter.
class	Key The general behavior of a key that must be stored in a filter.
class	RetouchedBloomFilter Implements a retouched Bloom filter, as defined in the CoNEXT 2006 paper.