Uses of Interface
org.apache.hadoop.io.Writable

Packages that use Writable

org.apache.hadoop.contrib.index.example
org.apache.hadoop.contrib.index.mapred
org.apache.hadoop.contrib.utils.join
org.apache.hadoop.dfs	A distributed implementation of FileSystem.
org.apache.hadoop.examples	Hadoop example code.
org.apache.hadoop.fs	An abstract file system API.
org.apache.hadoop.fs.permission
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.aggregate	Classes for performing various counting and aggregations.
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

Uses of Writable in org.apache.hadoop.contrib.index.example

Classes in org.apache.hadoop.contrib.index.example that implement Writable

class

LineDocTextAndOp This class represents an operation.

Uses of Writable in org.apache.hadoop.contrib.index.mapred

Classes in org.apache.hadoop.contrib.index.mapred with type parameters of type Writable

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.

Classes in org.apache.hadoop.contrib.index.mapred that implement Writable

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.

Methods in org.apache.hadoop.contrib.index.mapred that return types with arguments of type Writable

static Class<? extends Writable>	IndexUpdateMapper.getMapOutputValueClass() Get the map output value class.
static Class<? extends Writable>	IndexUpdateReducer.getOutputValueClass() Get the reduce output value class.

Uses of Writable in org.apache.hadoop.contrib.utils.join

Classes in org.apache.hadoop.contrib.utils.join that implement Writable

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.

Methods in org.apache.hadoop.contrib.utils.join that return Writable

abstract Writable

TaggedMapOutput.getData()

Uses of Writable in org.apache.hadoop.dfs

Classes in org.apache.hadoop.dfs that implement Writable

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.
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.
class	LocatedBlocks Collection of blocks with their locations and the file length.
class	UpgradeStatusReport Base upgrade upgradeStatus class.

Uses of Writable in org.apache.hadoop.examples

Classes in org.apache.hadoop.examples that implement Writable

static class

MultiFileWordCount.WordOffset This record keeps <filename,offset> pairs.

Methods in org.apache.hadoop.examples with parameters of type Writable

void	PiEstimator.PiMapper.map(LongWritable key, Writable val, OutputCollector<LongWritable,LongWritable> out, Reporter reporter) Map method.

Method parameters in org.apache.hadoop.examples with type arguments of type Writable

void	PiEstimator.PiReducer.reduce(LongWritable key, Iterator<LongWritable> values, OutputCollector<WritableComparable,Writable> output, Reporter reporter) Reduce method.

Uses of Writable in org.apache.hadoop.fs

Classes in org.apache.hadoop.fs that implement Writable

class	BlockLocation
class	ContentSummary Store the summary of a content (a directory or a file).
class	FileStatus Interface that represents the client side information for a file.

Uses of Writable in org.apache.hadoop.fs.permission

Classes in org.apache.hadoop.fs.permission that implement Writable

class	FsPermission A class for file/directory permissions.
class	PermissionStatus Store permission related information.

Uses of Writable in org.apache.hadoop.io

Subinterfaces of Writable in org.apache.hadoop.io

interface

WritableComparable<T> A Writable which is also Comparable.

Classes in org.apache.hadoop.io that implement Writable

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 Deprecated. 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.

Methods in org.apache.hadoop.io that return Writable

static Writable	WritableUtils.clone(Writable orig, Configuration conf) Make a copy of a writable object using serialization to a buffer.
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	WritableFactory.newInstance() Return a new instance.
static Writable	WritableFactories.newInstance(Class c) Create a new instance of a class with a defined factory.
static Writable	WritableFactories.newInstance(Class 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)

Methods in org.apache.hadoop.io that return types with arguments of type Writable

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()

Methods in org.apache.hadoop.io with parameters of type Writable

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	SequenceFile.Writer.append(Writable key, Writable val) Append a key/value pair.
static Writable	WritableUtils.clone(Writable orig, Configuration conf) Make a copy of a writable object using serialization to a buffer.
static void	WritableUtils.cloneInto(Writable dst, Writable src) Make a copy of the writable object using serialiation to a buffer
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.
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'.
Writable	ArrayFile.Reader.next(Writable value) Read and return the next value in the file.
boolean	SequenceFile.Reader.next(Writable key) Read the next key in the file into key, skipping its value.
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)

Method parameters in org.apache.hadoop.io with type arguments of type Writable

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)

Constructors in org.apache.hadoop.io with parameters of type Writable

ArrayWritable(Class valueClass, Writable[] values)

TwoDArrayWritable(Class valueClass, Writable[][] values)

Uses of Writable in org.apache.hadoop.io.serializer

Methods in org.apache.hadoop.io.serializer that return types with arguments of type Writable

Deserializer<Writable>	WritableSerialization.getDeserializer(Class<Writable> c)
Serializer<Writable>	WritableSerialization.getSerializer(Class<Writable> c)

Method parameters in org.apache.hadoop.io.serializer with type arguments of type Writable

Deserializer<Writable>	WritableSerialization.getDeserializer(Class<Writable> c)
Serializer<Writable>	WritableSerialization.getSerializer(Class<Writable> c)

Uses of Writable in org.apache.hadoop.ipc

Methods in org.apache.hadoop.ipc that return Writable

Writable[]	Client.call(Writable[] params, InetSocketAddress[] addresses) Makes a set of calls in parallel.
Writable	Client.call(Writable param, InetSocketAddress address) Make a call, passing param, to the IPC server running at address, returning the value.
Writable	Client.call(Writable param, InetSocketAddress addr, UserGroupInformation ticket)
abstract Writable	Server.call(Writable param, long receiveTime) Called for each call.
Writable	RPC.Server.call(Writable param, long receivedTime)

Methods in org.apache.hadoop.ipc with parameters of type Writable

Writable[]	Client.call(Writable[] params, InetSocketAddress[] addresses) Makes a set of calls in parallel.
Writable	Client.call(Writable param, InetSocketAddress address) Make a call, passing param, to the IPC server running at address, returning the value.
Writable	Client.call(Writable param, InetSocketAddress addr, UserGroupInformation ticket)
abstract Writable	Server.call(Writable param, long receiveTime) Called for each call.
Writable	RPC.Server.call(Writable param, long receivedTime)

Uses of Writable in org.apache.hadoop.mapred

Subinterfaces of Writable in org.apache.hadoop.mapred

interface

InputSplit InputSplit represents the data to be processed by an individual Mapper.

Classes in org.apache.hadoop.mapred that implement Writable

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.
static class	Counters.Group Group of counters, comprising of counters from a particular counter Enum class.
class	FileSplit A section of an input file.
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	JobProfile A JobProfile is a MapReduce primitive.
class	JobStatus Describes the current status of a job.
class	MultiFileSplit A sub-collection of input files.
class	TaskAttemptID TaskAttemptID represents the immutable and unique identifier for a task attempt.
class	TaskCompletionEvent This is used to track task completion events on job tracker.
class	TaskID TaskID represents the immutable and unique identifier for a Map or Reduce Task.
class	TaskReport A report on the state of a task.

Methods in org.apache.hadoop.mapred with type parameters of type Writable

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.

Methods in org.apache.hadoop.mapred that return Writable

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.

Methods in org.apache.hadoop.mapred that return types with arguments of type Writable

RecordWriter<WritableComparable,Writable>

MapFileOutputFormat.getRecordWriter(FileSystem ignored, JobConf job, String name, Progressable progress)

Uses of Writable in org.apache.hadoop.mapred.join

Classes in org.apache.hadoop.mapred.join with type parameters of type Writable

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.

Classes in org.apache.hadoop.mapred.join that implement Writable

class	CompositeInputSplit This InputSplit contains a set of child InputSplits.
class	TupleWritable Writable type storing multiple Writables.

Methods in org.apache.hadoop.mapred.join that return Writable

Writable

TupleWritable.get(int i) Get ith Writable from Tuple.

Methods in org.apache.hadoop.mapred.join that return types with arguments of type Writable

Iterator<Writable>

TupleWritable.iterator() Return an iterator over the elements in this tuple.

Constructors in org.apache.hadoop.mapred.join with parameters of type Writable

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

Uses of Writable in org.apache.hadoop.mapred.lib.aggregate

Classes in org.apache.hadoop.mapred.lib.aggregate with type parameters of type Writable

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.

Uses of Writable in org.apache.hadoop.record

Classes in org.apache.hadoop.record that implement Writable

class

Record Abstract class that is extended by generated classes.

Uses of Writable in org.apache.hadoop.record.meta

Classes in org.apache.hadoop.record.meta that implement Writable

class

RecordTypeInfo A record's Type Information object which can read/write itself.

Uses of Writable in org.apache.hadoop.security

Classes in org.apache.hadoop.security that implement Writable

class	UnixUserGroupInformation An implementation of UserGroupInformation in the Unix system
class	UserGroupInformation A Writable abstract class for storing user and groups information.