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

Packages that use Writable
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.ipc Tools to help define network clients and servers. 
org.apache.hadoop.mapred A system for scalable, fault-tolerant, distributed computation over large data collections. 
org.apache.hadoop.mapred.lib Library of generally useful mappers, reducers, and partitioners. 
 

Uses of Writable in org.apache.hadoop.examples
 

Methods in org.apache.hadoop.examples with parameters of type Writable
 void RandomWriter.Map.map(WritableComparable key, Writable value, OutputCollector output, Reporter reporter)
          Given an output filename, write a bunch of random records to it.
 void WordCount.MapClass.map(WritableComparable key, Writable value, OutputCollector output, Reporter reporter)
           
 

Uses of Writable in org.apache.hadoop.io
 

Subinterfaces of Writable in org.apache.hadoop.io
 interface WritableComparable
          An interface which extends both Writable and Comparable.
 

Classes in org.apache.hadoop.io that implement Writable
 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 CompressedWritable
          A base-class for Writables which store themselves compressed and lazily inflate on field access.
 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 ObjectWritable
          A polymorphic Writable that writes an instance with it's class name.
 class TwoDArrayWritable
          A Writable for 2D arrays containing a matrix of instances of a class.
 class UTF8
          A WritableComparable for strings that uses the UTF8 encoding.
 class VersionedWritable
          A base class for Writables that provides version checking.
 

Methods in org.apache.hadoop.io that return Writable
static Writable WritableUtils.clone(Writable orig, JobConf conf)
          Make a copy of a writable object using serialization to a buffer.
 Writable[][] TwoDArrayWritable.get()
           
 Writable[] ArrayWritable.get()
           
 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 WritableFactory.newInstance()
          Return a new instance.
static Writable WritableFactories.newInstance(Class c)
          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.
 

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, JobConf conf)
          Make a copy of a writable object using serialization to a buffer.
 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.
 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.
 void ArrayWritable.set(Writable[] values)
           
 void TwoDArrayWritable.set(Writable[][] values)
           
 

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.ipc
 

Methods in org.apache.hadoop.ipc that return Writable
 Writable RPC.Server.call(Writable param)
           
abstract  Writable Server.call(Writable param)
          Called for each call.
 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.
 

Methods in org.apache.hadoop.ipc with parameters of type Writable
 Writable RPC.Server.call(Writable param)
           
abstract  Writable Server.call(Writable param)
          Called for each call.
 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.
 

Uses of Writable in org.apache.hadoop.mapred
 

Classes in org.apache.hadoop.mapred that implement Writable
 class ClusterStatus
          Summarizes the size and current state of the cluster.
 class FileSplit
          A section of an input file.
 class TaskReport
          A report on the state of a task.
 

Methods in org.apache.hadoop.mapred that return Writable
static Writable MapFileOutputFormat.getEntry(MapFile.Reader[] readers, Partitioner partitioner, WritableComparable key, Writable value)
          Get an entry from output generated by this class.
 

Methods in org.apache.hadoop.mapred with parameters of type Writable
 void OutputCollector.collect(WritableComparable key, Writable value)
          Adds a key/value pair to the output.
static Writable MapFileOutputFormat.getEntry(MapFile.Reader[] readers, Partitioner partitioner, WritableComparable key, Writable value)
          Get an entry from output generated by this class.
 int Partitioner.getPartition(WritableComparable key, Writable value, int numPartitions)
          Returns the paritition number for a given entry given the total number of partitions.
 void Mapper.map(WritableComparable key, Writable value, OutputCollector output, Reporter reporter)
          Maps a single input key/value pair into intermediate key/value pairs.
 boolean SequenceFileRecordReader.next(Writable key, Writable value)
           
 boolean RecordReader.next(Writable key, Writable value)
          Reads the next key/value pair.
 void RecordWriter.write(WritableComparable key, Writable value)
          Writes a key/value pair.
 

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

Methods in org.apache.hadoop.mapred.lib with parameters of type Writable
 int HashPartitioner.getPartition(WritableComparable key, Writable value, int numReduceTasks)
          Use Object.hashCode() to partition.
 void TokenCountMapper.map(WritableComparable key, Writable value, OutputCollector output, Reporter reporter)
           
 void RegexMapper.map(WritableComparable key, Writable value, OutputCollector output, Reporter reporter)
           
 void InverseMapper.map(WritableComparable key, Writable value, OutputCollector output, Reporter reporter)
          The inverse function.
 void IdentityMapper.map(WritableComparable key, Writable val, OutputCollector output, Reporter reporter)
          The identify function.
 



Copyright © 2006 The Apache Software Foundation