cascading.tap
Class SourceTap

java.lang.Object
  cascading.tap.Tap
      cascading.tap.SourceTap

All Implemented Interfaces:

FlowElement, Serializable

Direct Known Subclasses:

MultiSourceTap

public abstract class SourceTap
extends Tap

Class SourceTap is the base class for MultiSourceTap. Some Tap instances may only be sources (as opposed to being a sink). These types should subclass SourceTap for convenience.

See Also:

Serialized Form

Constructor Summary

protected	SourceTap()
protected	SourceTap(Scheme scheme)

Method Summary

boolean	deletePath(JobConf conf) Method deletePath deletes the resource represented by this instance.
Fields	getSinkFields() Method getSinkFields returns the sinkFields of this Tap object.
boolean	isSink() Method isSink returns true if this Tap instance can be used as a sink.
boolean	makeDirs(JobConf conf) Method makeDirs makes all the directories this Tap instance represents.
TupleEntryIterator	openForRead(JobConf conf) Method openForRead opens the resource represented by this Tap instance.
TupleEntryCollector	openForWrite(JobConf conf) Method openForWrite opens the resource represented by this Tap instance.
void	sink(TupleEntry tupleEntry, OutputCollector outputCollector) Method sink emits the sink value(s) to the OutputCollector

Methods inherited from class cascading.tap.Tap

equals, flowInit, getIdentifier, getPath, getPathModified, getQualifiedPath, getScheme, getSinkMode, getSourceFields, hashCode, isAppend, isEquivalentTo, isKeep, isReplace, isSource, isUpdate, isWriteDirect, outgoingScopeFor, pathExists, resolveFields, resolveIncomingOperationFields, setScheme, setWriteDirect, sinkInit, source, sourceInit, taps

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SourceTap

protected SourceTap()

SourceTap

protected SourceTap(Scheme scheme)

Method Detail

getSinkFields

public Fields getSinkFields()

Description copied from class: Tap

Method getSinkFields returns the sinkFields of this Tap object.

Overrides:

getSinkFields in class Tap

Returns:

the sinkFields (type Fields) of this Tap object.

sink

public void sink(TupleEntry tupleEntry,
                 OutputCollector outputCollector)
          throws IOException

Description copied from class: Tap

Method sink emits the sink value(s) to the OutputCollector

Overrides:

sink in class Tap

Parameters:

tupleEntry - of type TupleEntry

outputCollector - of type OutputCollector

Throws:

IOException - when the resource cannot be written to

isSink

public final boolean isSink()

Description copied from class: Tap

Method isSink returns true if this Tap instance can be used as a sink.

Overrides:

isSink in class Tap

Returns:

boolean

deletePath

public boolean deletePath(JobConf conf)
                   throws IOException

Description copied from class: Tap

Method deletePath deletes the resource represented by this instance.

Specified by:

deletePath in class Tap

Parameters:

conf - of type JobConf

Returns:

boolean

Throws:

IOException - when the resource cannot be deleted

See Also:

Tap.deletePath(JobConf)

makeDirs

public boolean makeDirs(JobConf conf)
                 throws IOException

Description copied from class: Tap

Method makeDirs makes all the directories this Tap instance represents.

Specified by:

makeDirs in class Tap

Parameters:

conf - of type JobConf

Returns:

boolean

Throws:

IOException - when there is an error making directories

See Also:

Tap.makeDirs(JobConf)

openForRead

public TupleEntryIterator openForRead(JobConf conf)
                               throws IOException

Description copied from class: Tap

Method openForRead opens the resource represented by this Tap instance.

Specified by:

openForRead in class Tap

Parameters:

conf - of type JobConf

Returns:

TupleEntryIterator

Throws:

IOException - when the resource cannot be opened

openForWrite

public TupleEntryCollector openForWrite(JobConf conf)
                                 throws IOException

Description copied from class: Tap

Method openForWrite opens the resource represented by this Tap instance.

Specified by:

openForWrite in class Tap

Parameters:

conf - of type JobConf

Returns:

TupleEntryCollector

Throws:

IOException - when