cascading.tap.local
Class StdInTap

java.lang.Object
  cascading.tap.Tap<Config,Input,Void>
      cascading.tap.SourceTap<Properties,InputStream>
          cascading.tap.local.StdInTap

All Implemented Interfaces:

FlowElement, Serializable

public class StdInTap
extends SourceTap<Properties,InputStream>

Class StdInTap provides a local mode tap for reading data from the stdin stream.

See Also:

Serialized Form

Constructor Summary

StdInTap(Scheme<Properties,InputStream,?,?,?> scheme)

Method Summary

String	getIdentifier() Method getIdentifier returns a String representing the resource this Tap instance represents.
long	getModifiedTime(Properties conf) Method getModifiedTime returns the date this resource was last modified.
TupleEntryIterator	openForRead(FlowProcess<Properties> flowProcess, InputStream inputStream) Method openForRead opens the resource represented by this Tap instance.
boolean	resourceExists(Properties conf) Method resourceExists returns true if the path represented by this instance exists.

Methods inherited from class cascading.tap.SourceTap

commitResource, createResource, deleteResource, getSinkFields, isSink, openForWrite, rollbackResource, sinkConfInit

Methods inherited from class cascading.tap.Tap

equals, flowConfInit, getConfigDef, getFullIdentifier, getScheme, getSinkMode, getSourceFields, getStepConfigDef, getTrace, hasConfigDef, hashCode, hasStepConfigDef, id, isEquivalentTo, isKeep, isReplace, isSource, isTemporary, isUpdate, openForRead, openForWrite, outgoingScopeFor, presentSinkFields, presentSourceFields, resolveFields, resolveIncomingOperationFields, retrieveSinkFields, retrieveSourceFields, setScheme, sourceConfInit, taps, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

StdInTap

public StdInTap(Scheme<Properties,InputStream,?,?,?> scheme)

Method Detail

getIdentifier

public String getIdentifier()

Description copied from class: Tap

Method getIdentifier returns a String representing the resource this Tap instance represents.

Often, if the tap accesses a filesystem, the identifier is nothing more than the path to the file or directory. In other cases it may be a an URL or URI representing a connection string or remote resource.

Any two Tap instances having the same value for the identifier are considered equal.

Specified by:

getIdentifier in class Tap<Properties,InputStream,Void>

Returns:

String

openForRead

public TupleEntryIterator openForRead(FlowProcess<Properties> flowProcess,
                                      InputStream inputStream)
                               throws IOException

Description copied from class: Tap

Method openForRead opens the resource represented by this Tap instance.

input value may be null, if so, sub-classes must inquire with the underlying Scheme via Scheme.sourceConfInit(cascading.flow.FlowProcess, Tap, Object) to get the proper input type and instantiate it before calling super.openForRead().

Note the returned iterator will return the same instance of TupleEntry on every call, thus a copy must be made of either the TupleEntry or the underlying Tuple instance if they are to be stored in a Collection.

Specified by:

openForRead in class Tap<Properties,InputStream,Void>

Returns:

TupleEntryIterator @throws java.io.IOException when the resource cannot be opened

Throws:

IOException

resourceExists

public boolean resourceExists(Properties conf)
                       throws IOException

Description copied from class: Tap

Method resourceExists returns true if the path represented by this instance exists.

Specified by:

resourceExists in class Tap<Properties,InputStream,Void>

Parameters:

conf - of type JobConf

Returns:

true if the underlying resource already exists

Throws:

IOException - when the status cannot be determined

getModifiedTime

public long getModifiedTime(Properties conf)
                     throws IOException

Description copied from class: Tap

Method getModifiedTime returns the date this resource was last modified.

Specified by:

getModifiedTime in class Tap<Properties,InputStream,Void>

Parameters:

conf - of type Config

Returns:

The date this resource was last modified.

Throws:

IOException