com.google.enterprise.connector.util

Class EmptyDocumentList

java.lang.Object

com.google.enterprise.connector.util.EmptyDocumentList

All Implemented Interfaces:

DocumentList

public class EmptyDocumentList
extends java.lang.Object
implements DocumentList

An empty document list that provides a new checkpoint.

Since:

3.0

Constructor Summary

Constructors

Constructor and Description
EmptyDocumentList(java.lang.String checkpoint) Constructs an empty document list with the given checkpoint.

Method Summary

Modifier and Type	Method and Description
java.lang.String	checkpoint() Provides a checkpoint that can be used to control traversal.
Document	nextDocument() Returns the next Document in this document list, if there is one.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

EmptyDocumentList

public EmptyDocumentList(java.lang.String checkpoint)

Constructs an empty document list with the given checkpoint.

Parameters:

checkpoint - the checkpoint for this document list

Method Detail

nextDocument

public Document nextDocument()

Returns the next Document in this document list, if there is one.

Specified by:

nextDocument in interface DocumentList

Returns:

null, always, to indicate that this document list contains no documents.

checkpoint

public java.lang.String checkpoint()

Provides a checkpoint that can be used to control traversal. The implementor should provide a string that can be used by the framework to resume traversal starting just after this document. The framework will typically call this method on the last document it has chosen to process (for whatever reason: scheduling, completion of all documents currently available, etc.) It will persist this string, so that it can be recovered after a crash if necessary. When it chooses to restart traversal, it will supply this string in a call to TraversalManager.resumeTraversal(String).

If null is returned, then no new checkpoint will be saved, and the existing checkpoint will be supplied to TraversalManager.startTraversal() or TraversalManager.resumeTraversal(String), in effect, restarting the traversal from the last saved checkpoint.

Specified by:

checkpoint in interface DocumentList

Returns:

the checkpoint for this document list