com.google.enterprise.connector.util.diffing

Class DiffingConnectorDocumentList

java.lang.Object

com.google.enterprise.connector.util.diffing.DiffingConnectorDocumentList

All Implemented Interfaces:

DocumentList

public class DiffingConnectorDocumentList
extends java.lang.Object
implements DocumentList

An implementation of DocumentList for the DiffingConnector.

Since:

2.8

Constructor Summary

Constructors

Constructor and Description
DiffingConnectorDocumentList(CheckpointAndChangeQueue queue, java.lang.String checkpoint) Creates a document list that returns a batch of documents from the provided CheckpointAndChangeQueue.

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

DiffingConnectorDocumentList

public DiffingConnectorDocumentList(CheckpointAndChangeQueue queue,
                                    java.lang.String checkpoint)
                             throws java.io.IOException

Creates a document list that returns a batch of documents from the provided CheckpointAndChangeQueue.

Parameters:

queue - a CheckpointAndChangeQueue containing document changes

checkpoint - point into the change queue after which to start returning documents

Throws:

java.io.IOException - if persisting fails

Method Detail

checkpoint

public java.lang.String checkpoint()

Description copied from interface: DocumentList

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:

a non-null String that can be supplied subsequently to TraversalManager.resumeTraversal(String)

nextDocument

public Document nextDocument()
                      throws RepositoryException

Description copied from interface: DocumentList

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

Specified by:

nextDocument in interface DocumentList

Returns:

the new current document if there is one; null otherwise

Throws:

RepositoryException - if a repository access error occurs The Connector Manager will stop processing the DocumentList, call DocumentList.checkpoint(), and wait a short period of time before resuming traversal.

RepositoryDocumentException - if this specific document has unrecoverable errors. This document will be skipped, and nextDocument() or DocumentList.checkpoint() may be subsequently called.