org.carrot2.source.lucene
Class LuceneDocumentSource

java.lang.Object
  org.carrot2.core.ProcessingComponentBase
      org.carrot2.source.lucene.LuceneDocumentSource

All Implemented Interfaces:

IDocumentSource, IProcessingComponent

public final class LuceneDocumentSource
extends ProcessingComponentBase
implements IDocumentSource

A IDocumentSource fetching Documents from a local Apache Lucene index. The index should be binary-compatible with the Lucene version actually imported by this plugin.

Field Summary

org.apache.lucene.analysis.Analyzer	analyzer Analyzer used at indexing time.
org.apache.lucene.store.Directory	directory Search index Directory.
Collection<Document>	documents
IFieldMapper	fieldMapper IFieldMapper provides the link between Carrot2 Document fields and Lucene index fields.
boolean	keepLuceneDocuments Keeps references to Lucene document instances in Carrot2 documents.
static String	LUCENE_DOCUMENT_FIELD Carrot2 Document field that stores the original Lucene document instance.
Object	query A pre-parsed Query object or a String parsed using the built-in QueryParser over a set of search fields returned from the fieldMapper.
int	results
long	resultsTotal

Constructor Summary

LuceneDocumentSource()

Method Summary

protected SearchEngineResponse	fetchSearchResponse() Fetch search engine response.
void	init(IControllerContext context) Invoked after component's attributes marked with Init and Input annotations have been bound, but before calls to any other methods of this component.
void	process() Performs the processing required to fulfill the request.

Methods inherited from class org.carrot2.core.ProcessingComponentBase

afterProcessing, beforeProcessing, dispose, getContext, getSharedExecutor

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.carrot2.core.IProcessingComponent

afterProcessing, beforeProcessing, dispose

Field Detail

results

public int results

resultsTotal

public long resultsTotal

documents

public Collection<Document> documents

directory

public org.apache.lucene.store.Directory directory

Search index Directory. Must be unlocked for reading.

Attribute label:

Index directory

Attribute level:

Basic

Attribute group:

Index properties

analyzer

public org.apache.lucene.analysis.Analyzer analyzer

Analyzer used at indexing time. The same analyzer should be used for querying.

Attribute label:

Analyzer

Attribute level:

Medium

Attribute group:

Index properties

fieldMapper

public IFieldMapper fieldMapper

IFieldMapper provides the link between Carrot2 Document fields and Lucene index fields.

Attribute label:

Field mapper

Attribute level:

Advanced

Attribute group:

Index field mapping

query

public Object query

A pre-parsed Query object or a String parsed using the built-in QueryParser over a set of search fields returned from the fieldMapper.

Attribute label:

Query

Attribute level:

Basic

Attribute group:

Search query

keepLuceneDocuments

public boolean keepLuceneDocuments

Keeps references to Lucene document instances in Carrot2 documents. Please bear in mind two limitations:

• Lucene documents will not be serialized to XML/JSON. Therefore, they can only be accessed when invoking clustering through Carrot2 Java API. To pass some of the fields of Lucene documents to Carrot2 XML/JSON output, implement a custom IFieldMapper that will store those fields as regular Carrot2 fields.
• Increased memory usage when using a Controller configured to cache the output from LuceneDocumentSource.

Attribute label:

Keep Lucene documents

Attribute level:

Advanced

Attribute group:

Results

LUCENE_DOCUMENT_FIELD

public static final String LUCENE_DOCUMENT_FIELD

Carrot2 Document field that stores the original Lucene document instance. Keeping of Lucene document instances is disabled by default. Enable it using the keepLuceneDocuments attribute.

See Also:

Constant Field Values

Constructor Detail

LuceneDocumentSource

public LuceneDocumentSource()

Method Detail

init

public void init(IControllerContext context)

Description copied from interface: IProcessingComponent

Invoked after component's attributes marked with Init and Input annotations have been bound, but before calls to any other methods of this component. After a call to this method completes without an exception, attributes marked with Init Output will be collected. In this method, components should perform initializations based on the initialization-time attributes. This method is called once in the life time of a processing component instance.

Specified by:

init in interface IProcessingComponent

Overrides:

init in class ProcessingComponentBase

Parameters:

context - An instance of IControllerContext of the controller to which this component instance will be bound.

process

public void process()
             throws ProcessingException

Description copied from interface: IProcessingComponent

Performs the processing required to fulfill the request. This method is called once per request.

Specified by:

process in interface IProcessingComponent

Overrides:

process in class ProcessingComponentBase

Throws:

ProcessingException - when processing failed. If thrown, the IProcessingComponent.afterProcessing() method will be called and the component will be ready to accept further requests or to be disposed of. Finally, the exception will be rethrown from the controller method that caused the component to perform processing.

fetchSearchResponse

protected SearchEngineResponse fetchSearchResponse()
                                            throws Exception

Fetch search engine response.

Throws:

Exception