org.carrot2.source.lucene

Class LuceneDocumentSource

java.lang.Object

org.carrot2.core.ProcessingComponentBase

org.carrot2.source.lucene.LuceneDocumentSource

All Implemented Interfaces:

IDocumentSource, IProcessingComponent

@Bindable(prefix="LuceneDocumentSource",
          inherit=CommonAttributes.class)
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

Fields

Modifier and Type	Field and Description
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.
protected static String	INDEX_PROPERTIES
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 classic QueryParser over a set of search fields returned from the fieldMapper.
int	results
long	resultsTotal

Constructor Summary

Constructors

Constructor and Description
LuceneDocumentSource()

Method Summary

Methods

Modifier and Type	Method and Description
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

INDEX_PROPERTIES

protected static final String INDEX_PROPERTIES

See Also:

Constant Field Values

results

@Processing
@Input
@Attribute(key="results",
           inherit=true)
@IntRange(min=1)
public int results

resultsTotal

@Processing
@Output
@Attribute(key="results-total",
           inherit=true)
public long resultsTotal

documents

@Processing
@Output
@Attribute(key="documents",
           inherit=true)
@Internal
public Collection<Document> documents

directory

@Input
@Attribute
@Processing
@Required
@Internal(configuration=true)
@Label(value="Index directory")
@Level(value=BASIC)
@Group(value="Index properties")
public org.apache.lucene.store.Directory directory

Search index Directory. Must be unlocked for reading.

analyzer

@Input
@Processing
@Required
@Attribute
@Internal(configuration=false)
@Label(value="Analyzer")
@Level(value=MEDIUM)
@Group(value="Index properties")
public org.apache.lucene.analysis.Analyzer analyzer

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

fieldMapper

@Input
@Processing
@Required
@Attribute
@Internal
@Label(value="Field mapper")
@Level(value=ADVANCED)
@Group(value="Index field mapping")
public IFieldMapper fieldMapper

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

query

@Input
@Processing
@Attribute(key="query",
           inherit=false)
@Required
@Label(value="Query")
@Level(value=BASIC)
@Group(value="Search query")
public Object query

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

keepLuceneDocuments

@Input
@Processing
@Attribute
@Internal
@Label(value="Keep Lucene documents")
@Level(value=ADVANCED)
@Group(value="Search result information")
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.

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