org.apache.xindice.core.indexer
Class LuceneIndexer

java.lang.Object
  org.apache.xindice.core.indexer.LuceneIndexer

All Implemented Interfaces:

Configurable, DBObject, Indexer, Named

public final class LuceneIndexer

extends Object

implements Indexer, DBObject

LuceneIndexer is used for maintaining full text indexes. It operates on documents instead of elements and allows to search for documents using native Lucene query. There can be only one LuceneIndexer per collection, however, it may have more than one IndexPattern.

Every IndexPattern corresponds to a Lucene document field. For every Xindice document, value of all matching elements will be indexed by a single Lucene document, allowing to search across the patterns.

Sample LuceneIndexer configuration:

 <index name='fulltext' class='org.apache.xindice.core.indexer.LuceneIndexer'
                        analyzer='org.apache.lucene.analysis.SimpleAnalyzer'>
   <pattern pattern='meta@title' alias='title'/>
   <pattern pattern='description' alias='text'/>
 </index>

To search over this sample index, one could issue a query "title:tutorial AND text:xml".

For more details about LuceneIndexer configuration please see documentation for setConfig(org.apache.xindice.util.Configuration)

Version:

$Revision: 586647 $, $Date: 2007-10-19 20:32:43 -0400 (Fri, 19 Oct 2007) $

Author:

Andy Armstrong

Field Summary

static String	DEFANALYZER
static String	KEYNAME

Fields inherited from interface org.apache.xindice.core.indexer.Indexer

STYLE_FULLTEXT, STYLE_NODENAME, STYLE_NODEVALUE

Constructor Summary

LuceneIndexer()

Method Summary

boolean	close() close closes the DBObject
boolean	create() Creates necessary resources.
boolean	drop() drop instructs the DBObjectimplementation to remove itself from existence.
boolean	exists() exists returns whether or not a physical representation of this DBObject actually exists.
void	flush() flush forcefully flushes any unwritten buffers to disk.
org.apache.lucene.analysis.Analyzer	getAnalyzer()
Configuration	getConfig() getConfig retrieves the configuration information for the Configurable object instance.
IndexerEventHandler	getIndexerEventHandler() Creates new instance of a handler to listen to indexer events.
String	getIndexStyle() getIndexStyle returns the Index style.
String	getName() getName retrieves the contextually important name of the object
String	getPatternAlias(IndexPattern pattern) Return alias for the given pattern.
IndexPattern[]	getPatterns() Returns this Indexer's patterns.
boolean	isOpened() isOpened returns whether or not the DBObject is opened for business.
boolean	open() open opens the DBObject
IndexMatch[]	queryMatches(IndexQuery query) queryMatches retrieves a set of IndexMatch instances that match the supplied query.
IndexMatch[]	queryMatches(org.apache.lucene.search.Query query) Same as Indexer.queryMatches(IndexQuery), but accepts compiled Lucene query as parameter.
void	setCollection(Collection collection) setCollection tells the Indexer who its parent is.
void	setConfig(Configuration config) Configures LuceneIndexer instance.

Methods inherited from class java.lang.Object

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

Field Detail

KEYNAME

public static final String KEYNAME

See Also:

Constant Field Values

DEFANALYZER

public static final String DEFANALYZER

See Also:

Constant Field Values

Constructor Detail

LuceneIndexer

public LuceneIndexer()

Method Detail

getIndexStyle

public String getIndexStyle()

Description copied from interface: Indexer

getIndexStyle returns the Index style. Different query languages will need to draw from different indexing styles. For example, A query that is written in quilt will require XPath indexing.

Specified by:

getIndexStyle in interface Indexer

Returns:

The index style

getPatterns

public IndexPattern[] getPatterns()

Returns this Indexer's patterns. LuceneIndexer may have more than one pattern.

Specified by:

getPatterns in interface Indexer

Returns:

Indexer's patterns

getPatternAlias

public String getPatternAlias(IndexPattern pattern)

Return alias for the given pattern. If this exact pattern is not indexed, method will look for matching indexed pattern.

Parameters:

pattern - IndexPattern

Returns:

Alias for the closest matching pattern or null, if there is none

setConfig

public void setConfig(Configuration config)
               throws XindiceException

Configures LuceneIndexer instance.

index

Top Indexer configuration element. Can have one or more pattern child elements. Its attributes:

• name - Indexer name. Required.
• class - Indexer class. Required. org.apache.xindice.core.indexer.LuceneIndexer for full text index.
• analyzer - Analyzer to use for indexing. Optional, org.apache.lucene.analysis.SimpleAnalyzer by default.

pattern

Child element. Indexer must have at least one pattern. Its attributes:

• pattern - IndexPattern. For acceptable formats, see Indexer.getPatterns()
• alias - Name of the field to store/search values for that pattern.

default

Child element. Optional. Its attributes:

alias - Indicates the pattern alias that will be used as the default field for search. If omitted, search query has to include field name for all terms, there will be no default.

Specified by:

setConfig in interface Configurable

Parameters:

config - Configuration to apply

Throws:

XindiceException - Configuration does not have required information, Analyzer could not have been instantiated.

getConfig

public Configuration getConfig()

Description copied from interface: Configurable

getConfig retrieves the configuration information for the Configurable object instance.

Specified by:

getConfig in interface Configurable

Returns:

The configuration Node

exists

public boolean exists()

Description copied from interface: DBObject

exists returns whether or not a physical representation of this DBObject actually exists. In the case of a HashFiler, this would check for the file, and in the case of an FTPFiler, it might perform a connection check.

Specified by:

exists in interface DBObject

Returns:

Whether or not the physical resource exists

create

public boolean create()
               throws DBException

Creates necessary resources.

Specified by:

create in interface DBObject

Returns:

true, if successful

Throws:

DBException - The was low-level IOException that prevented index from creating resources.

DuplicateIndexException - Parent collection already has full text index

open

public boolean open()
             throws DBException

Description copied from interface: DBObject

open opens the DBObject

Specified by:

open in interface DBObject

Returns:

Whether or not the DBObject was opened

Throws:

DBException - if operation failed

isOpened

public boolean isOpened()

Description copied from interface: DBObject

isOpened returns whether or not the DBObject is opened for business.

Specified by:

isOpened in interface DBObject

Returns:

The open status of the DBObject

close

public boolean close()
              throws DBException

Description copied from interface: DBObject

close closes the DBObject

Specified by:

close in interface DBObject

Returns:

Whether or not the DBObject was closed

Throws:

DBException - if operation failed

drop

public boolean drop()
             throws DBException

Description copied from interface: DBObject

drop instructs the DBObjectimplementation to remove itself from existence. The DBObject's parent is responsible for removing any references to the DBObject in its own context.

Specified by:

drop in interface DBObject

Returns:

Whether or not the DBObject was dropped

Throws:

DBException - if operation failed

getName

public String getName()

Description copied from interface: Named

getName retrieves the contextually important name of the object

Specified by:

getName in interface Named

Returns:

The object's name

setCollection

public void setCollection(Collection collection)

Description copied from interface: Indexer

setCollection tells the Indexer who its parent is.

Specified by:

setCollection in interface Indexer

Parameters:

collection - The owner Collection

getAnalyzer

public org.apache.lucene.analysis.Analyzer getAnalyzer()

flush

public void flush()
           throws DBException

Description copied from interface: Indexer

flush forcefully flushes any unwritten buffers to disk.

Specified by:

flush in interface Indexer

Throws:

DBException

getIndexerEventHandler

public IndexerEventHandler getIndexerEventHandler()

Creates new instance of a handler to listen to indexer events. For every document that being added there will be a separate handler that will assemble all relevant values in a single Lucene document.

Specified by:

getIndexerEventHandler in interface Indexer

Returns:

new instance of IndexerEventHandler

See Also:

IndexerEventHandler

queryMatches

public IndexMatch[] queryMatches(IndexQuery query)
                          throws DBException

Description copied from interface: Indexer

queryMatches retrieves a set of IndexMatch instances that match the supplied query. The matches are then used by the QueryEngine in co-sequential processing. If this indexer doesn't support the passed value, it should return 'null'. If no matches are found, it should return an empty set. queryMatches will typically be used in XPath processing.

Specified by:

queryMatches in interface Indexer

Parameters:

query - The IndexQuery to use

Returns:

The resulting matches

Throws:

DBException

queryMatches

public IndexMatch[] queryMatches(org.apache.lucene.search.Query query)
                          throws DBException

Same as Indexer.queryMatches(IndexQuery), but accepts compiled Lucene query as parameter.

Parameters:

query - Compiled Lucene query.

Returns:

The resulting matches

Throws:

DBException - if IOException prevented indexer from executing the query.