net.sf.mmm.search.engine.impl.lucene

Class LuceneSearchEngine

java.lang.Object

net.sf.mmm.util.component.base.AbstractLoggableObject

net.sf.mmm.search.engine.base.AbstractSearchEngine

net.sf.mmm.search.engine.impl.lucene.LuceneSearchEngine

All Implemented Interfaces:

Closeable, AutoCloseable, ManagedSearchEngine, SearchEngine, Refreshable

public class LuceneSearchEngine
extends AbstractSearchEngine

This is the implementation of the SearchEngine interface using lucene as underlying search-engine.

Author:

Joerg Hohwiller (hohwille at users.sourceforge.net)

Field Summary

Fields

Modifier and Type	Field and Description
private org.apache.lucene.analysis.Analyzer	analyzer The lucene Analyzer.
private LuceneFieldManager	fieldManager
private org.apache.lucene.search.highlight.Formatter	highlightFormatter
private org.apache.lucene.index.IndexReader	indexReader The IndexReader used for the searcher.
private SearchQueryBuilder	queryBuilder
private SearchDependencies	searchDependencies
private org.apache.lucene.search.Searcher	searcher The actual lucene Searcher.

Constructor Summary

Constructors

Constructor and Description
LuceneSearchEngine(org.apache.lucene.index.IndexReader indexReader, org.apache.lucene.analysis.Analyzer analyzer, SearchQueryBuilder queryBuilder, org.apache.lucene.search.highlight.Formatter highlightFormatter, LuceneFieldManager fieldManager, SearchDependencies searchDependencies) The constructor.
LuceneSearchEngine(org.apache.lucene.index.IndexReader indexReader, org.apache.lucene.analysis.Analyzer analyzer, SearchQueryBuilder queryBuilder, org.apache.lucene.search.highlight.Formatter highlightFormatter, LuceneFieldManager fieldManager, SearchDependencies searchDependencies, PeriodicRefresher periodicRefresher) The constructor.

Method Summary

Modifier and Type	Method and Description
void	close() This method disposes the search-engine.
long	count(String field, String value) This method counts the number of SearchEntrys where the given field has the given value.
protected SearchHighlighter	createSearchHighlighter(org.apache.lucene.search.Query luceneQuery) This method creates a new instance of the SearchHighlighter for a SearchResultPage.
protected SearchHit	createSearchHit(int documentId, double score, SearchHighlighter searchHighlighter) This method creates an SearchHit for the given documentId and score.
SearchEntry	getEntry(int documentId)
SearchEntry	getEntry(String entryId) This method gets a entry by its technical entry-ID.
protected LuceneFieldManager	getFieldManager() This method gets the LuceneFieldManager.
protected org.apache.lucene.search.highlight.Formatter	getHighlightFormatter()
protected org.apache.lucene.search.Query	getLuceneQuery(SearchQuery query) This method gets the lucene Query for the given query.
SearchQueryBuilder	getQueryBuilder() This method gets the query builder user to create and parse queries.
protected SearchDependencies	getSearchDependencies() This method gets the SearchDependencies.
long	getTotalEntryCount() This method gets the total number of SearchEntrys in the search-index.
boolean	refresh() This method tells the search-engine to refresh explicitly.
SearchResultPage	search(SearchQuery query, int hitsPerPage) This method performs an initial search for a given query and returns the first SearchResultPage.
SearchResultPage	search(SearchQuery query, int hitsPerPage, int pageIndex, int totalHitCount) This method performs a search for a subsequent SearchResultPage of an initial search.

Methods inherited from class net.sf.mmm.search.engine.base.AbstractSearchEngine

initialize

Methods inherited from class net.sf.mmm.util.component.base.AbstractLoggableObject

getLogger

Methods inherited from class java.lang.Object

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

Field Detail

analyzer

private final org.apache.lucene.analysis.Analyzer analyzer

The lucene Analyzer.

queryBuilder

private final SearchQueryBuilder queryBuilder

See Also:

getQueryBuilder()

highlightFormatter

private final org.apache.lucene.search.highlight.Formatter highlightFormatter

See Also:

getHighlightFormatter()

fieldManager

private final LuceneFieldManager fieldManager

See Also:

getFieldManager()

searchDependencies

private final SearchDependencies searchDependencies

See Also:

getSearchDependencies()

indexReader

private org.apache.lucene.index.IndexReader indexReader

The IndexReader used for the searcher.

searcher

private org.apache.lucene.search.Searcher searcher

The actual lucene Searcher.

Constructor Detail

LuceneSearchEngine

public LuceneSearchEngine(org.apache.lucene.index.IndexReader indexReader,
                          org.apache.lucene.analysis.Analyzer analyzer,
                          SearchQueryBuilder queryBuilder,
                          org.apache.lucene.search.highlight.Formatter highlightFormatter,
                          LuceneFieldManager fieldManager,
                          SearchDependencies searchDependencies,
                          PeriodicRefresher periodicRefresher)

The constructor.

Parameters:

indexReader - is the IndexReader to access the index.

analyzer - is the Analyzer to use.

queryBuilder - is the SearchQueryBuilder query builder.

highlightFormatter - is the Formatter for highlighting.

fieldManager - is the LuceneFieldManager.

searchDependencies - are the SearchDependencies.

periodicRefresher - is the PeriodicRefresher.

LuceneSearchEngine

public LuceneSearchEngine(org.apache.lucene.index.IndexReader indexReader,
                          org.apache.lucene.analysis.Analyzer analyzer,
                          SearchQueryBuilder queryBuilder,
                          org.apache.lucene.search.highlight.Formatter highlightFormatter,
                          LuceneFieldManager fieldManager,
                          SearchDependencies searchDependencies)

The constructor.

Parameters:

indexReader - is the IndexReader.

analyzer - is the Analyzer to use.

queryBuilder - is the SearchQueryBuilder query builder.

highlightFormatter - is the Formatter for highlighting.

fieldManager - is the LuceneFieldManager.

searchDependencies - are the SearchDependencies.

Method Detail

getSearchDependencies

protected SearchDependencies getSearchDependencies()

This method gets the SearchDependencies.

Returns:

the SearchDependencies.

getFieldManager

protected LuceneFieldManager getFieldManager()

This method gets the LuceneFieldManager.

Returns:

the LuceneFieldManager.

getQueryBuilder

public SearchQueryBuilder getQueryBuilder()

This method gets the query builder user to create and parse queries.

Returns:

the query builder of this engine.

getHighlightFormatter

protected org.apache.lucene.search.highlight.Formatter getHighlightFormatter()

Returns:

the formatter

getLuceneQuery

protected org.apache.lucene.search.Query getLuceneQuery(SearchQuery query)

This method gets the lucene Query for the given query.

Parameters:

query - is the SearchQuery to "convert".

Returns:

the lucene Query.

createSearchHighlighter

protected SearchHighlighter createSearchHighlighter(org.apache.lucene.search.Query luceneQuery)

This method creates a new instance of the SearchHighlighter for a SearchResultPage.

Parameters:

luceneQuery - is the lucene Query used for highlighting.

Returns:

the SearchHighlighter.

createSearchHit

protected SearchHit createSearchHit(int documentId,
                                    double score,
                                    SearchHighlighter searchHighlighter)

This method creates an SearchHit for the given documentId and score.

Parameters:

documentId - is the technical ID of the lucene Document representing the hit.

score - is the score of the hit.

searchHighlighter - is used to create the highlighted text.

Returns:

the SearchHit.

search

public SearchResultPage search(SearchQuery query,
                               int hitsPerPage)

This method performs an initial search for a given query and returns the first SearchResultPage. The hits are in descending order of their score so the best hit is the first hit of the page .
For getting the results of a following SearchResultPage use SearchEngine.search(SearchQuery, int, int, int).

Parameters:

query - is the query of the user that wants to search. Use the query-builder to construct.

hitsPerPage - is the number of hits per page. See SearchResultPage.DEFAULT_HITS_PER_PAGE.

Returns:

the search result page for the given query at the given pageIndex.

See Also:

SearchEngine.getQueryBuilder()

search

public SearchResultPage search(SearchQuery query,
                               int hitsPerPage,
                               int pageIndex,
                               int totalHitCount)

This method performs a search for a subsequent SearchResultPage of an initial search. The hits are in descending order of their score.

Parameters:

query - is the query of the user that wants to search. Use the query-builder to construct.

hitsPerPage - is the number of hits contained in a SearchResultPage. This should be the same value as in the initial search.

pageIndex - is the page index of the requested search result. For a new query this should initially be 0. After a search result was retrieved by this method, further calls for the same query can be performed with a pageIndex greater than 0 and less than SearchResultPage.getPageCount().
It can NOT be guaranteed that the pageIndex is always valid in the sense as described above (the search index may have been modified in the meantime). An implementation has to be able to handle calls with a pageIndex greater or equal to SearchResultPage.getPageCount(). The recommended strategy is to return the last page in this case.

totalHitCount - is the total hit count expected for this query that is already known from the initial search. The implementation has to be able to handle that the search index may have been modified in the meantime and the value is NOT correct anymore. If the implementation can determine the correct total hit-count without performance overhead, it may ignore this parameter.

Returns:

the search result page for the given query at the given pageIndex.

count

public long count(String field,
                  String value)

This method counts the number of SearchEntrys where the given field has the given value. This can be useful for counting the SearchEntrys of a particular source or type. You could also do a search to figure this out but this method is supposed to be much faster.

Parameters:

field - is the name of the field.

value - is the potential value to match.

Returns:

the number of matching SearchEntrys.

getTotalEntryCount

public long getTotalEntryCount()

This method gets the total number of SearchEntrys in the search-index.

Returns:

the total number of SearchEntrys.

getEntry

public SearchEntry getEntry(String entryId)

This method gets a entry by its technical entry-ID.
This method may be useful for getting details of a hit in a new request (without rerunning the search).

Parameters:

entryId - is the ID of the requested entry.

Returns:

the entry with the given id or null if no such entry is available.

getEntry

public SearchEntry getEntry(int documentId)

Parameters:

documentId - is the technical ID of the lucene Document representing the hit.

Returns:

the document as SearchEntry.

See Also:

getEntry(String)

refresh

public boolean refresh()

This method tells the search-engine to refresh explicitly. Depending on the implementation this may cause that the search index is reread from the disk or that caches are purged. The implementation is expected to be smart in a way that it only rebuilds things if things really have changed since creation or the last call of ManagedSearchEngine.refresh().
This can be an expensive operation and should NOT be called per search request. This method refreshes the given object. This can be anything from reloading configuration to rebuilding the internal state. An invocation of this method may be expensive and should only be invoked as needed. The implementation of this method should be thread-safe if the object itself is to be used by separate consumers at all.

Returns:

true if something has changed, false otherwise. If the implementation can not determine the change it should return true.

close

public void close()

This method disposes the search-engine. This method needs to be called when the search-engine is NOT used anymore. It will free used resources (e.g. close streams, etc.). After the call of this method this search-engine AND all results retrieved from this search-engine can NOT be used anymore.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface ManagedSearchEngine

Overrides:

close in class AbstractSearchEngine