com.dpslink.flash.db.search

Class LuceneSearcher

java.lang.Object

com.dpslink.flash.db.search.LuceneSearcher

All Implemented Interfaces:

java.io.Serializable

public class LuceneSearcher
extends java.lang.Object
implements java.io.Serializable

A utility class that contains helper methods for the Jakarta-Lucene search engine. The methods in this class pertain to search request processing.

Note: The routines provided by this class are shared by the Search3 and CD search functions. Any changes made to this class should be tested with both functions.

Note: Because this class is used by the CD search function, it must be included in the cdsearch.jar file that is deployed with each CD batch.

Note: This class should not reference any Flash classes that are not accessible by the CD search function (i.e. not in cdsearch.jar).

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected static java.lang.String[]	cvIndexed_Desc_Fields Array to hold index field names used in the description query build.
protected org.apache.lucene.search.IndexSearcher	ivIdxSearcher A reference to the index searcher used to find matching hits.
protected java.lang.String	ivIndexDir The search index directory.
protected boolean	ivPrefixSearch Determines if a multi-word search is considered as individual words for prefix searchs or a phrase search.
private static long	serialVersionUID The class' serialization version id.

Constructor Summary

Constructors

Constructor and Description
LuceneSearcher(java.lang.String indexdir, boolean prefixSearch) Constructs a LuceneSearcher using the specified search index directory path.

Method Summary

Modifier and Type	Method and Description
void	closeSearcher() Closes the index searcher that was used to find hits for a search.
protected java.lang.String[]	getParsedString(java.lang.String input) Parses a given String into an array of strings based on a space delimiter.
protected java.lang.String	getQuerySafeString(java.lang.String s) Returns a string that has all the Lucene "query unsafe" characters (such as plus, minus, tilde and double quote) removed from the given string.
org.apache.lucene.search.IndexSearcher	getSearcher() Returns the current searcher.
protected org.apache.lucene.search.Query	getSearchQuery(java.lang.String searchText, java.util.ArrayList<java.lang.String[]> searchAttr) Returns the search query object for the user's entered search criteria.
protected org.apache.lucene.search.Query	getSearchQueryAttr(org.apache.lucene.search.BooleanQuery searchQ, java.util.ArrayList<java.lang.String[]> searchAttr) Returns the search query object for the attribute portion of the search.
protected boolean	getSearchQueryAttrJoin(java.util.ArrayList<java.lang.String[]> searchAttr) Determines how the product attributes are to be joined with the rest of the search.
protected boolean	getSearchQueryAttrJoin(java.lang.String[] selAttr) Determines how a selected product attribute is to be joined with the rest of the search.
protected org.apache.lucene.search.Query	getSearchQueryCode(java.lang.String searchText) Returns the search query object for the product code portion of the search.
protected org.apache.lucene.search.Query	getSearchQueryDesc(java.lang.String searchText) Returns the search query object for the description portion of the search.
protected org.apache.lucene.search.Query	getSearchQueryDesc1(java.lang.String word) Returns the search query object for the description portion of the search when the entered search string is a single word search.
protected org.apache.lucene.search.Query	getSearchQueryDesc2_Phrase(java.lang.String[] words) Returns the search query object for the description portion of the search when the entered search string is a multiple word search and the words are assumed to be a phrase.
protected org.apache.lucene.search.Query	getSearchQueryDesc2_Prefix(java.lang.String[] words) Returns the search query object for the description portion of the search when the entered search string is a multiple word search where each word is searched as a prefix (i.e.
protected org.apache.lucene.search.Query	getSearchQueryDesc2(java.lang.String[] words) Returns the search query object for the description portion of the search when the entered search string is a multiple word search.
void	openSearcher() Opens the index searcher that is used to find hits for a search.
protected java.lang.String	preprocessIndexData(java.lang.String s) Looks for and adjusts special situations before a string is indexed.
org.apache.lucene.search.TopDocs	search(java.lang.String searchText, java.util.ArrayList<java.lang.String[]> searchAttr, java.lang.String topMostCat, int maxHits) Returns the set of hits for the products that match the given set of search criteria.

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

private static final long serialVersionUID

The class' serialization version id.

See Also:

Constant Field Values

cvIndexed_Desc_Fields

protected static java.lang.String[] cvIndexed_Desc_Fields

Array to hold index field names used in the description query build.

ivIndexDir

protected java.lang.String ivIndexDir

The search index directory.

ivIdxSearcher

protected org.apache.lucene.search.IndexSearcher ivIdxSearcher

A reference to the index searcher used to find matching hits.

ivPrefixSearch

protected boolean ivPrefixSearch

Determines if a multi-word search is considered as individual words for prefix searchs or a phrase search.

Constructor Detail

LuceneSearcher

public LuceneSearcher(java.lang.String indexdir,
                      boolean prefixSearch)

Constructs a LuceneSearcher using the specified search index directory path.

Parameters:

indexdir - (String) The full path to the search index directory.

prefixSearch - (boolean) True if words should be considered a for prefix searching.

Method Detail

closeSearcher

public void closeSearcher()

Closes the index searcher that was used to find hits for a search.

openSearcher

public void openSearcher()
                  throws java.lang.Exception

Opens the index searcher that is used to find hits for a search.

Throws:

java.lang.Exception - - if an error occurs while opening the search index reader.

getSearcher

public org.apache.lucene.search.IndexSearcher getSearcher()

Returns the current searcher.

Returns:

IndexSearcher.

search

public org.apache.lucene.search.TopDocs search(java.lang.String searchText,
                                               java.util.ArrayList<java.lang.String[]> searchAttr,
                                               java.lang.String topMostCat,
                                               int maxHits)
                                        throws java.lang.Exception

Returns the set of hits for the products that match the given set of search criteria. The invoker is responsible for closing the searcher when the returned hit results are no longer needed (see closeSearcher()).

Parameters:

searchText - (String) The entered search string.

searchAttr - (ArrayList) The selected product attributes.

maxHits - (int) The maximum number of matches that should be returned.

Returns:

TopDocs - The set of hits for the search's matching products.

Throws:

java.lang.Exception - - if an error occurs while performing the search.

getParsedString

protected java.lang.String[] getParsedString(java.lang.String input)

Parses a given String into an array of strings based on a space delimiter.

Parameters:

input - (String) The String to be parsed.

Returns:

String[] - A String array containing the parsed results.

getQuerySafeString

protected java.lang.String getQuerySafeString(java.lang.String s)

Returns a string that has all the Lucene "query unsafe" characters (such as plus, minus, tilde and double quote) removed from the given string.

Parameters:

s - (String) The String to be processed.

Returns:

String - A String containing the processed results.

getSearchQuery

protected org.apache.lucene.search.Query getSearchQuery(java.lang.String searchText,
                                                        java.util.ArrayList<java.lang.String[]> searchAttr)
                                                 throws java.lang.Exception

Returns the search query object for the user's entered search criteria.

Parameters:

searchText - (String) The entered search string.

searchAttr - (ArrayList) The selected product attributes.

Returns:

Query - The search query object.

Throws:

java.lang.Exception - - if an error occurs while creating the search query object.

getSearchQueryCode

protected org.apache.lucene.search.Query getSearchQueryCode(java.lang.String searchText)
                                                     throws java.lang.Exception

Returns the search query object for the product code portion of the search.

Parameters:

searchText - (String) The entered search string.

Returns:

Query - The product code search query object.

Throws:

java.lang.Exception - - if an error occurs while creating the search query object.

getSearchQueryDesc

protected org.apache.lucene.search.Query getSearchQueryDesc(java.lang.String searchText)
                                                     throws java.lang.Exception

Returns the search query object for the description portion of the search.

Parameters:

searchText - (String) The entered search string.

Returns:

Query - The description search query object.

Throws:

java.lang.Exception - - if an error occurs while creating the search query object.

getSearchQueryDesc1

protected org.apache.lucene.search.Query getSearchQueryDesc1(java.lang.String word)
                                                      throws java.lang.Exception

Returns the search query object for the description portion of the search when the entered search string is a single word search.

Parameters:

word - (String) The search word.

Returns:

Query - The description search query object.

Throws:

java.lang.Exception - - if an error occurs while creating the search query object.

getSearchQueryDesc2

protected org.apache.lucene.search.Query getSearchQueryDesc2(java.lang.String[] words)
                                                      throws java.lang.Exception

Returns the search query object for the description portion of the search when the entered search string is a multiple word search.

Parameters:

words - (String[]) The search words.

Returns:

Query - The description search query object.

Throws:

java.lang.Exception - - if an error occurs while creating the search query object.

getSearchQueryDesc2_Phrase

protected org.apache.lucene.search.Query getSearchQueryDesc2_Phrase(java.lang.String[] words)
                                                             throws java.lang.Exception

Returns the search query object for the description portion of the search when the entered search string is a multiple word search and the words are assumed to be a phrase.

Parameters:

words - (String[]) The search words.

Returns:

Query - The description search query object.

Throws:

java.lang.Exception - - if an error occurs while creating the search query object.

getSearchQueryDesc2_Prefix

protected org.apache.lucene.search.Query getSearchQueryDesc2_Prefix(java.lang.String[] words)
                                                             throws java.lang.Exception

Returns the search query object for the description portion of the search when the entered search string is a multiple word search where each word is searched as a prefix (i.e. mon matches monitor, monday, monet, etc).

Parameters:

words - (String[]) The search words.

Returns:

Query - The description search query object.

Throws:

java.lang.Exception - - if an error occurs while creating the search query object.

getSearchQueryAttr

protected org.apache.lucene.search.Query getSearchQueryAttr(org.apache.lucene.search.BooleanQuery searchQ,
                                                            java.util.ArrayList<java.lang.String[]> searchAttr)
                                                     throws java.lang.Exception

Returns the search query object for the attribute portion of the search.

Parameters:

searchQ - (BooleanQuery) The query to which the attribute portion is to be added.

searchAttr - (ArrayList) The selected product attributes.

Returns:

Query - The product attribute search query object.

Throws:

java.lang.Exception - - if an error occurs while creating the search query object.

getSearchQueryAttrJoin

protected boolean getSearchQueryAttrJoin(java.util.ArrayList<java.lang.String[]> searchAttr)
                                  throws java.lang.Exception

Determines how the product attributes are to be joined with the rest of the search. The determination is based on the first selected attribute's conjunction (AND or OR).

Parameters:

searchAttr - (ArrayList) The selected product attributes.

Returns:

boolean - true if the attribute join is "AND", false if the attribute join is "OR".

Throws:

java.lang.Exception - - if an error occurs while determining the join.

getSearchQueryAttrJoin

protected boolean getSearchQueryAttrJoin(java.lang.String[] selAttr)
                                  throws java.lang.Exception

Determines how a selected product attribute is to be joined with the rest of the search. The determination is based on the selected attribute's conjunction (AND or OR).

Parameters:

selAttr - (String[]) A selected product attribute.

Returns:

boolean - true if the attribute join is "AND", false if the attribute join is "OR".

Throws:

java.lang.Exception - - if an error occurs while determining the join.

preprocessIndexData

protected java.lang.String preprocessIndexData(java.lang.String s)

Looks for and adjusts special situations before a string is indexed. Executes the same preprocess routine as the indexer.

Parameters:

s - (String) The characters to process.

Returns:

String - the resulting string with special situations adjusted.