/*
* Copyright (c) JForum Team
* All rights reserved.
*
* Redistribution and use in source and binary forms,
* with or without modification, are permitted provided
* that the following conditions are met:
*
* 1) Redistributions of source code must retain the above
* copyright notice, this list of conditions and the
* following disclaimer.
* 2) Redistributions in binary form must reproduce the
* above copyright notice, this list of conditions and
* the following disclaimer in the documentation and/or
* other materials provided with the distribution.
* 3) Neither the name of "Rafael Steil" nor
* the names of its contributors may be used to endorse
* or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT
* HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
* IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE
*
* Created on 18/07/2007 22:05:37
*
* The JForum Project
* http://www.jforum.net
*/
package net.jforum.search;
import java.io.IOException;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;
import net.jforum.exceptions.SearchException;
import org.apache.log4j.Logger;
import org.apache.lucene.analysis.Token;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.analysis.standard.ParseException;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.Term;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.Hits;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.TermQuery;
/**
* @author Rafael Steil
* @version $Id: LuceneSearch.java,v 1.38 2007/10/05 03:22:37 rafaelsteil Exp $
*/
public class LuceneSearch implements NewDocumentAdded
{
private static final Logger logger = Logger.getLogger(LuceneSearch.class);
private IndexSearcher search;
private LuceneSettings settings;
private LuceneResultCollector contentCollector;
public LuceneSearch(LuceneSettings settings,
LuceneResultCollector contentCollector)
{
this.settings = settings;
this.contentCollector = contentCollector;
this.openSearch();
}
/**
* @see net.jforum.search.NewDocumentAdded#newDocumentAdded()
*/
public void newDocumentAdded()
{
try {
this.search.close();
this.openSearch();
}
catch (Exception e) {
throw new SearchException(e);
}
}
/**
* @see net.jforum.dao.SearchDAO#search(net.jforum.search.SearchArgs)
*/
public SearchResult search(SearchArgs args)
{
return this.performSearch(args, this.contentCollector, null);
}
public Document findDocumentByPostId(int postId)
{
Document doc = null;
try {
Hits hit = this.search.search(new TermQuery(
new Term(SearchFields.Keyword.POST_ID, String.valueOf(postId))));
if (hit.length() > 0) {
doc = hit.doc(0);
}
}
catch (IOException e) {
throw new SearchException(e);
}
return doc;
}
private SearchResult performSearch(SearchArgs args, LuceneResultCollector resultCollector, Filter filter)
{
SearchResult result;
try {
StringBuffer criteria = new StringBuffer(256);
this.filterByForum(args, criteria);
this.filterByKeywords(args, criteria);
this.filterByDateRange(args, criteria);
Query query = new QueryParser("", new StandardAnalyzer()).parse(criteria.toString());
if (logger.isDebugEnabled()) {
logger.debug("Generated query: " + query);
}
Hits hits = filter == null ?
this.search.search(query, this.getSorter(args))
: this.search.search(query, filter, this.getSorter(args));
if (hits != null && hits.length() > 0) {
result = new SearchResult(resultCollector.collect(args, hits, query), hits.length());
}
else {
result = new SearchResult(new ArrayList(), 0);
}
} catch (ParseException e) {
result = new SearchResult(new ArrayList(), 0);
}catch (Exception e) {
throw new SearchException(e);
}
return result;
}
private Sort getSorter(SearchArgs args)
{
Sort sort = Sort.RELEVANCE;
if ("time".equals(args.getOrderBy())) {
sort = new Sort(SearchFields.Keyword.POST_ID, "DESC".equals(args.getOrderDir()));
}
return sort;
}
private void filterByDateRange(SearchArgs args, StringBuffer criteria)
{
if (args.getFromDate() != null) {
criteria.append('(')
.append(SearchFields.Keyword.DATE)
.append(": [")
.append(this.settings.formatDateTime(args.getFromDate()))
.append(" TO ")
.append(this.settings.formatDateTime(args.getToDate()))
.append(']')
.append(')');
}
}
private void filterByKeywords(SearchArgs args, StringBuffer criteria)
{
String[] keywords = this.analyzeKeywords(args.rawKeywords());
for (int i = 0; i < keywords.length; i++) {
if (args.shouldMatchAllKeywords()) {
criteria.append(" +");
}
criteria.append('(')
.append(SearchFields.Indexed.CONTENTS)
.append(':')
.append(QueryParser.escape(keywords[i]))
.append(") ");
}
}
private void filterByForum(SearchArgs args, StringBuffer criteria)
{
if (args.getForumId() > 0) {
criteria.append("+(")
.append(SearchFields.Keyword.FORUM_ID)
.append(':')
.append(args.getForumId())
.append(") ");
}
}
private String[] analyzeKeywords(String contents)
{
try {
TokenStream stream = this.settings.analyzer().tokenStream("contents", new StringReader(contents));
List tokens = new ArrayList();
while (true) {
Token token = stream.next();
if (token == null) {
break;
}
tokens.add(token.termText());
}
return (String[])tokens.toArray(new String[0]);
}
catch (IOException e) {
throw new SearchException(e);
}
}
private void openSearch()
{
try {
this.search = new IndexSearcher(this.settings.directory());
}
catch (IOException e) {
throw new SearchException(e.toString(), e);
}
}
}