lucene+paoding实现全文检索
Lucene的主要逻辑图
Lucene包括两块：一是文本内容经切词后索入库；二是根据查询条件返回结果。
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根据这个图来实现非常简单，如下
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创建索引：
public String createIndex() throws Exception {// 实例化分词器,使用的是中文分词器Analyzer analyzer = new PaodingAnalyzer();// 指定要保存的文件路径并保存到FSDirectory中FSDirectory directory = FSDirectory.getDirectory(URLDecoder.decode(AnalyzerAction.class.getResource("/date/index/article/").toString(),"UTF-8").substring(6));// true表示覆盖原来已经创建的索引,如果是false表示不覆盖，而是继续添加索引IndexWriter writer = new IndexWriter(directory, analyzer, true);List list = articleManager.articleList();for (Iterator it = list.iterator(); it.hasNext();) {Document doc = new Document();Article article = (Article) it.next();doc.add(new Field("id", String.valueOf(article.getId()), Field.Store.YES,Field.Index.UN_TOKENIZED));doc.add(new Field("article_title", article.getArticleTitle(), Field.Store.YES,Field.Index.TOKENIZED));String content = FunctionUtil.Html2Text(article.getArticleContent());doc.add(new Field("article_content", content, Field.Store.YES,Field.Index.TOKENIZED));writer.addDocument(doc);}writer.optimize();writer.close();}?
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搜索结果：
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/** * 通过关键词 得到结果 */public void searchIndex(String path, String keywords) throws Exception {FSDirectory directory = FSDirectory.getDirectory(path);IndexReader reader = IndexReader.open(directory);Searcher searcher = new IndexSearcher(directory);// MultiFieldQueryParser.parse中的参数分别为:// 1.关键词// 2.要查询的字段,字符串类型的数组String[] field = { "article_title", "article_content" };// 3.两个字段的关系（与或非）BooleanClause.Occur[] flags = new BooleanClause.Occur[] {BooleanClause.Occur.SHOULD, BooleanClause.Occur.SHOULD };// 4.指明分词的时候所用的分词器Analyzer analyzer = new PaodingAnalyzer();Query query = MultiFieldQueryParser.parse(keywords, field, flags,analyzer);// 由于我们目前使用的查询是多字段查询，需要匹配度的排序// QueryScorer内置计分器query.rewrite(reader);// 用于重写query对象，目的能够让计分器识别当前的query.// 获得结果集Hits hits = searcher.search(query);for (int i = 0; i < hits.length(); i++) {Document doc = hits.doc(i);Article article = new Article();article.setId(Integer.valueOf(doc.get("id")));// titleString title = doc.get("article_title");// contentString content = doc.get("article_content");// 以上两项需要加亮// Highlighter的构造函数中需要添加两个参数// 1.高亮文字的格式(这个格式是基于html)SimpleHTMLFormatter simpleHTMLFOrmatter = new SimpleHTMLFormatter("<font color=red>", "</font>");// 2.计分器Highlighter highlighter = new Highlighter(simpleHTMLFOrmatter,new QueryScorer(query));// 关键字附近字符串的截取,截取120个字Fragmenter fragmenter = new SimpleFragmenter(120);highlighter.setTextFragmenter(fragmenter);// 针对某个字段的加亮以及截取TokenStream tokenStream = analyzer.tokenStream("article_content",new StringReader(content));//将加亮并截取的字符串取出来String highLightText = highlighter.getBestFragment(tokenStream, content);article.setArticleContent(highLightText);// 针对某个字段的加亮以及截取TokenStream title_tokenStream = analyzer.tokenStream("article_title",new StringReader(title));//将加亮并截取的字符串取出来String title_highLightText = highlighter.getBestFragment(title_tokenStream, title);article.setArticleTitle(title_highLightText);searcheResult.add(article);}reader.close();}??
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