从零开始一步一步做论坛------抛砖引玉,欢迎怕转[七]----lucene模块

好久没有更新了,今天说说最近为这个项目加的一个新功能吧,即全文检索Lucene!至于Lucene到底是什么东西,大家可以在自己学习一下,我这里只说说是怎样将其配置到我的项目中的.大家如果对我这个项目不是很了解,可以先看看前面几个帖子.

      其实说到Lucene,我也是第一次接触,以前听说过,但没有用过.搞了两天,先是看视频,看完了还是不会配到我的S2SH框架中,没办法,咱人笨.最后找项目,配合视频,终于搞定了.Lucene主要是操作其自己的索引,所以其实和数据库没有多少关系,但为了和我的项目框架保持协调性,我依然采用了dao-->service-->action这种模式,其实完全没有必要,我个人觉得有一个service层就足够了.好了,废话补多少了,直接上代码:

 

public class SearchDaoImpl implements SearchDao {

    public void save(Document doc, IndexWriter indexWriter) {
        try {
            indexWriter.addDocument(doc);
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            try {
                indexWriter.optimize();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

    }

    public void delete(Term term , IndexWriter indexWriter) {
        try {
            indexWriter.deleteDocuments(term);
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            try {
                indexWriter.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    public void update(Term term, Document doc, IndexWriter indexWriter) {
        try {
            indexWriter.updateDocument(term, doc);
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            try {
                indexWriter.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    //返回查询结果集
    public TopDocs search(Query query, IndexSearcher indexSearcher) throws Exception {
        Filter filter = null;
        return indexSearcher.search(query, filter, 10000);
    }

 

      大家可以看到,我其实连过滤器都没有写,主要就是为了熟悉这个框架和S2SH项目的整合使用.

 

public class ForumSearchServiceImpl implements ForumSearchService {
    private SearchDao searchDao;

    //保存索引
    public void saveForumIndex(List forumList)  throws Exception{
        File indexFile = new File("D:\\index");
        Analyzer analyzer = new PaodingAnalyzer();
        IndexWriter indexWriter = new IndexWriter(indexFile, analyzer, true, MaxFieldLength.LIMITED);
        List<Forum> list =forumList;

        //对所有的论坛进行索引创建
        for(Forum forum : list){
            Document doc = new Document();
            String id = forum.getId();
            Long bid = forum.getBoard().getId();
            String title = forum.getTitle();
            String detail = forum.getDetail();
            String postTime = BBSNSUtil.formatDateTime(new Date(forum.getPostTime()), Constant.formatDate);
            //因为要搜索和高亮，所以index是tokennized，TermVector是WITH_POSITIONS_OFFSETS
            doc.add(new Field("title", title, Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS));
            //利用htmlparser得到新闻内容html的纯文本
            Parser parser = new Parser();
            parser.setInputHTML(detail);
            String strings = parser.parse(null).elementAt(0).toPlainTextString().trim();
            System.out.println("-------"+strings);
            if(!(strings.length()==0)){
                doc.add(new Field("detail", strings, Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS));
            }else{
                String str = "内容为视频或者图片,不包含文字";
                doc.add(new Field("detail", str, Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS));
                System.out.println(str);
            }
            //添加时间至文档，因为要按照此字段降序排列排序，所以tokenzied,不用高亮所以TermVector是no就行了
            doc.add(new Field("postTime", postTime, Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.NO));
            //添加主键至文档，不分词，不高亮。
            doc.add(new Field("id" , id , Field.Store.YES , Field.Index.NO , Field.TermVector.NO));
            doc.add(new Field("bid" , bid.toString() , Field.Store.YES , Field.Index.NO , Field.TermVector.NO));

            searchDao.save(doc, indexWriter);
        }
        indexWriter.close();
    }

    //搜索方法
    public PageList searchFourm(String which, String keyWord, Pages pages) throws Exception{

        System.out.println("pages.getSpage()="+pages.getSpage());

        QueryResult queryResult = this.searchFourm(which, keyWord, pages.getSpage(), pages.getPerPageNum());
        PageList pl = new PageList();

        if(pages.getTotalNum()==-1){
            pages.setTotalNum(queryResult.getRecordCount());
        }
        pages.executeCount();
        queryResult = this.searchFourm(which, keyWord, pages.getSpage(), pages.getPerPageNum());
        System.out.println("queryResult.getRecordList()="+queryResult.getRecordList());
        pl.setObjectList(queryResult.getRecordList());
        pl.setPages(pages);
        return pl;
    }


    public QueryResult searchFourm(String which, String keyWord, int firstResult, int maxResult) throws Exception {
        File indexFile = new File("D:\\index");
        IndexReader reader = IndexReader.open(indexFile);
        //庖丁解牛分词器
        Analyzer analyzer = new PaodingAnalyzer();
        //指定对content还是title进行查询
        QueryParser queryParser = new QueryParser(which, analyzer);
        IndexSearcher indexSearcher = new IndexSearcher(reader);
        //对用户的输入进行查询
        Query query = queryParser.parse(keyWord);

        TopDocs topDocs = searchDao.search(query, indexSearcher);
        int recordCount = topDocs.totalHits;
        //高亮htmlFormatter对象
        SimpleHTMLFormatter sHtmlF = new SimpleHTMLFormatter("<font color='red'>", "</font>");
        //高亮对象
        Highlighter highlighter = new Highlighter(sHtmlF, new QueryScorer(query));
        //设置高亮附近的字数
        highlighter.setTextFragmenter(new SimpleFragmenter(100));

        List<ForumSearch> recordList = new ArrayList<ForumSearch>();


        // 3，取出当前页的数据
        int end = Math.min(firstResult + maxResult, topDocs.totalHits);
        for(int i = firstResult; i < end; i++){
            ScoreDoc scoreDoc = topDocs.scoreDocs[i];
            int docSn = scoreDoc.doc;//文档内部编号
            Document doc = indexSearcher.doc(docSn); // 根据编号取出相应的文档

            //取得该条索引文档
            ForumSearch fs = new ForumSearch();
            String title = doc.get("title");
            String detail = doc.get("detail");
            String id = doc.get("id");
            String bid = doc.get("bid");
            String postTime = doc.get("postTime");


            if(which.equals("title")){
                String bestFragment = highlighter.getBestFragment(analyzer, which, title);
                //获得高亮后的标题内容
                fs.setTitle(bestFragment);
                //如果内容不足100字,全部设置
                if(detail.length()<100){
                    fs.setDetail(detail);
                }else{
                    fs.setDetail(detail.substring(0, 100));
                }
            }else{
                //如果查询内容
                String bestFragment = highlighter.getBestFragment(analyzer, which, detail);
                //取得高亮内容并设置
                fs.setDetail(bestFragment);
                fs.setTitle(title);
            }
            //设置日期
            fs.setPostTime(postTime);
            fs.setId(id);
            fs.setBid(bid);
            recordList.add(fs);
        }

        return new QueryResult(recordCount, recordList);
    }

    public SearchDao getSearchDao() {
        return searchDao;
    }
    public void setSearchDao(SearchDao searchDao) {
        this.searchDao = searchDao;
    }


}

ForumSearchServiceImpl只写了两个方法,一个就是创建索引,另一个就是搜索.其中为了返回数据方便,定义了一个QueryResult结构,里面只有两个变量,这里就不粘代码了,能看懂的人自然知道那两个变量是什么,注意,这里面的方法模仿了Hibernate分页,接下来将我的Action层的代码贴出来:

public String createIndex() throws Exception{
        List<Forum> forumList = forumService.listForums();
        forumSearchService.saveForumIndex(forumList);
        return SUCCESS;
    }

    public String search() throws Exception {
        Pages pages = new Pages();
        pages.setPerPageNum(10);
        pages.setPage(this.getPage());
        pages.setFileName(basePath + "forumSearch.bbsns?action=search"+"&keyWord="+keyWord+"&which="+which);
        this.setPageList(forumSearchService.searchFourm(which, keyWord, pages));
        return "result";
    }

      其实至于搜索和创建索引,大家可以完善很多功能,比如多关键字,多条件查询,方法只要实现好,创建好索引就行了,可以实现高级搜索等功能.最近有点懒,大概写了这么点,哎...

      好了,大概差不多了,就到这里吧,如果各位有什么问题,欢迎留言探讨.

原创首发,谢谢支持!