从零开始一步一步做论坛------抛砖引玉,欢迎拍砖[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!