Lucene实战之初体验

前言

最早做非结构化数据搜索时用的还是lucene.net，一直说在学习java的同时把lucene这块搞一搞，这拖了2年多了，终于开始搞这块了。

开发环境

idea2016、lucene6.0、jdk1.8

使用lucene准备条件

1、pom.xml

2、测试数据。  我从博客园首页拿了几条数据，直接写了个伪Dao返回一个List<Blog>

public List<Blog> listBlogs(){
        List<Blog> list = new ArrayList<Blog>();

        Blog b1=new Blog(6538488,"风过无痕-唐","你真的了解volatile吗，关于volatile的那些事","http://www.cnblogs.com/tangyanbo/p/6538488.html");
        Blog b2=new Blog(6541312,"布鲁克石","TypeScript设计模式之职责链、状态","http://www.cnblogs.com/brookshi/p/6541312.html");
        Blog b7=new Blog(6547215,"嵘么么","轻松理解JavaScript闭包","http://www.cnblogs.com/rongmm/p/6547215.html");
        Blog b3=new Blog(6541220,"一线码农","使用Task的一些知识优化了一下同事的多线程协作取消的一串代码","http://www.cnblogs.com/huangxincheng/p/6541220.html");

        Blog b4=new Blog(6516387,"xybaby","并发与同步、信号量与管程、生产者消费者问题","http://www.cnblogs.com/xybaby/p/6516387.html");
        Blog b5=new Blog(6532713,"王福朋","深入理解 JavaScript 异步系列（4）—— Generator","http://www.cnblogs.com/wangfupeng1988/p/6532713.html");
        Blog b6=new Blog(6517788,"欢醉","入坑系列之HAProxy负载均衡","http://www.cnblogs.com/zhangs1986/p/6517788.html");

        list.add(b1);
        list.add(b2);
        list.add(b3);
        list.add(b4);
        list.add(b5);
        list.add(b6);
        list.add(b7);

        return list;
    }

IndexSearcher搜索

1、搜索体验，基于servlet开发，直接接受路径参数key

2、先写入索引

public class IndexWriterServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String index_path="d:\\indexDir";
        Directory dir=null;
        Analyzer analyzer=null;
        IndexWriterConfig config=null;
        IndexWriter indexWriter=null;
        try {
            dir =new SimpleFSDirectory(Paths.get(index_path));

            analyzer=new StandardAnalyzer();
            config =new IndexWriterConfig(analyzer);

            indexWriter =new IndexWriter(dir,config);
            BlogDao blogDao=new BlogDao();
            List<Blog> list = blogDao.listBlogs();

            for (Blog blog:list){

                Document document=new Document();
                document.add(new Field("id",blog.getId().toString(),TextField.TYPE_STORED));
                document.add(new Field("author",blog.getAuthor(),TextField.TYPE_STORED));
                document.add(new Field("title",blog.getTitle(),TextField.TYPE_STORED));
                document.add(new Field("url",blog.getUrl(),TextField.TYPE_STORED));

                indexWriter.addDocument(document);
            }
            indexWriter.commit();
            System.out.println("====索引创建完成====");
        }catch (Exception ex){
            ex.printStackTrace();
        }finally {
            if(indexWriter !=null){
                indexWriter.close();
            }
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req,resp);
    }
}

2、查询索引数据

public class IndexReaderServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Directory dir =null;
        DirectoryReader reader =null;
        IndexSearcher searcher=null;
        String index_path="d:\\indexDir";
        try{
            //dir =new RAMDirectory();
            dir =new SimpleFSDirectory(Paths.get(index_path));
            reader = DirectoryReader.open(dir);
            searcher=new IndexSearcher(reader);

            String key = req.getParameter("key");
            Query query = new TermQuery(new Term("title",key));

            TopDocs rs=searcher.search(query,100);
            resp.setContentType("text/html");
            resp.setCharacterEncoding("UTF-8");
            PrintWriter out = resp.getWriter();

            StringBuilder strHtml =new StringBuilder();
            for (int i = 0; i < rs.scoreDocs.length; i++) {
                Document firstHit = searcher.doc(rs.scoreDocs[i].doc);
                strHtml.append("title:"+firstHit.getField("title").stringValue()+"<br>");
                strHtml.append("author:"+firstHit.getField("author").stringValue()+"<br>");
                strHtml.append("<a href='"+firstHit.getField("url").stringValue()+"'>"+ firstHit.getField("url").stringValue()+"</a><br>");
                strHtml.append("====================================================<br>");
            }

            out.write(strHtml.toString());

        }catch (Exception ex){
            ex.printStackTrace();
        }finally {
            reader.close();
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req,resp);
    }
}

　　

总结

读写索引用到的几个关键类:IndexWriter、IndexSearcher、Directory、DirectoryReader、Document、TermQuery、Field