java - 在 Lucene 中搜索提供 0 个结果

Question

我正在使用 Lucene 6.4.0 并使用以下代码。

但对于每个查询，它都会返回 0 个结果。代码似乎是正确的，索引也正在构建，但我不知道哪里出了问题。

public void buildIndex(){

        Connection con = null;
        Statement stmt = null;
        ResultSet rs = null;
        IndexWriter writer=null;
        StandardAnalyzer analyzer = null;       


        analyzer = new StandardAnalyzer();




        IndexWriterConfig config = new IndexWriterConfig(analyzer);

        try{
            System.out.println("Start indexing");
            //get a reference to index directory filejdbc:mysql://localhost/MTDATABASE


            writer =  new IndexWriter(FSDirectory.open(file.toPath()), config);

            //initialize the driver class
            Class.forName("com.mysql.jdbc.Driver").newInstance();
            //get connection object
            con = DriverManager.getConnection(
                    "jdbc:mysql://"+DB_HOST_NAME+"/MTDATABASE",
                    DB_USER_NAME, DB_PASSWORD);
            //create statement object
            stmt = con.createStatement();
            //execute query
            rs = stmt.executeQuery("SELECT * FROM products");
            //iterate through result set
            while(rs.next()){
                productId = rs.getInt("productId");
                productImageName = rs.getString("productImageName");
                productCategory = rs.getString("productCategory");
                productBrandName = rs.getString("productBrandName");
                productType = rs.getString("productType");
                productName = rs.getString("productName");
                prop1 = rs.getString("prop1");
                prop2 = rs.getString("prop2");
                prop3 = rs.getString("prop3");
                prop4 = rs.getString("prop4");
                prop5 = rs.getString("prop5");
                description = rs.getString("description");
                price = rs.getInt("price");
                discount = rs.getFloat("discount");
                cashback = rs.getFloat("cashback");
                availability = rs.getString("availability");

                //create a full text field which contains name,
                //age and designation
                String fulltext = productId + " " + productImageName +
                " " + productCategory+" "+productBrandName+" "+productType+
                " " + productName + " "+prop1+" "+prop2+" "+prop3+" "+prop4+" "+prop5+
                " "+description+" "+price+" "+discount+" "+cashback+" "+availability;


                /*doc.add(new StringField("id",
                        Integer.toString(id), StringField.Store.YES));
                        doc.add(new TextField("title", title,
                        TextField.Store.YES));
                        w.addDocument(doc);*/

                //create document object


                addDoc(writer,productId,productImageName,productCategory,productBrandName,productType,
                        productName,prop1,prop2,prop3,prop4,prop5,description,price,discount,cashback,availability);
                writer.close();



            }




        }catch(Exception e){
            e.printStackTrace();
        }finally{
            try{
                if(writer!=null)
                    writer.close();
                if(rs!=null)
                    rs.close();
                if(stmt!=null)
                    stmt.close();
                if(con!=null)
                    con.close();
                System.out.println("Finished indexing");

            }catch(Exception ex){
                ex.printStackTrace();
            }

        }


    }
    public static void main(String[] args) throws Exception {

        IndexBuilder builder = new IndexBuilder();
        builder.buildIndex();
    }






private  void addDoc(IndexWriter w, int productId, String      productImageName,String productCategory,String productBrandName,String    productType,
                String productName,String prop1,String prop2,String    prop3,String prop4,String prop5,
                String description,int price,float discount,float   cashback,String availability) throws IOException {
   Document doc = new Document();
   doc.add(new StringField("produciId",Integer.toString(productId),   StringField.Store.YES));

   doc.add(new StringField("productImageName",productImageName,StringField.Store.YES));

   doc.add(new TextField("productCategory",productCategory,TextField.Store.YES));

   doc.add(new TextField("productBrandName",productBrandName,TextField.Store.YES));

   doc.add(new TextField("productType",productType,TextField.Store.YES));

   doc.add(new TextField("productName",productName,TextField.Store.YES));

   doc.add(new TextField("prop1",prop1,TextField.Store.YES));

   doc.add(new TextField("prop2",prop2,TextField.Store.YES));

   doc.add(new TextField("prop3",prop3,TextField.Store.YES));

   doc.add(new TextField("prop4",prop4,TextField.Store.YES));

   doc.add(new TextField("prop5",prop5,TextField.Store.YES));

   doc.add(new StringField("description",description,StringField.Store.YES));

   doc.add(new StringField("price",Integer.toString(price),StringField.Store.YES));

   doc.add(new StringField("discount",Float.toString(discount),StringField.Store.YES));

   doc.add(new StringField("cashback",Float.toString(cashback),StringField.Store.YES));

   doc.add(new StringField("availability",availability,StringField.Store.YES));

   w.addDocument(doc);
}

对于我正在使用的搜索:

public class Testing {

    public static void main(String[] args) {
        try{

            String LUCENE_INDEX_DIRECTORY = "C:\\lucene";

            File file = new File(LUCENE_INDEX_DIRECTORY);

            Directory index = FSDirectory.open(file.toPath());

            StandardAnalyzer analyzer = new StandardAnalyzer();

            String query = "mountain";
            QueryParser parser = new QueryParser("productName",analyzer);
            Query q = null;
            q=parser.parse(query);

            int hitsPerPage = 10;
            IndexReader reader=null;
            TopScoreDocCollector collector = null;
            IndexSearcher searcher = null;

            reader=DirectoryReader.open(index);
            searcher=new IndexSearcher(reader);

            collector = TopScoreDocCollector.create(10);
            searcher.search(q,collector);
            ScoreDoc[] hits=collector.topDocs().scoreDocs;
            System.out.println(hits.length);
            if(hits.length>0){
                for(int i=0; i<hits.length; i++){
                int docId = hits[i].doc;

                Document document = searcher.doc(docId);

                System.out.println("BrandName is: "+document.get("productBrandName")+"and ProductName is: "+document.get("productName")+
                                   "productCategory is: "+document.get("productCategory")+"and prop is:"+document.get("prop1"));

            }


        }else{
            System.out.println("Not Done");

        }

    }catch(Exception e){
        System.out.println("Not done ... ");
    }




}

}

Answer 1

如果我是你，第一件事可能就是用路加打开搜索数据库，看看你的内容是否真的被写入了搜索索引。

https://github.com/DmitryKey/luke

还要仔细检查正在填充的“productName”中是否有任何值。

一旦您确定索引的完整性良好，您就可以检查搜索词“山”是否确实是有效的搜索词。