lucene 7.x 排序

一.创建索引

@Test
    public void indexCreate() throws IOException {
        //创建分词器
        Analyzer analyzer = new StandardAnalyzer();
        IndexWriterConfig config = new IndexWriterConfig(analyzer);
        
        //指定索引存放目录以及配置参数
        Directory directory =FSDirectory.open(Paths.get("F:/luceneIndex"));
        IndexWriter writer = new IndexWriter(directory,config);
            
        //采集数据
        List<Book> bookList = bookDao.findAll();
        /*for (Book book : bookList) {
            System.out.println(book.getName());
        }*/
        //将采集的数据封装到Document中
        Document doc = null;
        for (Book book : bookList) {
            doc  = new Document();
             // store:如果是yes，则说明存储到文档域中
            //id:不分词,索引,存储
            Field id = new StringField("id",book.getId().toString(),Store.YES);
            
            //name:分词,索引,存储
            Field name = new TextField("name",book.getName(),Store.YES);
            //price:不分词,索引,存储,
            Field price = new FloatPoint("price",book.getPrice());
            
            //pic:不分词,不索引,存储,存储要添加一个同名的StoredField
            Field pic   = new StoredField("pic",book.getPic());
            //desciption:分词,索引,不存储
            Field description = new TextField("description",book.getDescription(),Store.NO);    
            doc.add(id);
            doc.add(name);
            doc.add(price);
            doc.add(new StoredField("price",book.getPrice()));//存储
            doc.add(new NumericDocValuesField("price",book.getPrice().longValue()));//排序
            doc.add(pic);
            doc.add(description);
            
            //生成索引
            writer.addDocument(doc);
        }
        
        //关闭
        writer.close();
    }

注意:创建索引时,对应price采用了FloatPoint,如果要对此字段进行存储,要添加同名的StoredField,如果要对此字段进行排序,要添加同名的NumericDocValuesField,

否则会报unexpected docvalues type异常

二.排序

//查询
    @Test
    public void indexSearch() throws IOException, ParseException {
        String[] fields = {"name","description"};
        MultiFieldQueryParser parser = new MultiFieldQueryParser(fields,new StandardAnalyzer());
        Query query = parser.parse("lucene");
        query = parser.parse("java");
        doSearch(query);
    }
    
    private void doSearch (Query query) {
        Directory directory;
        try {
            directory = FSDirectory.open(Paths.get("F:/luceneIndex"));
        
        IndexReader reader = DirectoryReader.open(directory);
        //创建IndexSearcher
        IndexSearcher searcher = new IndexSearcher(reader);
        //true表示降序
        //SortField.Type.SCORE  根据相关度进行排序(默认)
        //SortField.Type.DOC    根据文档编号或者说是索引顺序
        //SortField.Type.FLOAT(Long等),根据fieldName的数值类型进行排序
        SortField sortField = new SortField("price",SortField.Type.FLOAT,true);
        Sort sort = new Sort(sortField);
        TopDocs topDocs = searcher.search(query,10,sort);
        long count = topDocs.totalHits;
        System.out.println("匹配的总条数是----" + count);
        
        //根据相关度排序后的结果
        ScoreDoc[] docs = topDocs.scoreDocs;
        for (ScoreDoc scoreDoc : docs) {
            int docId = scoreDoc.doc;
            Document document = searcher.doc(docId);
            System.out.println("id----"+document.get("id"));
            System.out.println("name----"+document.get("name"));
            System.out.println("price----"+document.get("price"));
            /*System.out.println("pic----"+document.get("pic"));
            System.out.println("description----"+document.get("description"));*/
            System.out.println("======================");
        }
        reader.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
    }

此外还有

//Sort.RELEVANCE 根据相关度排序
//Sort.INDEXORDER 根据索引顺序排序
TopDocs topDocs = searcher.search(query,10,Sort.INDEXORDER);