lucene的评分功能的代码

以下是一个简单的使用Lucene评分功能的示例代码：

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.queryparser.classic.MultiFieldQueryParser;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.search.similarities.ClassicSimilarity;
import org.apache.lucene.store.FSDirectory;

import java.nio.file.Paths;

public class LuceneScoreExample {

    public static void main(String[] args) throws Exception {
        String indexDir = "index";
        String[] queryFields = {"title", "content"};
        String queryString = "lucene";

        FSDirectory directory = FSDirectory.open(Paths.get(indexDir));
        IndexReader reader = DirectoryReader.open(directory);
        IndexSearcher searcher = new IndexSearcher(reader);
        searcher.setSimilarity(new ClassicSimilarity()); // 使用ClassicSimilarity评分算法

        // 创建查询解析器
        MultiFieldQueryParser queryParser = new MultiFieldQueryParser(queryFields, new StandardAnalyzer());

        // 解析查询字符串
        Query query = queryParser.parse(queryString);

        // 执行查询
        TopDocs topDocs = searcher.search(query, 10);

        // 输出结果
        for (ScoreDoc scoreDoc : topDocs.scoreDocs) {
            Document doc = searcher.doc(scoreDoc.doc);
            System.out.println(doc.get("title") + "\t" + scoreDoc.score);
        }

        reader.close();
        directory.close();
    }
}

在上面的示例代码中，我们使用Lucene的ClassicSimilarity评分算法，并使用MultiFieldQueryParser解析查询字符串。最后，我们执行查询并输出得分最高的文档的标题和得分。