lucence搜索应用结合数据库

向右看齐 2022-03-16 12:16 206阅读 0赞

lucence搜索结合数据库进行应用  
应先把数据库数据取出建立索引库并进行保存  
可定时更新，也可实时更新

>     package cn.psw.youwenbida.provider.utils;
>     
>     import org.apache.lucene.analysis.TokenStream;
>     import org.apache.lucene.document.Document;
>     import org.apache.lucene.document.Field;
>     import org.apache.lucene.document.TextField;
>     import org.apache.lucene.index.*;
>     import org.apache.lucene.queryparser.classic.QueryParser;
>     import org.apache.lucene.search.IndexSearcher;
>     import org.apache.lucene.search.Query;
>     import org.apache.lucene.search.ScoreDoc;
>     import org.apache.lucene.search.TopDocs;
>     import org.apache.lucene.search.highlight.Highlighter;
>     import org.apache.lucene.search.highlight.QueryScorer;
>     import org.apache.lucene.search.highlight.SimpleHTMLFormatter;
>     import org.apache.lucene.store.Directory;
>     import org.apache.lucene.store.FSDirectory;
>     import org.apache.lucene.util.Version;
>     import org.wltea.analyzer.lucene.IKAnalyzer;
>     
>     import java.io.File;
>     import java.io.StringReader;
>     import java.sql.*;
>     import java.util.List;
>     
>     public class TestLucene {
>         private static Connection conn = null;
>         private static Statement stmt = null;
>         private static ResultSet rs = null;
>         // 索引保存目录
>         private static String indexDir = "G:\\lucence";
>     
>         private static final String URL = "jdbc:mysql://127.0.0.1:3306/youwenbida?useUnicode=true&characterEncoding=utf8&serverTimezone=Asia/Shanghai&useSSL=false";
>         private static final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";
>         private static final String USER_NAME = "root";
>         private static final String PASSWORD = "123456";
>     
>         public static Connection getConnection() {
>             try {
>                 Class.forName(JDBC_DRIVER);
>                 conn = DriverManager.getConnection(URL, USER_NAME, PASSWORD);
>             } catch (ClassNotFoundException e) {
>                 e.printStackTrace();
>             } catch (SQLException e) {
>                 e.printStackTrace();
>             }
>             return conn;
>         }
>     
>         public static void main(String[] args) throws Exception {
>             String sql = "select pid, ptitle from problem";
>             try {
>                 stmt = getConnection().createStatement();
>                 rs = stmt.executeQuery(sql);
>                 // 给数据库创建索引,此处执行一次，不要每次运行都创建索引
>                 // 以后数据有更新可以后台调用更新索引
>                 createIndex(rs);
>                 // 显示查询结果
>                 showSearchResults("故事专心球");
>     
>             } catch (Exception e) {
>                 e.printStackTrace();
>             }
>     
>         }
>     
>         private static void showSearchResults(String keyword)
>                 throws Exception {
>             //创建或打开索引目录
>             Directory directory = FSDirectory.open(new File(indexDir));
>             IKAnalyzer analyzer = new IKAnalyzer();
>     
>             //创建indexReader对象
>             IndexReader indexReader = DirectoryReader.open(directory);
>             //创建indexSearcher对象
>             IndexSearcher indexSearcher = new IndexSearcher(indexReader);
>             //创建查询
>             Query query = new QueryParser(Version.LUCENE_47,"title", analyzer).parse(keyword);
>             //执行查询
>             //参数一  查询对象    参数二  查询结果返回的最大值
>             TopDocs topDocs = indexSearcher.search(query, 10);
>             System.out.println("找到 " + topDocs.scoreDocs.length + " 个命中.");
>             System.out.println("序号\t匹配度得分\t结果");
>     
>             SimpleHTMLFormatter simpleHTMLFormatter = new SimpleHTMLFormatter("<span style='color:red'>", "</span>");
>             Highlighter highlighter = new Highlighter(simpleHTMLFormatter, new QueryScorer(query));
>     
>             for (int i = 0; i < topDocs.scoreDocs.length; ++i) {
>                 ScoreDoc scoreDoc= topDocs.scoreDocs[i];
>                 int docId = scoreDoc.doc;
>                 Document d = indexSearcher.doc(docId);
>                 List<IndexableField> fields = d.getFields();
>                 System.out.print((i + 1));
>                 System.out.print("\t" + scoreDoc.score);
>                     TokenStream tokenStream = analyzer.tokenStream(fields.get(1).name(), new StringReader(d.get(fields.get(1).name())));
>                     String fieldContent = highlighter.getBestFragment(tokenStream, d.get(fields.get(1).name()));
>                     System.out.print("\t" + fieldContent);
>     
>                 System.out.println("<br>");
>             }
>             indexReader.close();
>         }
>     
>         private static void createIndex(ResultSet rs)  throws Exception {
>             Directory directory = FSDirectory.open(new File(indexDir));
>             IKAnalyzer analyzer = new IKAnalyzer();
>             //创建indexwriterConfig(参数分词器)
>             IndexWriterConfig indexWriterConfig = new IndexWriterConfig(Version.LUCENE_47,analyzer);
>             //创建indexwrite 对象(文件对象，索引配置对象)
>             IndexWriter indexWriter = new IndexWriter(directory,indexWriterConfig);
>             indexWriter.deleteAll();
>             // 遍历ResultSet创建索引
>             while (rs.next()) {
>                 // 创建document并添加field
>                 Document doc = new Document();
>                 doc.add(new TextField("id", rs.getString("pid"), Field.Store.YES));
>                 doc.add(new TextField("title", rs.getString("ptitle"),
>                         Field.Store.YES));
>                 // 将doc添加到索引中
>                 System.out.println(rs.getString("ptitle"));
>                 indexWriter.addDocument(doc);
>             }
>             indexWriter.close();
>         }
>     }