索引和搜索Lucene索引

Question

我一直在與Lucene合作，嘗試構建索引文件和搜索文件以連接到我的數據庫，對一些行進行索引，然后對它們進行搜索。

我的兩個文件都成功編譯，但是沒有返回搜索結果。 索引器連接到數據庫並正確獲取數據，但是我不知道它是否正確保存到索引中，或者我的問題是否出在搜索文件上。

這些文件來自Lucene演示，並經過修改以查看數據庫而不是.txt文件。

索引器：

package org.apache.lucene.demo;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.LongField;
import org.apache.lucene.document.StringField;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig.OpenMode;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.Term;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;


import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Date;


public class IndexFilesDB {

  private IndexFilesDB() {}

  public static void main(String[] args) {

    String usage = "java org.apache.lucene.demo.IndexFiles"
                 + " [-index INDEX_PATH] [-docs DOCS_PATH] [-update]\n\n"
                 + "This indexes the documents in DOCS_PATH, creating a Lucene index"
                 + "in INDEX_PATH that can be searched with SearchFiles";
    String indexPath = "index";
    String docsPath = null;
    String query = null;
    String connection = null;
    boolean create = true;
    for(int i=0;i<args.length;i++) {
      if ("-index".equals(args[i])) {
        indexPath = args[i+1];
        i++;
      } else if ("-update".equals(args[i])) {
        create = false;
        i++;
      } else if ("-q".equals(args[i])) {
        query = args[i+1];
        i++;
      } else if ("-c".equals(args[i])) {
        connection = args[i+1];
        i++;
      }
    }

    if (query == null) {
      System.err.println("Usage: " + usage);
      System.exit(1);
    }

    if (connection == null) {
      System.err.println("Usage: " + usage);
      System.exit(1);
    }


    /*final File docDir = new File(docsPath);
    if (!docDir.exists() || !docDir.canRead()) {
      System.out.println("Document directory '" +docDir.getAbsolutePath()+ "' does not exist or is not readable, please check the path");
      System.exit(1);
    }*/

    Date start = new Date();
    try {
      System.out.println("Indexing to directory '" + indexPath + "'...");

      Directory dir = FSDirectory.open(new File(indexPath));
      // :Post-Release-Update-Version.LUCENE_XY:
      Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_47);
      IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_47, analyzer);

      if (create) {
        // Create a new index in the directory, removing any
        // previously indexed documents:
        iwc.setOpenMode(OpenMode.CREATE);
      } else {
        // Add new documents to an existing index:
        iwc.setOpenMode(OpenMode.CREATE_OR_APPEND);
      }

      // Optional: for better indexing performance, if you
      // are indexing many documents, increase the RAM
      // buffer.  But if you do this, increase the max heap
      // size to the JVM (eg add -Xmx512m or -Xmx1g):
      //
      // iwc.setRAMBufferSizeMB(256.0);

      IndexWriter writer = new IndexWriter(dir, iwc);
      indexDocs(writer, query, connection);

      // NOTE: if you want to maximize search performance,
      // you can optionally call forceMerge here.  This can be
      // a terribly costly operation, so generally it's only
      // worth it when your index is relatively static (ie
      // you're done adding documents to it):
      //
      // writer.forceMerge(1);

      writer.close();

      Date end = new Date();
      System.out.println(end.getTime() - start.getTime() + " total milliseconds");

    } catch (IOException e) {
      System.out.println(" caught a " + e.getClass() +
       "\n with message: " + e.getMessage());
    }
  }


  public static void indexDocs(IndexWriter writer, String query, String connection) {
    try {
        //System.out.println("Query: " + query);
        //System.out.println("Connection: " + connection);
        Connection connect = null;
        Statement statement = null;
        ResultSet resultSet = null;

        Class.forName("com.mysql.jdbc.Driver");
          // Setup the connection with the DB
          connect = DriverManager.getConnection("jdbc:mysql://XXXXXX.com/mydata?"
                  + "user=username&password=password");

          // Statements allow to issue SQL queries to the database
          statement = connect.createStatement();
          // Result set get the result of the SQL query
          resultSet = statement.executeQuery("select * from lists");

        while (resultSet.next()) {

            String listid = resultSet.getString("list_id");
            String listtitle = resultSet.getString("name");

            Document doc = new Document();

            doc.add(new StringField("listid", listid, Field.Store.YES));
            doc.add(new StringField("title", listtitle, Field.Store.YES));

            //System.out.println("listid: " + listid);
            //System.out.println("name: " + name);

            if (writer.getConfig().getOpenMode() == OpenMode.CREATE) {
            // New index, so we just add the document (no old document can be there):
            System.out.println("adding " + listtitle);
            writer.addDocument(doc);

            }


        }

    } catch (Exception e) {
      System.out.println(e);
    }

  }
}

搜索者：

package org.apache.lucene.demo;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Date;

import org.apache.lucene.analysis.Analyzer;
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.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.store.FSDirectory;
import org.apache.lucene.util.Version;

/** Simple command-line based search demo. */
public class SearchFilesDB {

  private SearchFilesDB() {}

  /** Simple command-line based search demo. */
  public static void main(String[] args) throws Exception {
    String usage =
      "Usage:\tjava org.apache.lucene.demo.SearchFiles [-index dir] [-field f] [-repeat n] [-queries file] [-query string] [-raw] [-paging hitsPerPage]\n\nSee http://lucene.apache.org/core/4_1_0/demo/ for details.";
    if (args.length > 0 && ("-h".equals(args[0]) || "-help".equals(args[0]))) {
      System.out.println(usage);
      System.exit(0);
    }

    String index = "index";
    String field = "contents";
    String queries = null;
    int repeat = 0;
    boolean raw = false;
    String queryString = null;
    int hitsPerPage = 10;

    for(int i = 0;i < args.length;i++) {
      if ("-index".equals(args[i])) {
        index = args[i+1];
        i++;
      } else if ("-field".equals(args[i])) {
        field = args[i+1];
        i++;
      } else if ("-queries".equals(args[i])) {
        queries = args[i+1];
        i++;
      } else if ("-query".equals(args[i])) {
        queryString = args[i+1];
        i++;
      } else if ("-repeat".equals(args[i])) {
        repeat = Integer.parseInt(args[i+1]);
        i++;
      } else if ("-raw".equals(args[i])) {
        raw = true;
      } else if ("-paging".equals(args[i])) {
        hitsPerPage = Integer.parseInt(args[i+1]);
        if (hitsPerPage <= 0) {
          System.err.println("There must be at least 1 hit per page.");
          System.exit(1);
        }
        i++;
      }
    }

    IndexReader reader = DirectoryReader.open(FSDirectory.open(new File(index)));
    IndexSearcher searcher = new IndexSearcher(reader);
    // :Post-Release-Update-Version.LUCENE_XY:
    Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_47);

    BufferedReader in = null;
    if (queries != null) {
      in = new BufferedReader(new InputStreamReader(new FileInputStream(queries), "UTF-8"));
    } else {
      in = new BufferedReader(new InputStreamReader(System.in, "UTF-8"));
    }
    // :Post-Release-Update-Version.LUCENE_XY:
    QueryParser parser = new QueryParser(Version.LUCENE_47, field, analyzer);
    while (true) {
      if (queries == null && queryString == null) {                        // prompt the user
        System.out.println("Enter query: ");
      }

      String line = queryString != null ? queryString : in.readLine();

      if (line == null || line.length() == -1) {
        break;
      }

      line = line.trim();
      if (line.length() == 0) {
        break;
      }

      Query query = parser.parse(line);
      System.out.println("Searching for: " + query.toString(field));

      if (repeat > 0) {                           // repeat & time as benchmark
        Date start = new Date();
        for (int i = 0; i < repeat; i++) {
          searcher.search(query, null, 100);
        }
        Date end = new Date();
        System.out.println("Time: "+(end.getTime()-start.getTime())+"ms");
      }

      doPagingSearch(in, searcher, query, hitsPerPage, raw, queries == null && queryString == null);

      if (queryString != null) {
        break;
      }
    }
    reader.close();
  }

  public static void doPagingSearch(BufferedReader in, IndexSearcher searcher, Query query, 
                                     int hitsPerPage, boolean raw, boolean interactive) throws IOException {

    // Collect enough docs to show 5 pages
    TopDocs results = searcher.search(query, 5 * hitsPerPage);
    ScoreDoc[] hits = results.scoreDocs;

    int numTotalHits = results.totalHits;
    System.out.println(numTotalHits + " total matching documents");

    int start = 0;
    int end = Math.min(numTotalHits, hitsPerPage);

    while (true) {
      if (end > hits.length) {
        System.out.println("Only results 1 - " + hits.length +" of " + numTotalHits + " total matching documents collected.");
        System.out.println("Collect more (y/n) ?");
        String line = in.readLine();
        if (line.length() == 0 || line.charAt(0) == 'n') {
          break;
        }

        hits = searcher.search(query, numTotalHits).scoreDocs;
      }

      end = Math.min(hits.length, start + hitsPerPage);

      for (int i = start; i < end; i++) {
        if (raw) {                              // output raw format
          System.out.println("doc="+hits[i].doc+" score="+hits[i].score);
          continue;
        }

        Document doc = searcher.doc(hits[i].doc);
        String path = doc.get("listid");
        System.out.println("here:" + path);
        if (path != null) {
          System.out.println((i+1) + ". " + path);
          String title = doc.get("title");
          if (title != null) {
            System.out.println("   Title: " + doc.get("title"));
          }
        } else {
          System.out.println((i+1) + ". " + "No path for this document");
        }

      }

      if (!interactive || end == 0) {
        break;
      }

      if (numTotalHits >= end) {
        boolean quit = false;
        while (true) {
          System.out.print("Press ");
          if (start - hitsPerPage >= 0) {
            System.out.print("(p)revious page, ");  
          }
          if (start + hitsPerPage < numTotalHits) {
            System.out.print("(n)ext page, ");
          }
          System.out.println("(q)uit or enter number to jump to a page.");

          String line = in.readLine();
          if (line.length() == 0 || line.charAt(0)=='q') {
            quit = true;
            break;
          }
          if (line.charAt(0) == 'p') {
            start = Math.max(0, start - hitsPerPage);
            break;
          } else if (line.charAt(0) == 'n') {
            if (start + hitsPerPage < numTotalHits) {
              start+=hitsPerPage;
            }
            break;
          } else {
            int page = Integer.parseInt(line);
            if ((page - 1) * hitsPerPage < numTotalHits) {
              start = (page - 1) * hitsPerPage;
              break;
            } else {
              System.out.println("No such page");
            }
          }
        }
        if (quit) break;
        end = Math.min(numTotalHits, start + hitsPerPage);
      }
    }
  }
}

如果有人能夠指出我犯錯的正確方向，將不勝感激！

編輯：我已經使用Luke來查看AKS建議的索引，並且可以看到索引中的術語。

我想這一定是搜索文件有問題嗎？

Answer 1

解決了！

在索引器文件中，我正在索引字段“ listid”和“ title”：

doc.add(new StringField("listid", listid, Field.Store.YES));
doc.add(new StringField("title", listtitle, Field.Store.YES));

但在搜索器文件中，將其設置在文件的最上方以查找“內容”字段：

String field = "contents";

如果其他人遇到類似的問題，我建議使用LukeAll，如AKS向我建議的那樣。 我必須使用較低版本的Lucene才能正常工作，但絕對有幫助！