Lucene 基础教程

Lucene PrefixQuery类
Lucene PhraseQuery类
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Lucene BooleanQuery类

BooleanQuery 用于搜索的是使用 AND，OR或NOT运算符多个查询结果的文件。

类声明

以下是org.apache.lucene.search.BooleanQuery类的声明：


public class BooleanQuery
   extends Query
      implements Iterable<BooleanClause>

字段

  • protected int minNrShouldMatch

类的构造函数

S.N. 构造函数和说明
1 BooleanQuery()
构造一个空的布尔查询。
1 BooleanQuery(boolean disableCoord)
构造一个空的布尔查询。

类方法

S.N. 方法及说明
1 void add(BooleanClause clause)
Adds a clause to a boolean query.
2 void add(Query query, BooleanClause.Occur occur)
Adds a clause to a boolean query.
3 List<BooleanClause> clauses()
Returns the list of clauses in this query.
4 Object clone()
Returns a clone of this query.
5 Weight createWeight(Searcher searcher)
Expert: Constructs an appropriate Weight implementation for this query.
6 boolean equals(Object o)
Returns true iff o is equal to this.
7 void extractTerms(Set<Term> terms)
Expert: adds all terms occurring in this query to the terms set.
8 BooleanClause[] getClauses()
Returns the set of clauses in this query.
9 static int getMaxClauseCount()
Return the maximum number of clauses permitted, 1024 by default.
10 int getMinimumNumberShouldMatch()
Gets the minimum number of the optional BooleanClauses which must be satisfied.
11 int hashCode()
Returns a hash code value for this object.
12 boolean isCoordDisabled()
Returns true iff Similarity.coord(int,int) is disabled in scoring for this query instance.
13 Iterator<BooleanClause> iterator()
Returns an iterator on the clauses in this query.
14 Query rewrite(IndexReader reader)
Expert: called to re-write queries into primitive queries.
15 static void setMaxClauseCount(int maxClauseCount)
Set the maximum number of clauses permitted per BooleanQuery.
16 void setMinimumNumberShouldMatch(int min)
Specifies a minimum number of the optional BooleanClauses which must be satisfied.
17 String toString(String field)
Prints a user-readable version of this query.

继承的方法

这个类继承了以下类方法：

  • org.apache.lucene.search.Query

  • java.lang.Object

使用


private void searchUsingBooleanQuery(String searchQuery1,
   String searchQuery2)throws IOException, ParseException{
   searcher = new Searcher(indexDir);
   long startTime = System.currentTimeMillis();
   //create a term to search file name
   Term term1 = new Term(LuceneConstants.FILE_NAME, searchQuery1);
   //create the term query object
   Query query1 = new TermQuery(term1);

   Term term2 = new Term(LuceneConstants.FILE_NAME, searchQuery2);
   //create the term query object
   Query query2 = new PrefixQuery(term2);

   BooleanQuery query = new BooleanQuery();
   query.add(query1,BooleanClause.Occur.MUST_NOT);
   query.add(query2,BooleanClause.Occur.MUST);

   //do the search
   TopDocs hits = searcher.search(query);
   long endTime = System.currentTimeMillis();

   System.out.println(hits.totalHits +
      " documents found. Time :" + (endTime - startTime) + "ms");
   for(ScoreDoc scoreDoc : hits.scoreDocs) {
      Document doc = searcher.getDocument(scoreDoc);
      System.out.println("File: "+ doc.get(LuceneConstants.FILE_PATH));
   }
   searcher.close();
}

应用程序示例

让我们创建一个测试Lucene的应用程序中使用BooleanQuery测试搜索。

步骤 描述
1 Create a project with a name LuceneFirstApplication under a packagecom.yiibai.lucene as explained in the Lucene - First Application chapter. You can also use the project created in Lucene - First Application chapter as such for this chapter to understand searching process.
2 Create LuceneConstants.java and Searcher.java as explained in the Lucene - First Applicationchapter. Keep rest of the files unchanged.
3 Create LuceneTester.java as mentioned below.
4 Clean and Build the application to make sure business logic is working as per the requirements.

LuceneConstants.java

这个类是用来提供可应用于示例应用程序中使用的各种常量。


package com.yiibai.lucene;

public class LuceneConstants {
   public static final String CONTENTS="contents";
   public static final String FILE_NAME="filename";
   public static final String FILE_PATH="filepath";
   public static final int MAX_SEARCH = 10;
}

Searcher.java

这个类用来读取就使用Lucene库的原始数据，并搜索数据的索引。


package com.yiibai.lucene;

import java.io.File;
import java.io.IOException;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.queryParser.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.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;

public class Searcher {
	
   IndexSearcher indexSearcher;
   QueryParser queryParser;
   Query query;

   public Searcher(String indexDirectoryPath) throws IOException{
      Directory indexDirectory = 
         FSDirectory.open(new File(indexDirectoryPath));
      indexSearcher = new IndexSearcher(indexDirectory);
      queryParser = new QueryParser(Version.LUCENE_36,
         LuceneConstants.CONTENTS,
         new StandardAnalyzer(Version.LUCENE_36));
   }

   public TopDocs search( String searchQuery) 
      throws IOException, ParseException{
      query = queryParser.parse(searchQuery);
      return indexSearcher.search(query, LuceneConstants.MAX_SEARCH);
   }
   
   public TopDocs search(Query query) throws IOException, ParseException{
      return indexSearcher.search(query, LuceneConstants.MAX_SEARCH);
   }

   public Document getDocument(ScoreDoc scoreDoc) 
      throws CorruptIndexException, IOException{
     return indexSearcher.doc(scoreDoc.doc);	
   }

   public void close() throws IOException{
      indexSearcher.close();
   }
}

LuceneTester.java

这个类是用来测试 Lucene 库的搜索能力。


package com.yiibai.lucene;

import java.io.IOException;

import org.apache.lucene.document.Document;
import org.apache.lucene.index.Term;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.PrefixQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.TopDocs;

public class LuceneTester {
	
   String indexDir = "E:\Lucene\Index";
   String dataDir = "E:\Lucene\Data";
   Searcher searcher;

   public static void main(String[] args) {
      LuceneTester tester;
      try {
         tester = new LuceneTester();
         tester.searchUsingBooleanQuery("record1.txt","record1");
      } catch (IOException e) {
         e.printStackTrace();
      } catch (ParseException e) {
         e.printStackTrace();
      }
   }

   private void searchUsingBooleanQuery(String searchQuery1,
      String searchQuery2)throws IOException, ParseException{
      searcher = new Searcher(indexDir);
      long startTime = System.currentTimeMillis();
      //create a term to search file name
      Term term1 = new Term(LuceneConstants.FILE_NAME, searchQuery1);
      //create the term query object
      Query query1 = new TermQuery(term1);

      Term term2 = new Term(LuceneConstants.FILE_NAME, searchQuery2);
      //create the term query object
      Query query2 = new PrefixQuery(term2);

      BooleanQuery query = new BooleanQuery();
      query.add(query1,BooleanClause.Occur.MUST_NOT);
      query.add(query2,BooleanClause.Occur.MUST);

      //do the search
      TopDocs hits = searcher.search(query);
      long endTime = System.currentTimeMillis();

      System.out.println(hits.totalHits +
            " documents found. Time :" + (endTime - startTime) + "ms");
      for(ScoreDoc scoreDoc : hits.scoreDocs) {
         Document doc = searcher.getDocument(scoreDoc);
         System.out.println("File: "+ doc.get(LuceneConstants.FILE_PATH));
      }
      searcher.close();
   }
}

数据和索引目录的创建

从record1.txt到record10.txt的文件中包含简单的名称以及学生的其他细节，并把它们放在目录E:LuceneData。这是测试数据。索引目录路径应创建为E:LuceneIndex。期间，运行 Lucene索引程序后- 索引过程中，可以看到该文件夹中创建的索引文件的列表。测试数据请下载：

运行程序：

一旦创建源，创造了原始数据，数据目录，索引目录和索引完成后，已经准备好这一步是编译和运行程序。要做到这一点，请LuceneTester.Java文件选项卡中使用Eclipse IDE可使用Run选项，或使用Ctrl+ F11来编译和运行应用程序LuceneTester。如果您的应用程序一切正常，这将在Eclipse IDE的控制台打印以下消息：

1 documents found. Time :26ms
File: E:LuceneData
ecord10.txt

Lucene PrefixQuery类
Lucene PhraseQuery类