位置：首頁 > Java技術 > Lucene教學 > Lucene BooleanQuery類

Lucene BooleanQuery類

 上一篇 下一篇  

BooleanQuery 用於搜索的是使用 AND，OR或NOT運算符多個查詢結果的文件。

類聲明

以下是org.apache.lucene.search.BooleanQuery類的聲明：

public class BooleanQuery
   extends Query
      implements Iterable<BooleanClause>

字段

  • protected int minNrShouldMatch

類的構造函數

S.N. 構造函數和說明
1 BooleanQuery()
構造一個空的布爾查詢。
1 BooleanQuery(boolean disableCoord)
構造一個空的布爾查詢。

類方法

S.N. 方法及說明
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.

繼承的方法

這個類繼承了以下類方法：

  • 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();
}

應用程序示例

讓我們創建一個測試Lucene的應用程序中使用BooleanQuery測試搜索。

步驟 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

這個類是用來提供可應用於示例應用程序中使用的各種常量。

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

這個類用來讀取就使用Lucene庫的原始數據，並搜索數據的索引。

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

這個類是用來測試 Lucene 庫的搜索能力。

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();
   }
}

數據和索引目錄的創建

從record1.txt到record10.txt的文件中包含簡單的名稱以及學生的其他細節，並把它們放在目錄E:LuceneData。這是測試數據。索引目錄路徑應創建為E:LuceneIndex。期間，運行 Lucene索引程序後- 索引過程中，可以看到該文件夾中創建的索引文件的列表。測試數據請下載：data.zip

運行程序：

一旦創建源，創造了原始數據，數據目錄，索引目錄和索引完成後，已經準備好這一步是編譯和運行程序。要做到這一點，請LuceneTester.Java文件選項卡中使用Eclipse IDE可使用Run選項，或使用Ctrl+ F11來編譯和運行應用程序LuceneTester。如果您的應用程序一切正常，這將在Eclipse IDE的控製台打印以下消息：

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


 上一篇 下一篇  
極客書 © 2015-2020 . Email:   關於我們