应用BooleanQuery进行组合查询时,条件之间的关系是由类BooleanClause.Occur控制的,BooleanClause.Occur中提供了三个参数值进行控制,分别是BooleanClause.Occur.MUST
BooleanClause.Occur.MUST_NOT
BooleanClause.Occur.SHOULD
它们的组合关系代表的意思如下:
1、MUST和MUST表示“与”的关系,即“并集”。
2、MUST和MUST_NOT前者包含后者不包含。
3、MUST_NOT和MUST_NOT没意义
4、SHOULD与MUST表示MUST,SHOULD失去意义;
5、SHOUlD与MUST_NOT相当于MUST与MUST_NOT。
6、SHOULD与SHOULD表示“或”的概念。
BooleanQuery的条件生成方法如下:
Term term1 = new Term(FIELD_CONTENT,"共");
TermQuery q1 = new TermQuery(term1);
BooleanQuery booleanQuery = new BooleanQuery();
booleanQuery.add(q1, BooleanClause.Occur.MUST);
package com.zhx.test;
import java.io.IOException;
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.index.CorruptIndexException;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.Searcher;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.LockObtainFailedException;
public class BooleanQuerySearcher {
/**
* @param args
*/
public static void main(String[] args) {
//索引目录
String IDNEX_PATH = "Z:/data/paoding/test_index";
//字段名
String FIELD_NAME = "field_name";
//字段名
String FIELD_CONTENT = "field_content";
//获取Paoding中文分词器
Analyzer analyzer = new StandardAnalyzer();
//建立索引
IndexWriter writer;
try {
writer = new IndexWriter(IDNEX_PATH, analyzer, true,new IndexWriter.MaxFieldLength(10));
Document doc = new Document();
Field field = new Field(FIELD_NAME, "第一条记录", Field.Store.YES,
Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS);
doc.add(field);
field = new Field(FIELD_CONTENT, "中华人民共和国", Field.Store.YES,
Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS);
doc.add(field);
writer.addDocument(doc);
doc = new Document();
field = new Field(FIELD_NAME, "第二条记录", Field.Store.YES,
Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS);
doc.add(field);
field = new Field(FIELD_CONTENT, "人民共和国", Field.Store.YES,
Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS);
doc.add(field);
writer.addDocument(doc);
writer.close();
System.out.println("Indexed success!");
//检索
IndexReader reader = IndexReader.open(IDNEX_PATH);
//生成查询条件
Term term1 = new Term(FIELD_CONTENT,"共");
Term term2 = new Term(FIELD_CONTENT,"人");
Term term3 = new Term(FIELD_NAME,"二");
TermQuery q1 = new TermQuery(term1);
TermQuery q2 = new TermQuery(term2);
TermQuery q3 = new TermQuery(term3);
BooleanQuery booleanQuery = new BooleanQuery();
booleanQuery.add(q1, BooleanClause.Occur.MUST);
booleanQuery.add(q2, BooleanClause.Occur.MUST);
booleanQuery.add(q3, BooleanClause.Occur.MUST_NOT);
Searcher searcher = new IndexSearcher(reader);
TopDocs topDocs = searcher.search(booleanQuery,10);
if (topDocs.totalHits == 0) {
System.out.println("topDocs.totalHits = 0");
} else{
ScoreDoc[] scoreDocs = topDocs.scoreDocs;
for(int i=0;i<topDocs.totalHits;i++){
int docId = scoreDocs[i].doc;
Document document = searcher.doc(docId);
System.out.println("记录"+i+":"+document.get(FIELD_NAME)+" "+document.get(FIELD_CONTENT));
}
}
reader.close();
} catch (CorruptIndexException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (LockObtainFailedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}