lucene的多种搜索
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2022-03-05 12:13:11
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lucene的搜索相当强大,它提供了很多辅助查询类,各自完成一种特殊的查询,也可以相互组合使用,来完成一些复杂的操作.
public class Test...{
Analyzer analyzer = new StandardAnalyzer();
RAMDirectory directory = new RAMDirectory();
/** *//**
* 创建索引
*
* @throws IOException
*/
public void index() throws IOException...{
IndexWriter indexWriter = new IndexWriter(directory,analyzer,true);
Document doc1 = new Document();
doc1.add(new Field("title","aaabbb",Store.YES,Index.TOKENIZED));
doc1.add(new Field("content","If you would like to help promote OpenOffice",Store.YES,Index.TOKENIZED));
doc1.add(new Field("time","2005",Store.YES,Index.TOKENIZED));
indexWriter.addDocument(doc1);
Document doc2 = new Document();
doc2.add(new Field("title","bbcc",Store.YES,Index.TOKENIZED));
doc2.add(new Field("content","sdfsdfsdfasdds",Store.YES,Index.TOKENIZED));
doc2.add(new Field("time","2007",Store.YES,Index.TOKENIZED));
indexWriter.addDocument(doc2);
indexWriter.optimize();
indexWriter.close();
}
// 按词条搜索
public void termSearcher() throws IOException...{
IndexSearcher searcher = new IndexSearcher(directory);
// 查询title中包含aaa
Term term = new Term("title","aaa");
Query query = new TermQuery(term);
searcher.search(query);
searcher.close();
}
// 短语搜索
public void phraseSearcher() throws IOException...{
IndexSearcher searcher = new IndexSearcher(directory);
PhraseQuery phraseQuery = new PhraseQuery();
// slop 两个项的位置之间允许的最大间隔,这里would和help中间只隔了like(to会被去掉),所以最大间隔设为1就能找到值
// 对于两个相连的关键词来说,无论坡度设为多少,都可以找到
// 对于不相连的词来说,当两个关键词相隔数小于坡度都可以找到,否则找不到
phraseQuery.setSlop(1);
phraseQuery.add(new Term("content","would"));
phraseQuery.add(new Term("content","help"));
// 如果将help放前面,would放后面,需要将would向后移动3个位置才能到help后面(to不算),所以要设为slop最少要设为3
// phraseQuery.add(new Term("content","help"));
// phraseQuery.add(new Term("content","would"));
// phraseQuery.setSlop(3);
// 短语的评分是根据项之间距离越小,评分越高,否则越小
Hits hits = searcher.search(phraseQuery);
printResult(hits);
searcher.close();
}
// 通配符搜索 WildcardQuery
// 通配符包括’?’匹配一个任意字符和’*’匹配零个或多个任意字符,例如你搜索’use*’,你可能找到’user’或者’uses’:
public void wildcardSearcher() throws IOException...{
IndexSearcher searcher = new IndexSearcher(directory);
// 与正则一样,*代表0个或多个字母,?代表0个或一个字母
// WildcardQuery与QueryParser不同的是:WildcardQuery的前缀可以为*,而QueryParser不行
WildcardQuery query = new WildcardQuery(new Term("content","a?bbb*"));
Hits hits = searcher.search(query);
printResult(hits);
searcher.close();
}
// 模糊搜索 FuzzyQuery
public void fuzzySearcher() throws IOException...{
IndexSearcher search = new IndexSearcher(directory);
// OpenOffica虽然没被索引,但能找到相近的OpenOffice
FuzzyQuery query = new FuzzyQuery(new Term("content","OpenOffica"));
Hits hits = search.search(query);
printResult(hits);
search.close();
}
// 使用前缀PrefixQuery
public void divfixSearcher() throws IOException...{
IndexSearcher search = new IndexSearcher(directory);
// 全部title前缀为a
PrefixQuery query = new PrefixQuery(new Term("title","b"));
Hits hits = search.search(query);
printResult(hits);
search.close();
}
// 范围搜索 RangeQuery
public void rangeSearcher() throws IOException...{
IndexSearcher search = new IndexSearcher(directory);
// RangeQuery query = new RangeQuery(beginTime, endTime, false);
// 开始时间,结束时间,最后一个参数表示是否包含边界条件本身,如果为false
RangeQuery query = new RangeQuery(new Term("time","2005"),new Term("time","2007"),true);
Hits hits = search.search(query);
printResult(hits);
search.close();
}
// 与或搜索BooleanQuery
//BooleanClause用于表示布尔查询子句关系的类,包括:BooleanClause.Occur.MUST,BooleanClause.Occur.MUST_NOT,BooleanClause.Occur.SHOULD。有以下6种组合:
//1.MUST和MUST:取得连个查询子句的交集。
//2.MUST和MUST_NOT:表示查询结果中不能包含MUST_NOT所对应得查询子句的检索结果。
//3.MUST_NOT和MUST_NOT:无意义,检索无结果。
//4.SHOULD与MUST、SHOULD与MUST_NOT:SHOULD与MUST连用时,无意义,结果为MUST子句的检索结果。与MUST_NOT连用时,功能同MUST。
//5.SHOULD与SHOULD:表示“或”关系,最终检索结果为所有检索子句的并集。
public void booleanSearcher() throws IOException, ParseException...{
IndexSearcher search = new IndexSearcher(directory);
QueryParser qp1 = new QueryParser("title",new StandardAnalyzer());
Query query1 = qp1.parse("aa*");
QueryParser qp2 = new QueryParser("title",new StandardAnalyzer());
Query query2 = qp2.parse("bb*");
BooleanQuery query = new BooleanQuery();
// 搜索结果的title的前双缀可以是aa,或bb
query.add(query1, BooleanClause.Occur.SHOULD);
// BooleanClause.Occur.MUST 必须
// BooleanClause.Occur.MUST_NOT 必须不是
query.add(query2, BooleanClause.Occur.SHOULD);
Hits hits = search.search(query);
printResult(hits);
search.close();
}
// 多关键的搜索 PhrasePrefixQuery
public void phrasePrefixSearcher() throws IOException...{
IndexSearcher search = new IndexSearcher(directory);
PhrasePrefixQuery query = new PhrasePrefixQuery();
// 这里两项都有可能首先被匹配
query.add(new Term[]...{new Term("content","would"),new Term("content","can")});
// 只有一项必须匹配
query.add(new Term("content","help"));
// If you would like to help promote OpenOffice
// can I help you
// slop因子的作用域为查询中的所有短语
query.setSlop(1);
// 匹配第一项为 would 或 can 第二项为help
// solp设置为1
// If you would like to help promote OpenOffice 除去if to 外,would与help的距离=1
// can I help you 的距离也=1 所以可以搜索出两条数据
Hits hits = search.search(query);
printResult(hits);
search.close();
}
// 在多个域上查询 MultiFieldQueryParser
public void multiFieldSearcher() throws IOException, ParseException...{
IndexSearcher search = new IndexSearcher(directory);
// 默认情况下的方式为Occur.SHOULD
// titile可以匹配bb,content可以匹配you
// MultiFieldQueryParser.parse(new String[]{"bb","you"},new String[]{"title","content"}, analyzer);
// titile必须匹配bb,content不能匹配
Query query = MultiFieldQueryParser.parse( new String[]...{"bb","you"},new String[]...{"title","content"},new BooleanClause.Occur[]...{Occur.MUST,Occur.MUST_NOT}, analyzer);
// title中必须包含bb content不能有bb
// Query query = MultiFieldQueryParser.parse( "bb*",new String[]{"title","content"},new BooleanClause.Occur[]{BooleanClause.Occur.MUST,BooleanClause.Occur.MUST_NOT}, analyzer);
Hits hits = search.search(query);
printResult(hits);
search.close();
}
public void printResult(Hits hits) throws IOException...{
for(int i = 0; i < hits.length(); i++)...{
Document d = hits.doc(i);
System.out.println(d.get("title"));
System.out.println(d.get("content"));
System.out.println(d.get("time"));
}
}
}
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