lucene使用sort进行结果查询排序

利用sort对查询结果进行排序示例

• 对于要排序的字段，在索引的时候可以Field.Index.NOT_ANALYZE

package com.cn;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.RAMDirectory;
import org.apache.lucene.util.Version;

public class TTT {

	public static void main(String []args)throws Exception {
		String [] ids = {"1","2","3","4","5"};
		String [] bookName = {"java start","java begin","java in action","java web","java ssh"};
		String [] page = {"300","400","256","302","279"};
		String [] price = {"89","99","70","60","120"};
		Directory directory = new RAMDirectory();
		
		IndexWriter indexWriter = new IndexWriter(directory,new IndexWriterConfig(Version.LUCENE_34, new StandardAnalyzer(Version.LUCENE_34)));
		for(int i = 0;i < ids.length;i++){
			Document doc = new Document();
			doc.add(new Field("id",ids[i],Field.Store.YES,Field.Index.NOT_ANALYZED));
			doc.add(new Field("bookName",bookName[i],Field.Store.YES,Field.Index.ANALYZED));
			doc.add(new Field("page",page[i],Field.Store.YES,Field.Index.NOT_ANALYZED));
			doc.add(new Field("price",price[i],Field.Store.YES,Field.Index.NOT_ANALYZED));
			indexWriter.addDocument(doc);
		}
		System.out.println("total:"+indexWriter.numDocs());
		indexWriter.close();
		Term term = new Term("bookName","java");
		Query query = new TermQuery(term);
		IndexSearcher indexSearcher = new IndexSearcher(directory);
		Sort sort = new Sort();
		SortField sortField = new SortField("price", SortField.INT);
		sort.setSort(sortField);
        //参数10的意思为返回10条记录
		TopDocs topDocs = indexSearcher.search(query, 10, sort);
		ScoreDoc [] scoreDoc = topDocs.scoreDocs;
		for(int i=0;i<scoreDoc.length;i++){
			Document d = indexSearcher.doc(scoreDoc[i].doc);
			System.out.println(d.get("bookName")+"\t"+d.get("page")+"\t"+d.get("price"));
		}
	}
}

结果：
total:5java web    302    60java in action    256    70java start    300    89java begin    400    99java ssh    279    120
如果在sort加上第三个参数：true是否反序，结果如下 sort默认的排序是升序排列的
total:5
java ssh	279	120
java begin	400	99
java start	300	89
java in action	256	70

相关API如下：

BYTE           Sort using term values as encoded Bytes.

CUSTOM           Sort using a custom Comparator.

DOC           Sort by document number (index order).

DOUBLE           Sort using term values as encoded Doubles.

FIELD_DOC           Represents sorting by document number (index order).

FIELD_SCORE           Represents sorting by document score (relevance).

FLOAT           Sort using term values as encoded Floats.

INT           Sort using term values as encoded Integers.

LONG         Sort using term values as encoded Longs.

SCORE           Sort by document score (relevance).

SHORT           Sort using term values as encoded Shorts.

STRING           Sort using term values as Strings.

STRING_VAL           Sort using term values as Strings, but comparing by value (using String.compareTo) for all comparisons.

Constructor Summary

SortField(String field, FieldCache.Parser parser)           Creates a sort by terms in the given field, parsed to numeric values using a custom FieldCache.Parser.

SortField(String field, FieldCache.Parser parser, boolean reverse)           Creates a sort, possibly in reverse, by terms in the given field, parsed to numeric values using a custom FieldCache.Parser.

SortField(String field, FieldComparatorSource comparator)           Creates a sort with a custom comparison function.

SortField(String field, FieldComparatorSource comparator, boolean reverse)           Creates a sort, possibly in reverse, with a custom comparison function.

SortField(String field, int type)           Creates a sort by terms in the given field with the type of term values explicitly given.

SortField(String field, int type, boolean reverse)           Creates a sort, possibly in reverse, by terms in the given field with the type of term values explicitly given.

SortField(String field, Locale locale)           Creates a sort by terms in the given field sorted according to the given locale.

SortField(String field, Locale locale, boolean reverse)           Creates a sort, possibly in reverse, by terms in the given field sorted according to the given locale.