关于lucene搜索时排序的问题

为什么80%的码农都做不了架构师&＃xff1f;>>>

在Lucene4.6中&＃xff0c;想要实现搜索结果按照时间倒序的效果&＃xff1a;如果两个文档得分相同&＃xff0c;那么就按照发布时间倒序排列&＃xff1b;否则就按照分数排列。这种效果在 Lucene4.6中实现起来极其简单&＃xff0c;直接利用search接口的Sort参数即可达成&＃xff0c;完全不需要像某些人说的重写Similarity那么麻烦。三两行代码的事情&＃xff0c;体现了Make it simple, stupid的精髓。

package com.hankcs.test; import org.apache.lucene.analysis.Analyzer; import org.apache.lucene.document.*; import org.apache.lucene.index.*; import org.apache.lucene.queries.CustomScoreQuery; import org.apache.lucene.queries.function.FunctionQuery; import org.apache.lucene.queryparser.classic.ParseException; import org.apache.lucene.queryparser.classic.QueryParser; import org.apache.lucene.search.*; import org.apache.lucene.store.Directory; import org.apache.lucene.store.LockObtainFailedException; import org.apache.lucene.store.RAMDirectory; import org.apache.lucene.util.Version;import org.wltea.analyzer.lucene.IKAnalyzer; import java.io.IOException; /** * &＃64;author hankcs */ public class TestSortByTime{ public static void main(String[] args) { // Lucene Document的主要域名 String fieldName &＃61; "text"; // 实例化IKAnalyzer分词器 Analyzer analyzer &＃61; new IKAnalyzer(); Directory directory &＃61; null; IndexWriter iwriter; IndexReader ireader &＃61; null; IndexSearcher isearcher; try { //索引过程********************************** //建立内存索引对象 directory &＃61; new RAMDirectory(); //配置IndexWriterConfig IndexWriterConfig iwConfig &＃61; new IndexWriterConfig(Version.LUCENE_46, analyzer); iwConfig.setOpenMode(IndexWriterConfig.OpenMode.CREATE_OR_APPEND); iwriter &＃61; new IndexWriter(directory, iwConfig); //写入索引 for (int i &＃61; 0; i < 3; &＃43;&＃43;i) { int year &＃61; 2004 &＃43; i; Document doc &＃61; new Document(); doc.add(new TextField(fieldName, year &＃43; "全民突击攻略", Field.Store.YES));doc.add(new IntField("date", year * 10000 &＃43; 1111, Field.Store.YES)); iwriter.addDocument(doc);} // 加入一个干扰文档 Document doc &＃61; new Document(); doc.add(new TextField(fieldName, "天天酷跑攻略", Field.Store.YES)); doc.add(new IntField("date", 20141111, Field.Store.YES)); iwriter.addDocument(doc); iwriter.close(); //搜索过程********************************** //实例化搜索器 ireader &＃61; DirectoryReader.open(directory); isearcher &＃61; new IndexSearcher(ireader); String keyword &＃61; "全民突击攻略"; //使用QueryParser查询分析器构造Query对象 QueryParser qp &＃61; new QueryParser(Version.LUCENE_46, fieldName, analyzer); Query query &＃61; qp.parse(keyword); System.out.println("Query &＃61; " &＃43; query); //搜索相似度最高的5条记录 Sort sort &＃61; new Sort(new SortField("text", SortField.Type.SCORE), new SortField("date", SortField.Type.INT, true)); TopDocs topDocs &＃61; isearcher.search(query, 5, sort); System.out.println("命中&＃xff1a;" &＃43; topDocs.totalHits); //输出结果 ScoreDoc[] scoreDocs &＃61; topDocs.scoreDocs; for (int i &＃61; 0; i < Math.min(5, scoreDocs.length); i&＃43;&＃43;){ Document targetDoc &＃61; isearcher.doc(scoreDocs[i].doc); System.out.print(targetDoc.getField(fieldName).stringValue()); System.out.print(" , " &＃43; targetDoc.getField("date").numericValue()); System.out.println(" , " &＃43; scoreDocs[i].score); } } catch (CorruptIndexException e) { e.printStackTrace(); } catch (LockObtainFailedException e) { e.printStackTrace(); } catch (IOException e){ e.printStackTrace(); } catch (ParseException e) { e.printStackTrace(); } finally { if (ireader !&＃61; null) {try{ ireader.close(); } catch (IOException e) { e.printStackTrace(); } } if (directory !&＃61; null) { try { directory.close(); } catch (IOException e) {e.printStackTrace(); } } } }}