lucene 学习笔记-排序
1.排序

Lucene有内置的排序用IndexSearcher.search(query,sort)但是功能并不理想。我们需要自己实现自定义的排序。

这样的话得实现两个接口: ScoreDocComparator, SortComparatorSource

用IndexSearcher.search(query,new Sort(new SortField(String Field,SortComparatorSource)));

就看个例子吧：

这是一个建立索引的例子：

public void IndexSort() throws IOException {         IndexWriter writer = new IndexWriter("C:\\\\indexStore",new StandardAnalyzer(),true);         Document doc = new Document();         doc.add(new Field("sort","1",Field.Store.YES,Field.Index.TOKENIZED));         writer.addDocument(doc);         doc = new Document();         doc.add(new Field("sort","4",Field.Store.YES,Field.Index.TOKENIZED));         writer.addDocument(doc);         doc = new Document();         doc.add(new Field("sort","3",Field.Store.YES,Field.Index.TOKENIZED));         writer.addDocument(doc);         doc = new Document();         doc.add(new Field("sort","5",Field.Store.YES,Field.Index.TOKENIZED));         writer.addDocument(doc);         doc = new Document();        doc.add(new Field("sort","9",Field.Store.YES,Field.Index.TOKENIZED));         writer.addDocument(doc);         doc = new Document();         doc.add(new Field("sort","6",Field.Store.YES,Field.Index.TOKENIZED));         writer.addDocument(doc);         doc = new Document();         doc.add(new Field("sort","7",Field.Store.YES,Field.Index.TOKENIZED));         writer.addDocument(doc);         writer.close(); } //下面是搜索的例子: public void SearchSort1() throws IOException, ParseException {         IndexSearcher indexSearcher = new IndexSearcher("C:\\\\indexStore");         QueryParser queryParser = new QueryParser("sort",new StandardAnalyzer());         Query query = queryParser.parse("4");         Hits hits = indexSearcher.search(query);         System.out.println("有"+hits.length()+"个结果");         Document doc = hits.doc(0);         System.out.println(doc.get("sort")); } public void SearchSort2() throws IOException, ParseException{         IndexSearcher indexSearcher = new IndexSearcher("C:\\\\indexStore");         //这个地方前面没有提到，它是用于范围的Query可以看一下帮助文档. Query query = new RangeQuery(new Term("sort","1"),new Term("sort","9"),true);        Hits hits = indexSearcher.search(query,new Sort(new SortField("sort",new MySortComparatorSource())));         System.out.println("有"+hits.length()+"个结果");         for(int i=0;i<hits.length();i++) {             Document doc = hits.doc(i);             System.out.println(doc.get("sort"));         } } public class MyScoreDocComparator implements ScoreDocComparator{     private Integer[] sort;     public MyScoreDocComparator(String s,IndexReader reader, String fieldname) throws IOException{         sort = new Integer[reader.maxDoc()];         for(int i = 0;i<reader.maxDoc();i++){            Document doc =reader.document(i);             sort[i]=new Integer(doc.get("sort"));         }     }     public int compare(ScoreDoc i, ScoreDoc j){         if(sort[i.doc]>sort[j.doc])            return 1;         if(sort[i.doc]<sort[j.doc])             return -1;         return 0;     }     public int sortType(){      return SortField.INT;     }     public Comparable sortValue(ScoreDoc i){         return new Integer(sort[i.doc]);     } } public class MySortComparatorSource implements SortComparatorSource {     private static final long serialVersionUID = -9189690812167655465L;     public ScoreDocComparator newComparator(IndexReader reader, String fieldname)throws IOExceptio{         if(fieldname.equals("sort"))             return new MyScoreDocComparator("sort",reader,fieldname);         return null;     } } 

//SearchSort1()输出的结果没有排序,SearchSort2()就排序了。