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。