使用Lucene通过改变boost的值来改变文档的得分

/*

* 通过改变boost的值来改变文档的得分

* 在这个例子中Doc3的得分是最少的，

* 加入我想把doc3的得分变高，把他放到网页的第一条，

* 那么就是用doc3.setBoost(2f);方法就可以实现

* */

package score;

import java.io.IOException;

import org.apache.lucene.analysis.standard.StandardAnalyzer;

import org.apache.lucene.document.Document;

import org.apache.lucene.document.Field;

import org.apache.lucene.document.Field.Index;

import org.apache.lucene.index.IndexWriter;

import org.apache.lucene.index.Term;

import org.apache.lucene.search.Hits;

import org.apache.lucene.search.IndexSearcher;

import org.apache.lucene.search.TermQuery;

public class ChangeBoost{

public ChangeBoost(String INDEX_STORE_PATH)

{

try{

IndexWriter writer = new IndexWriter(INDEX_STORE_PATH, new StandardAnalyzer(), true);

writer.setUseCompoundFile(false);

//创建3个文档

Document doc1 = new Document();

Document doc2 = new Document();

Document doc3 = new Document();

Field f1 = new Field("bookname", "ab bc", Field.Store.YES, Index.TOKENIZED);

Field f2 = new Field("bookname", "ab bc cd", Field.Store.YES, Index.TOKENIZED);

Field f3 = new Field("bookname", "ab bc de ff gg ss", Field.Store.YES, Index.TOKENIZED);

doc1.add(f1);

doc2.add(f2);

doc3.add(f3);

writer.addDocument(doc1);

writer.addDocument(doc2);

doc3.setBoost(2f);

writer.addDocument(doc3);

writer.close();

IndexSearcher searcher = new IndexSearcher(INDEX_STORE_PATH);

TermQuery q = new TermQuery(new Term("bookname", "bc"));

Hits hits = searcher.search(q);

for(int i = 0; i < hits.length(); i++){

Document doc = hits.doc(i);

//与之匹配的文档

System.out.println(doc.get("bookname") + "\t\t");

//文档所得分数

System.out.println(hits.score(i));

//这里通过解释的方法，来了解这个分数是怎么回事

System.out.println(searcher.explain(q, hits.id(i)).toString());

}

}catch(IOException e){

e.printStackTrace();

}

}

public static void main(String[] args) {

// TODO Auto-generated method stub

ChangeBoost cb = new ChangeBoost("E:\\Lucene项目\\索引文件");

}

}

改变前的截图：

加上处理后截图：