package chapter7;


import java.io.IOException;

import org.apache.lucene.document.Field;
import org.apache.lucene.document.Document;
import org.apache.lucene.store.RAMDirectory;

import org.apache.lucene.queryParser.*;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Hits;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.analysis.standard.StandardAnalyzer;

public class BoostChangeQuery {
	static String[] ContentList = { "Lucene 使用 方便", "Lucene 功能 強大", "Lucene 開放 源碼" };
	static String[] NumberList = { "No.1", "No.2", "No.3"};
	public static void main(String[] args) throws IOException{
		searchIndex();
	}
	// 創建索引并修改boost值，改變檢索結果排序
	private static void searchIndex() throws IOException{   
		try{
			RAMDirectory ramdirectory = new RAMDirectory(); // 內存目錄
			IndexWriter writer = new IndexWriter(ramdirectory,new StandardAnalyzer(),true);
			for (int i = 0; i < ContentList.length; i++)
		    {
		        Document document = new Document(); // 創建文檔對象
		        // 創建域對象
		        Field fieldContent = new Field("Content", ContentList[i], Field.Store.YES, Field.Index.TOKENIZED);
		        Field fieldNumber  = new Field("Number", NumberList[i], Field.Store.YES, Field.Index.TOKENIZED);
		        //fieldContent.setBoost((i+1)*2);
		        document.add(fieldContent);         // 添加創建的文本域到當前文檔
		        document.add(fieldNumber);
		        //document.setBoost((i+1)*2);         // 這里設置文檔優先級
		        writer.addDocument(document);       // 完成的文檔添加到索引
		    }
			writer.close();                         // 關閉索引
		    IndexSearcher searcher = new IndexSearcher(ramdirectory);             // 創建檢索器
		    QueryParser parser = new QueryParser("Content",new StandardAnalyzer());  // 創建查詢分析器
		    Query  query = parser.parse("Lucene");    // 生成查詢對象
		    Hits rstDoc = searcher.search(query);     // 檢索結果保存Hits集合
		    for (int i = 0; i < rstDoc.length(); i++) // 遍歷獲取文檔，并讀取相關參數
		    {
		        Document doc = rstDoc.doc(i);
		        System.out.println(doc.get("Number") + " " + doc.get("Content") + " Boost: " + doc.getBoost() + ", score : " + rstDoc.score(i));
		    }
		    searcher.close();	
		} catch(ParseException e){
			System.out.println("ParseException ");
		} catch(IOException e){
			System.out.println("IOException  ");			
		}
	}
}