import java.io.File;

import java.io.IOException;

import java.util.ArrayList;

import java.util.List;

import org.apache.lucene.analysis.Analyzer;

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.document.Field.Store;

import org.apache.lucene.index.IndexWriter;

import org.apache.lucene.index.IndexWriter.MaxFieldLength;

import org.apache.lucene.queryParser.QueryParser;

import org.apache.lucene.search.IndexSearcher;

import org.apache.lucene.search.Query;

import org.apache.lucene.search.ScoreDoc;

import org.apache.lucene.search.TopDocs;

import org.apache.lucene.store.Directory;

import org.apache.lucene.store.FSDirectory;

import org.apache.lucene.util.Version;

import org.junit.Test;

import cn.itcast._domain.Article;

public class HelloWorld {

	private static Directory directory; // 索引库文件夹

	private static Analyzer analyzer; // 分词器

	static {

		try {

			directory = FSDirectory.open(new File("./indexDir"));

			analyzer = new StandardAnalyzer(Version.LUCENE_30);

		} catch (IOException e) {

			throw new RuntimeException(e);

		}

	}

	// 建立索引

	@Test

	public void testCreateIndex() throws Exception {

		// 准备数据

		Article article = new Article();

		article.setId(1);

		article.setTitle("准备Lucene的开发环境");

		article.setContent("假设信息检索系统在用户发出了检索请求后再去互联网上找答案，根本无法在有限的时间内返回结果。");

		// 放到索引库中

		// 1, 把Article转为Document

		Document doc = new Document();

		String idStr = article.getId().toString();

		doc.add(new Field("id", idStr, Store.YES, Index.NOT_ANALYZED));

		doc.add(new Field("title", article.getTitle(), Store.YES, Index.ANALYZED));

		doc.add(new Field("content", article.getContent(), Store.NO, Index.ANALYZED));

		// 2, 把Document放到索引库中

		IndexWriter indexWriter = new IndexWriter(directory, analyzer,  MaxFieldLength.UNLIMITED);

		indexWriter.addDocument(doc);

		indexWriter.close();

	}

	// 搜索

	@Test

	public void testSearch() throws Exception {

		// 准备查询条件

		String queryString = "lucene";

		// String queryString = "hibernate";

		// 运行搜索

		List<Article> list = new ArrayList<Article>();

		// ==========================================================================================

		// 1，把查询字符串转为Query对象（默认仅仅从title中查询）

		QueryParser queryParser = new QueryParser(Version.LUCENE_30, "title", analyzer);

		Query query = queryParser.parse(queryString);

		// 2，运行查询，得到中间结果

		IndexSearcher indexSearcher = new IndexSearcher(directory); // 指定所用的索引库

		TopDocs topDocs = indexSearcher.search(query, 100); // 最多返回前n条结果

		int count = topDocs.totalHits;

		ScoreDoc[] scoreDocs = topDocs.scoreDocs;

		// 3，处理结果

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

			ScoreDoc scoreDoc = scoreDocs[i];

			float score = scoreDoc.score; // 相关度得分

			int docId = scoreDoc.doc; // Document的内部编号

			// 依据编号拿到Document数据

			Document doc = indexSearcher.doc(docId);

			// 把Document转为Article

			String idStr = doc.getField("id").toString(); //doc.get("id");

			String title = doc.get("title");

			String content = doc.get("content"); // 等价于 doc.getField("content").stringValue();

			Article article = new Article();

			article.setId(Integer.parseInt(idStr));

			article.setTitle(title);

			article.setContent(content);

			list.add(article);

		}

		indexSearcher.close();

		// ==========================================================================================

		// 显示结果

		System.out.println("总结果数：" + list.size());

		for (Article a : list) {

			System.out.println("------------------------------");

			System.out.println("id = " + a.getId());

			System.out.println("title = " + a.getTitle());

			System.out.println("content = " + a.getContent());

		}

	}

}

public class Article {

	private Integer id;

	private String title;

	private String content;

	public Integer getId() {

		return id;

	}

	public void setId(Integer id) {

		this.id = id;

	}

	public String getTitle() {

		return title;

	}

	public void setTitle(String title) {

		this.title = title;

	}

	public String getContent() {

		return content;

	}

	public void setContent(String content) {

		this.content = content;

	}

}