package cn.lucene.lesson1;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field.Store;
import org.apache.lucene.document.LongField;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;
import org.junit.Before;
import org.junit.Test;
import org.wltea.analyzer.lucene.IKAnalyzer;

/**
 * txt文件索引
 */
public class TxtFileIndex2 {

	private Directory directory;

	private String indexPath = "D://lucene/index1"; // 建立索引文件的目录

	private String dirPath = "D://lucene/data"; // txt资源目录

	private Analyzer analyzer = new IKAnalyzer();

	private IndexWriter indexWriter;

	@Before
	public void init() {
		try {
			directory = FSDirectory.open(new File(indexPath));
			indexWriter = getIndexWriter(directory);
		} catch (Exception e) {
			System.out.println("索引打开异常！");
		}
	}

	/**
	 * 获得所有txt文件
	 * 
	 * @param dirPath
	 * @return
	 */
	public List<File> getFileList(String dirPath) {
		File[] files = new File(dirPath).listFiles();
		List<File> fileList = new ArrayList<File>();
		for (File file : files) {
			if (isTxtFile(file.getName())) {
				fileList.add(file);
			}
		}
		return fileList;
	}

	/**
	 * 创建索引
	 * 
	 * @throws Exception
	 */
	@Test
	public void createIndex() throws Exception {
		List<File> fileList = getFileList(dirPath);
		Document document = null;
		for (File file : fileList) {
			document = fileToDocument(file);
			indexWriter.addDocument(document);
			System.out.println("filename==" + document.get("filename"));
			indexWriter.commit();
		}
		closeWriter();
	}

	/**
	 * 判断是否是txt文件
	 * 
	 * @param fileName
	 * @return
	 */
	public boolean isTxtFile(String fileName) {
		if (fileName.lastIndexOf(".txt") > 0) {
			return true;
		}
		return false;
	}

	/**
	 * 将文件转换成Document对象
	 * 
	 * @param file
	 * @return
	 * @throws Exception
	 */
	public Document fileToDocument(File file) throws Exception {
		Document document = new Document();
		document.add(new TextField("filename", file.getName(), Store.YES));
		document.add(new TextField("content", getFileContent(file), Store.YES));
		document.add(new LongField("size", file.getTotalSpace(), Store.YES));
		return document;
	}

	/**
	 * 获得indexwriter对象
	 * 
	 * @param dir
	 * @return
	 * @throws Exception
	 */
	public IndexWriter getIndexWriter(Directory dir) throws Exception {
		IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_43, analyzer);
		return new IndexWriter(dir, iwc);
	}

	/**
	 * 关闭indexwriter对象
	 * 
	 * @throws Exception
	 */
	public void closeWriter() throws Exception {
		if (indexWriter != null) {
			indexWriter.close();
		}
	}

	/**
	 * 读取文件内容
	 * 
	 * @param file
	 * @return
	 * @throws Exception
	 */
	public String getFileContent(File file) throws Exception {
		Reader reader = new InputStreamReader(new FileInputStream(file), "GBK");
		BufferedReader br = new BufferedReader(reader);
		String result = "";
		while (br.readLine() != null) {
			result = result + "\n" + br.readLine();
		}
		br.close();
		reader.close();
		return result;
	}
}