package com.matrix.system.hive.plugin.util;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URLEncoder;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

import javax.servlet.http.HttpServletResponse;

public class FileDownload {

	/**
	 * @param response
	 * @param filePath
	 *            //文件完整路径(包括文件名和扩展名)
	 * @param fileName
	 *            //下载后看到的文件名
	 * @return 文件名
	 */
	public static void fileDownload(final HttpServletResponse response, String filePath, String fileName) throws Exception {

		byte[] data = toByteArray2(filePath);
		fileName = URLEncoder.encode(fileName, "UTF-8");
		response.reset();
		response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
		response.addHeader("Content-Length", "" + data.length);
		response.setContentType("application/octet-stream;charset=UTF-8");
		OutputStream outputStream = new BufferedOutputStream(response.getOutputStream());
		outputStream.write(data);
		outputStream.flush();
		outputStream.close();
		response.flushBuffer();

	}

	/**
	 * 读取到字节数组2
	 * 
	 * @param filePath
	 * @return
	 * @throws IOException
	 */
	public static byte[] toByteArray2(String filePath) throws IOException {

		File f = new File(filePath);
		if (!f.exists()) {
			throw new FileNotFoundException(filePath);
		}

		FileChannel channel = null;
		FileInputStream fs = null;
		try {
			fs = new FileInputStream(f);
			channel = fs.getChannel();
			ByteBuffer byteBuffer = ByteBuffer.allocate((int) channel.size());
			while ((channel.read(byteBuffer)) > 0) {
			}
			return byteBuffer.array();
		} catch (IOException e) {
			e.printStackTrace();
			throw e;
		} finally {
			try {
				channel.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
			try {
				fs.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

	public static String getClasspath() {
		String path = (String.valueOf(Thread.currentThread().getContextClassLoader())).replaceAll("file:/", "").replaceAll("%20", " ").trim();
		if (path.indexOf(":") != 1) {
			path = File.separator + path;
		}
		return path;
	}
}