package com.mall.util;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.net.URLEncoder;

public class FileUtil {
	private static final String CONTENT_TYPE = "application/x-msdownload;charset=UTF-8";
	
	/*
	 * 下载文件
	 */
	public void doDownloadFile(String filePath, String filename, HttpServletRequest request, HttpServletResponse response) throws Exception {
		BufferedInputStream bis = null;
		BufferedOutputStream bos = null;
		try {
			long fileLength = new File(filePath).length();
			filename = URLEncoder.encode(filename, "UTF-8");
			response.reset();
			response.setContentType(CONTENT_TYPE);
			response.setHeader("Content-Length", String.valueOf(fileLength));
			response.addHeader("Content-Disposition","attachment; filename=\"" + filename + "\"");
			bis = new BufferedInputStream(new FileInputStream(filePath));
			bos = new BufferedOutputStream(response.getOutputStream());
			byte[] buff = new byte[2048];
			int bytesRead;
			while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
				bos.write(buff, 0, bytesRead);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (bis != null)
				bis.close();
			if (bos != null)
				bos.close();
		}
	}
	
	//删除目录底下的文件
	public void doRemoveFile(String filepath){
		try{
			File file=new File(filepath);
			if(file.exists()){
				boolean b=file.delete();
			}
		}catch(Exception e){
			e.printStackTrace();
			}
	}
}