文件下载

分享一个文件下载的工具类，代码如下，已经测试过，都可以使用。

 

package com.example.demo.test;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;

@Component
public class DownloadUtil {

    private static Logger logger = LoggerFactory.getLogger(DownloadUtil.class);

    /**
     * 文件下载方法
     * @param response
     * @param filePath
     * @param encode
     */
    public static void download(HttpServletResponse response, String filePath, String encode) {
        response.setContentType("text/html;charset=" + encode);
        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;
        String downLoadPath = filePath;
        try {
            File file = new File(downLoadPath);
            long fileLength = file.length();
            String fileName = file.getName().split("\\.")[0]+"0."+file.getName().split("\\.")[1];
            response.setContentType("application/x-msdownload;");
            response.setHeader("Content-disposition", "attachment; filename=" + new String(fileName.getBytes(encode), "ISO8859-1"));
            response.setHeader("Content-Length", String.valueOf(fileLength));
            bis = new BufferedInputStream(new FileInputStream(downLoadPath));
            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) {
            logger.error(e.getMessage());
        } finally {
            if (bis != null)
                try {
                    bis.close();
                } catch (IOException e) {
                    logger.error(e.getMessage());
                }
            if (bos != null)
                try {
                    bos.close();
                } catch (IOException e) {
                    logger.error(e.getMessage());
                }
        }
    }


    /**
     * 以流的方式下载
     * @param response
     * @param filePath
     * @param encode
     * @return response
     */
    public static HttpServletResponse downloadStream(HttpServletResponse response, String filePath, String encode) {
        response.setContentType("text/html;charset=" + encode);
        try {
            // path是指欲下载的文件的路径
            File file = new File(filePath);
            // 取得文件名
            String filename = file.getName().split("\\.")[0]+"0."+file.getName().split("\\.")[1];
            // 取得文件的后缀名
            // String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();
            // 以流的形式下载文件
            InputStream fis = new BufferedInputStream(new FileInputStream(filePath));
            byte[] buffer = new byte[fis.available()];
            fis.read(buffer);
            fis.close();
            // 清空response
            response.reset();
            // 设置response的Header
            response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.getBytes(encode), "ISO8859-1"));
            response.addHeader("Content-Length", "" + file.length());
            OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/octet-stream");
            toClient.write(buffer);
            toClient.flush();
            toClient.close();
        } catch (IOException ex) {
            logger.error(ex.getMessage());
        }
        return response;
    }

    /**
     * 下载本地文件
     * @param response
     * @param filePath
     * @param encode
     */
    public static void downloadLocal(HttpServletResponse response, String filePath,String encode) {
        response.setContentType("text/html;charset=" + encode);
        try {
            // 读到流中
            InputStream inStream = new FileInputStream(filePath); // 文件的存放路径
            // path是指欲下载的文件的路径
            File file = new File(filePath);
            // 取得文件名
            String fileName = file.getName().split("\\.")[0]+"0."+file.getName().split("\\.")[1];
            // 设置输出的格式
            response.reset();
            response.setContentType("bin");
            response.addHeader("Content-Disposition", "attachment; filename=\"" + new String(fileName.getBytes(encode), "ISO8859-1") + "\"");
            // 循环取出流中的数据
            byte[] b = new byte[2048];
            int len;
            StringBuffer sb = new StringBuffer();
            while ((len = inStream.read(b)) > 0) {
                sb.append(new String(b));
                response.getOutputStream().write(b, 0, len);
                response.getOutputStream().flush();
            }
            inStream.close();
        } catch (IOException e) {
            logger.error(e.getMessage());
        }
    }

    public static void downFile(HttpServletResponse response, String filePath) {
//        String zipPath = path.split("/WEB-INF")[0] + "/zips/" + str;
        String name = filePath.split("/")[filePath.split("/").length-1];
        //读取要下载的文件，保存到文件输入流
        try {
            // 设置头部信息
            response.setHeader(
                    "Content-disposition",
                    "attachment;filename="
                            + URLEncoder.encode(name, "UTF-8"));
            FileInputStream in = new FileInputStream(filePath);
            //创建输出流
            OutputStream out = response.getOutputStream();
            //创建缓冲区
            byte buffer[] = new byte[1024];
            int len = 0;
            //循环将输入流中的内容读取到缓冲区当中
            while((len=in.read(buffer))>0){
                //输出缓冲区的内容到浏览器，实现文件下载
                out.write(buffer, 0, len);
            }
            //关闭文件输入流
            in.close();
            //关闭输出流
            out.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}