下载工具类

public class DownloadUtils {
private static Logger logger = LoggerFactory.getLogger(com.hikvision.idatafusion.util.DownloadUtils.class);

public DownloadUtils() {
}

/**
 * 从服务器下载文件
 * @param fileName
 * @param filepath
 * @param request
 * @param response
 * @throws Exception
 */
public static void download(String fileName, String filepath, HttpServletRequest request, HttpServletResponse response) throws Exception {
    response.setContentType("text/html;charset=utf-8");
    request.setCharacterEncoding("UTF-8");
    BufferedInputStream bis = null;
    BufferedOutputStream bos = null;
    //String ctxPath = request.getSession().getServletContext().getRealPath("/") + filepath;

    try {
        File file = new File(filepath);
        if (!file.exists()) {
            logger.warn("download agent is error ! messages --->> " + filepath + " is not exists !");
        }

        response.setContentType("application/x-msdownload;");
        response.setHeader("Content-disposition", "attachment; filename=" + new String(fileName.getBytes("utf-8"), "ISO8859-1"));
        response.setHeader("Content-Length", String.valueOf(file.length()));
        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 var13) {
        logger.warn("download agent is error ! messages --->> " + var13.fillInStackTrace());
    } finally {
        if (bis != null) {
            bis.close();
        }

        if (bos != null) {
            bos.close();
        }

    }

}

/**
 * 下载二进制文件
 * @param fileName 文件名
 * @param bytes 文件的二进制字节数组
 * @param request
 * @param response
 * @throws Exception
 */
public static void downloadFromBytes(String fileName,byte[] bytes, HttpServletRequest request, HttpServletResponse response) throws Exception {
    response.setContentType("application/octet-stream;charset=ISO8859-1");
    request.setCharacterEncoding("UTF-8");
    BufferedOutputStream bos = null;
    try {
        response.setHeader("Content-disposition", "attachment; filename=" + new String(fileName.getBytes(), "ISO8859-1"));
        bos = new BufferedOutputStream(response.getOutputStream());
        bos.write(bytes);
        response.flushBuffer();
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        if (bos != null) {
            bos.close();
        }
    }

}


/**
 * 从类路径下下载文件
 * @param response 返回
 * @param filePath 文件所在类路径
 * @param fileName 下载的文件名
 */
public static void downLoadFromClasspath(HttpServletResponse response, String filePath, String fileName) {
    InputStream inputStream = null;
    ResourceLoader resourceLoader = new DefaultResourceLoader();
    Resource resource=resourceLoader.getResource(filePath);
    logger.info(resource.toString());
    BufferedInputStream bis=null;
    try {
        inputStream=resource.getInputStream();
        response.addHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename="+ URLEncoder.encode(fileName, "UTF-8"));
        response.addHeader(HttpHeaders.CONTENT_TYPE,"application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        BufferedOutputStream bos = new BufferedOutputStream(
                response.getOutputStream());
        bis = new BufferedInputStream(inputStream);
        byte[] b=new byte[1024];
        int i = bis.read(b);
        while (i != -1) {
            bos.write(b, 0, b.length);
            bos.flush();
            i = bis.read(b);
        }
    } catch (IOException e) {
        e.printStackTrace();

    } finally {
        if (inputStream != null) {
            try {
                inputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if (bis != null) {
            try {
                bis.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

}