java下载文件

final String filePath ="E:\\home\\file\\失败文件-20211230134403.xlsx";
String fileName = null;
try {
    fileName = URLEncoder.encode(filePath.substring(filePath.lastIndexOf("\\") + 1), "UTF-8");
} catch (UnsupportedEncodingException e) {
    log.error("下载模板失败", e);
    return log.error(String.format("下载错误文件失败 %s", e.toString()));
}

response.setContentType("multipart/form-data");
response.setCharacterEncoding("utf-8");
response.setHeader("Content-Disposition", "attachment;filename*= UTF-8''" + fileName);
FileInputStream exportTemp = null;
try {
    exportTemp = new FileInputStream(filePath);
} catch (FileNotFoundException e) {
    log.error("未找到磁盘文件", e);
    return log.error(String.format("未找到磁盘文件 %s", e.toString()));
}
OutputStream outputStream = null;
BufferedInputStream bis = null;
try {
    outputStream = response.getOutputStream();
} catch (IOException e) {
    log.error("下载错误文件失败", e);
    return log.error(String.format("下载错误文件失败 %s", e.toString()));
}
byte[] buff = new byte[1024];
try {
    bis = new BufferedInputStream(exportTemp);
    int i = bis.read(buff);
    while (i != -1) {
        outputStream.write(buff, 0, buff.length);
        outputStream.flush();
        i = bis.read(buff);
    }
} catch (IOException e) {
    return log.error(String.format("下载错误文件失败 %s", e.toString()));
} finally {
    if (ToolUtil.isNotEmpty(bis)) {
        try {
            bis.close();
        } catch (IOException e) {
            log.error("资源关闭异常", e);
        }
    }
    if (ToolUtil.isNotEmpty(outputStream)) {
        try {
            outputStream.close();
        } catch (IOException e) {
            log.error("资源关闭异常", e);
        }
    }
    if (ToolUtil.isNotEmpty(exportTemp)) {
        try {
            exportTemp.close();
        } catch (IOException e) {
            log.error("资源关闭异常", e);
        }
    }
    buff = null;
}