前端通过url下载服务器中文件

妖狐艹你老母 2024-04-17 05:51 94阅读 0赞

项目中需要实现一个功能，通过点击<a href=“url”>，后台经过controller，将文件下载到客户端。

##### 后台controller调用如下方法即可，无需返回值 #####

private void downFile(HttpServletRequest request, HttpServletResponse response, File downFile) {
        try {
            String range = null;
            // 特殊头处理
            if (null != request.getHeader("RANGE")) {// 断点续传的头
                range = request.getHeader("RANGE");
            }
            if (null != request.getHeader("Range")) {
                range = request.getHeader("Range");
            }
            response.setContentType("application/x-msdownload");
            int fileLength = Integer.parseInt(Long.toString(downFile.length()));
            response.setContentLength(fileLength);
            response.setHeader("Content-Disposition", "attachment;filename=" + new String(downFile.getName().getBytes("gb2312"), "ISO8859-1"));// 处理默认文件名的中文问题
            int startPos = 0;
            if (null != range) {// 断点续传
                startPos = Integer.parseInt(range.replaceAll("bytes=", "").replaceAll("-$|-\\d+$", ""));
            }
            if (startPos == 0) {
                FileCopyUtils.copy(new FileInputStream(downFile), response.getOutputStream());
            } else {// 断点续传
                response.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT);
                if (startPos != 0) {
                    /** 设置Content-Range: bytes [文件块的开始字节]-[文件的总大小 - 1]/[文件的总大小] **/
                    StringBuffer sb = new StringBuffer("bytes ");
                    sb.append(Long.toString(startPos));
                    sb.append("-");
                    sb.append(Long.toString(fileLength - 1));
                    sb.append("/");
                    sb.append(Long.toString(fileLength));
                    response.setHeader("Content-Range", sb.toString());
                }
                if (startPos < fileLength) {
                    fileLength = fileLength - startPos;
                    response.getOutputStream().write(FileUtils.readFileToByteArray(downFile), (int) startPos, (int) fileLength);
                }
            }
            response.getOutputStream().flush();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }