设置响应头在浏览器中下载

        1. 设置响应头
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        headers.setContentDispositionFormData("attachment", "folder.zip");

        // 使用ResponseEntity.ok()创建ResponseEntity，并将StreamingResponseBody和响应头作为参数
        return ResponseEntity.ok().headers(headers).body(responseBody);

       2.这段代码设置响应头在浏览器中下载；

@Controller
public class DownloadController {

    @GetMapping("/download")
    @ResponseBody
    public ResponseEntity<StreamingResponseBody> download() throws IOException {
        // 要打包的文件夹路径
        String folderPath = "C:/java/folder/";

        // 创建临时文件，用于存储生成的zip文件
        File tempFile = File.createTempFile("temp", ".zip");

        try {
            // 创建文件输出流
            FileOutputStream fos = new FileOutputStream(tempFile);
            // 创建压缩输出流
            ZipOutputStream zos = new ZipOutputStream(fos);

            // 调用递归方法进行文件夹压缩
            zipFolder(folderPath, "", zos);

            // 关闭压缩输出流和文件输出流
            zos.close();
            fos.close();

            // 创建StreamingResponseBody，将文件输出流的内容写入输出流
            StreamingResponseBody responseBody = output -> {
                FileInputStream fis = new FileInputStream(tempFile);
                byte[] buffer = new byte[1024];
                int len;
                while ((len = fis.read(buffer)) > 0) {
                    output.write(buffer, 0, len);
                }
                fis.close();
            };

            // 设置响应头
            HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
            headers.setContentDispositionFormData("attachment", "folder.zip");

            // 使用ResponseEntity.ok()创建ResponseEntity，并将StreamingResponseBody和响应头作为参数
            return ResponseEntity.ok()
                    .headers(headers)
                    .body(responseBody);
        } catch (IOException e) {
            e.printStackTrace();
            return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
        } finally {
            // 删除临时文件
            tempFile.delete();

            // 删除文件夹
            File folder = new File(folderPath);
            deleteFolder(folder);
        }
    }

    // 递归压缩文件夹的方法，同上例
    // ...

    // 删除文件夹的递归方法
    private void deleteFolder(File folder) {
        if (folder.isDirectory()) {
            File[] files = folder.listFiles();
            if (files != null) {
                for (File file : files) {
                    deleteFolder(file);
                }
            }
        }
        folder.delete();
    }
}