EzyHTTP Upload file

Updated at 1685686579000
Same as every HTTP server framewords, EzyHttp allows you upload file, too. And we recommend you let's use asynchronous API, to know why, please take a look the explanation here.

1. FileUploader

EzyHTTP provides to you an convenient FileUploader class. It wraps ResourceUploadManager, an event loop like below:

And the event loop will do like this:

    take a inputstream/outputstream pair from the queue:
        take 1024 bytes from the inputstream of the requested file and push to client's outputstream
        if there is no remain data in the inputstream
            then response to the client: call to the callback and done
            push the the inputstream/outputstream pair back to the queue

2. Enable file upload configuration

To enable file upload, you can add the configuration to your application.properties file like this:


If you want to set queue capacity and thread pool size, buffer size, you can setup:

resources.upload.capacity=[an integer value]
resources.upload.thread_pool_size=[an integer value]
resources.upload.buffer_size=[an integer value]

3. Upload file asynchronously

To upload a file asynchronously with FilerUploader, you can do like this:

    public class FileController {
        private final FileUploadService fileUploadService;
        public void uploadPost(
            RequestArguments requestArguments
        ) throws Exception {
    public class FileUploadService {
        private final FileUploader fileUploader;
        public void accept(HttpServletRequest request) throws Exception {
                () -> System.out.println("Upload finished")
        public void accept(
            HttpServletRequest request,
            Part part,
            EzyExceptionVoid callback
        ) {
            String fileName = part.getSubmittedFileName();
            File file = new File("files/" + fileName);
            AsyncContext asyncContext = request.getAsyncContext();
            fileUploader.accept(asyncContext, part, file, callback);

4. Upload file Synchronously

To upload a file synchronously, you can do like this:

    public class FileController {
        public ResponseEntity uploadSyncPost(
            HttpServletRequest request
        ) throws Exception {
            Part part = request.getPart("file");
            String fileName = part.getSubmittedFileName();
            File file = new File("files/" + fileName);
            InputStream inputStream = part.getInputStream();
            byte[] buffer = new byte[1024];
            try (OutputStream outputStream = new FileOutputStream(file)) {
                while (true) {
                    int read = inputStream.read(buffer);
                    if (read > 0) {
                        outputStream.write(buffer, 0, read);
                    } else {
            return ResponseEntity.noContent();

Next step

You can see How to download a file.