FileMultiUploadField

<fileMultiUpload id="fileMultiUploadField"
                 caption="Upload"/>

(1)
@Autowired
private FileMultiUploadField fileMultiUploadField;
@Autowired
private TemporaryStorage temporaryStorage;
@Autowired
private Notifications notifications;

@Subscribe
public void onInit(InitEvent event) {
    (2)
    fileMultiUploadField.addQueueUploadCompleteListener(queueUploadCompleteEvent -> { (3)
        for (Map.Entry<UUID, String> entry : fileMultiUploadField.getUploadsMap().entrySet()) { (4)
            UUID fileId = entry.getKey();
            String fileName = entry.getValue();
            FileRef fileRef = temporaryStorage.putFileIntoStorage(fileId, fileName); (5)
        }
        notifications.create()
                .withCaption("Uploaded files: " + fileMultiUploadField.getUploadsMap().values())
                .show();
        fileMultiUploadField.clearUploads(); (6)
    });
    fileMultiUploadField.addFileUploadErrorListener(queueFileUploadErrorEvent ->
            notifications.create()
                    .withCaption("File upload error")
                    .show());
}