How to validate file upload? [Play Framework] - file-upload

Question

I have a simple bean, like that:
package models;
import play.data.validation.Constraints;
public class Upload
{
#Constraints.Required
#Constraints.MinLength(4)
#Constraints.MaxLength(40)
public String name;
#Constraints.Required
public String inputFile;
}
and form, like that:
#form(action = routes.Application.submit(), 'enctype -> "multipart/form-data") {
#inputText(
uploadForm("name"),
'_label -> "Name"
)
#inputFile(
uploadForm("inputFile"),
'_label -> "Queries"
)
}
What is the best way to validate inputFile?
Is it possible do to that with annotations?
#Required constraint does not work at all.
I want it to be selected + add some limitation on size.

Answer 1

make your form like:
<input type="file" name="inputFile">
In you submit method add this:
// from official documentation
public static Result submit() {
MultipartFormData body = request().body().asMultipartFormData();
FilePart file = body.getFile("inputFile");
if (inputFile != null) {
String fileName = picture.getFilename();
String contentType = picture.getContentType();
File file = picture.getFile();
// method the check size
if(!validateFileSize){
return redirect(routes.Application.index()); // error in file size
}
return ok("File uploaded");
} else {
// here comes the validation
flash("error", "Missing file");
return redirect(routes.Application.index());
}
}

Answer 2

Something like the following, maybe?
MultipartFormData body = request().body().asMultipartFormData();
if (!body.getFiles().isEmpty()) {
// do your work
}