CODEWITHSUNDEEP
jax-rsresteasy
Michael Neale
Michael Neale

Reputation: 19488

How do I do a multipart/form file upload with jax-rs?

(specifically RESTeasy)

It would be nice (for a single file) to have a method signature like: 

public void upload(@FormParam("name") ..., @FormParam("file") file: InputStream)
...

doable? or am I dreaming? doesn't seem to be that simple.

Upvotes: 29

Views: 46869

Answers (2)

rü-
rü-

Reputation: 2312

Since JAX-RS 3.1 (officially "Jakarta RESTful Web Services"; part of Jakarta EE 10), you can do:

@POST
@Consumes(MediaType.MULTIPART_FORM_DATA)
public Response postWidget(
        @FormParam("name") String name,
        @FormParam("file") EntityPart file) {
    var fileName = file.getName().orElseThrow();
    var inputStream = file.getContent();
}

This is not only a standard, it's also easier to use.

Note that I just found that the @FormParam doesn't work here in RestEasy 6.2.7 (I just submitted an issue). You'll have to read all parts and find your own:

@POST
@Consumes(MediaType.MULTIPART_FORM_DATA)
public Response postWidget(
        List<EntityPart> parts) {
    var file = parts.stream().filter(part -> "file".equals(part.getName())).findFirst().orElseThrow();
    var inputStream = file.getContent();
}

Upvotes: 2

ra9r
ra9r

Reputation: 4738

The key is to leverage the @MultipartForm annotations that comes with RESTEasy. This enables you to define a POJO that contains all the parts of the form and bind it easily.

Take for example the following POJO:

public class FileUploadForm {
    private byte[] filedata;

    public FileUploadForm() {}

    public byte[] getFileData() {
        return filedata;
    }

    @FormParam("filedata")
    @PartType("application/octet-stream")
    public void setFileData(final byte[] filedata) {
        this.filedata = filedata;
    }
}

Now all you need to do is use this POJO in the entity which would look something like this:

@POST
@Path("/upload")
@Consumes("multipart/form-data")
public Response create(@MultipartForm FileUploadForm form) 
{
    // Do something with your filedata here
}

Upvotes: 31

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