Question

I am not able to pass my own object through @FormParam with Jersey. It is always null. I have method like this:

@POST
@Path("search")
@Consumes({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML})
@Produces({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML})
public SearchResult search(
        @FormParam("record") MyObject record,
        @FormParam("offset") Integer offset,
        ...) {
    ...
}

When I try to pass the MyObject, it’s always null. The parameter offset is passed correctly.

Client side in JavaScript for illustration:

$.ajax({
    'url': url,
    'type': 'POST',
    'dataType': 'json', 'contentType': 'application/json',
    'data': {'record': record, 'offset': 123}
})

I thought that it might be a problem with jQuery, so I tried to change the parameter to some nonsence 'data': {'record': 'string instead of json', 'offset': 123} and I got 400 (Bad Request). I also checked the body of the request and it seemed alright.

But when I change the method to look like this:

public SearchResult search(MyObject record) { ... }

And the client script accordingly:

$.ajax({
    'url': url,
    'type': 'POST',
    'dataType': 'json', 'contentType': 'application/json',
    'data': JSON.stringify(record)
})

The MyObject is obtained correctly.

I tried to use GET method with the same results.

Is it possible that it’s a bug in Jersey or am I missing something?

Answer 1

@FormParam only works for application/x-www-form-urlencoded media type. So, the second approach (the one that works for you) is the right way to receive JSON message entities.