Jersey and @FormParam not working when charset is specified in the Content-Type

Question

It seems like Jersey 2.0 (using servlet 3.1) is not able to decode a parameter when the charset property is specified in the Content-Type header.

Answer 1

Here is a simple work-around inspired by Carlo's post. The only modification is to match '; charset=UTF-8'; otherwise, 'multipart/form-data; boundary=...' content types fail.

// IMPLEMENTATION NOTE: Resolves an issue with FormParam processing
// @see https://java.net/jira/browse/JERSEY-1978

@Provider
@PreMatching
public class ContentTypeFilter implements ContainerRequestFilter {

    @Override
    public void filter(ContainerRequestContext requestContext) throws IOException {
        MultivaluedMap<String,String> headers = requestContext.getHeaders();
        List<String> contentTypes = headers.remove(HttpHeaders.CONTENT_TYPE);
        if (contentTypes != null && !contentTypes.isEmpty()) {
            String contentType = contentTypes.get(0);
            String sanitizedContentType = contentType.replaceFirst("; charset=UTF-8", "");
            headers.add(HttpHeaders.CONTENT_TYPE, sanitizedContentType);
        }
    }
}

Answer 2

I think it's a bug.

There's a pull request open to support this use case: https://github.com/jersey/jersey/pull/24/files

In the meantime I'd suggest to use a filter to remove the offending encoding.

EDIT as per OP comments

I'm thinking on something along these lines:

@Provider
@PreMatching
public class ContentTypeFilter implements ContainerRequestFilter{

    @Override
    public void filter(ContainerRequestContext requestContext)
            throws IOException {
        MultivaluedMap<String,String> headers=requestContext.getHeaders();
        List<String> contentTypes=headers.remove(HttpHeaders.CONTENT_TYPE);
        if (contentTypes!=null && !contentTypes.isEmpty()){
            String contentType= contentTypes.get(0);
            String sanitizedContentType=contentType.replaceFirst(";.*", "");
            headers.add(HttpHeaders.CONTENT_TYPE, sanitizedContentType);
        }
    }
}