How to return image as stream from JAX-RS?

Question

I'm trying to return an image in a JAX-RS web service. I was able to get this successfully working by returning FileInputStream but I'd prefer to avoid creating a File for each request.

I am using Apache CXF and Jackson (all the other resource methods produce application/json).

Code looks like this:

@GET
@Produces("image/png")
public Response getQrCode(@QueryParam("qrtext") String qrtext) {

    ByteArrayOutputStream out = QRCode.from(qrtext).to(ImageType.PNG).stream();

    return Response.ok(out).build();
}

Unfortunately, this produces the dreaded:

org.apache.cxf.jaxrs.interceptor.JAXRSOutInterceptor:376 - No message body writer has been found for response class ByteArrayOutputStream.

Here's a link to a similar post but it doesn't mention the "No message body writer" issue I'm running into.

I'd appreciate any ideas of how to deal with this issue. Thanks!

Answer 1

Just use StreamingOutput wrapper. For some reason it is unknown, but it is GREAT for providing, well, streaming output. :-)