Dropwizard升级HttpServletRequest请求null指针异常

Question

I have upgraded the dropwizard version from 1.3.12 to 2.0.12. After running my app again I am getting null pointer exception in HttpServletRequest. Here is the example code

    import javax.servlet.http.HttpServletRequest;

    public class myClass{

    @Context
    private HttpServletRequest request;
    
    @GET
    @Path("/authenticate")
    @Produces(MediaType.TEXT_HTML)
    public Response getAuthentication(@QueryParam("myParam") String myParam) {
     System.out.println(request);
    }
}

just so you know, I have removed the extra bits from the code to make it simple. Any suggestions why getting HttpServletRequestas null? with dropwizard version 1.3.12 it is working fine.

Answer 1

Migrating resource instances with field context injections to Dropwizard 2.0 involves pushing the field into a parameter in the desired endpoint, so your class would turn out like this:

public class MyClass {

@GET
@Path("/authenticate")
@Produces(MediaType.TEXT_HTML)
public Response getAuthentication(final @Context HttpServletRequest request,
                                  @QueryParam("myParam") String myParam) {
    System.out.println(request);
    return Response.ok().build();
}

}

See the Dropwizard Migration Guide