Dropwizard example giving 400 error when creating new resource

To get helpful message regarding 400 error, register this on jersey:

environment.jersey().register(new JsonProcessingExceptionMapper(true));

It will give more detailed message on 400 response, useful for debugging.

A little background: Dropwizard utilizes Jersey, and Jersey is what ultimately gives you back the 400 Bad Request response, probably along with a vague and laconic message.

In order to see exactly what did bother Jackson (which in turn bothered Jersey), I started out by sending a blank (empty) JSON object and see whether it was accepted (it did - and all the fields in the POJO where zero-initialized). Then I started to add fields, sending each such object along, until I reached the problematic field (in my case it was a boolean field which should have been a Boolean).

I think I can spot two difficulties in your POJO (the Document class):

1. The getters/setters should be annotated with @JsonProperty.

2. Try to change Id's type to Long (nullable long). If you are concerned about getting a null in that field, you can have the getter return a zero or any default value instead.

I faced the same issue. The errors are suppressed and not passed properly in the stack trace. What I did was to add a try catch around the function. Then added a debugger point in the exception. I was able to figure out the exact reason.

You could try something like this.

@POST@UnitOfWorkpublic Document createDocument(Document document) throws Exception{....}

Add debugger points in the Exception class. You will find out the exact reason of the parsing failure.

Hope I am clear and it helps!