Hello,
I'm using CXF 2.7.5 for some REST APIs, most of which return JSON. I'd
like to return a nice custom error message that tells the user calling
the API what fields failed when the user provides bad input; e.g.
passing in a string for an Integer parameter. Essentially I'd like to
intercept input error handling (either by type conversion or bean
validation) and tell the user: "here are the input fields that I didn't
understand", rather than a blank page with a 404.
The whole point is to avoid having API arguments all be strings that we
have to manually convert to their native types, catch exception, and
creating the nice error message. I.e. I don't want to do:
@GET @PATH("/{foo}/{bar}")
public Response foo(@PathParam("foo") Integer foo,
@PathParam("bar") Integer bar) {
List<String> failedInputNames = new ArrayList<String>();
if (cannotParseInt(foo)) failedInputNames.add("foo");
if (cannotParseInt(bar)) failedInputNames.add("bar");
if (!failedInputNames.isEmpty() {
return Response.status(NOT_FOUND, "there was an input error
with these fields: " + failedInputNames);
}
... do stuff ...
}
I would like to automate this so it automagically happens for all our
API endpoints; if any inputs cannot be bound, or fail bean validation
(e.g. @Pattern or @NotNull), the API endpoint code remains simple and
clean:
@GET @PATH("/{foo}/{bar}")
public Response foo(@PathParam("foo") Integer foo,
@PathParam("bar") Integer bar) {
... do stuff ...
}
In Spring this is possible by adding a BindingResult argument to the
method; if it's present, Spring doesn't throw an exception, but tells
you via BindingResult which input fields failed, and why. This makes it
very easy to write custom code to tell the user in a friendly way what
input failed.
Is something like this possible via CXF? It's not obvious to me that
CXF will generate a consistent Exception type I can intercept.
Thanks,
Raul
