We Keep Coding

Jersey JAX-RS annotating interface not the implementation class results in error

I got an interface annotated with JAX-RS annotations.
In the implementation class itself I just override the methods of the interface; not overriding annotations or anything.
I get the following error:
The class {name} is an interface and cannot be instantiated.
I've tried making a jar of my annotated interface and put it in .war \lib folder, yet the error persists.
If it matters, I'm using JBoss's embedded Tomcat.
Here's the interface:
#javax.ws.rs.Path( "/jerseytesting.HelloWorldService" )
public interface HelloWorldService {
#javax.ws.rs.POST
#javax.ws.rs.Path( "/Greet" )
#javax.ws.rs.Consumes({"application/protobuf", "application/json"})
#javax.ws.rs.Produces({"application/protobuf", "application/json"})
jerseytesting.Twirpproto.HelloResponse greet(jerseytesting.Twirpproto.HelloRequest request);
}
And here is the implementation:
public class Twirpy implements Twirpproto.HelloWorldService {
#Override
public HelloResponse greet(HelloRequest request) {
HelloResponse helloResponse = HelloResponse.newBuilder().setResponse("Hello, " + request.getName()).build();
return helloResponse;
}
}

From the API documentation:
JAX-RS annotations MAY be used on the methods and method parameters of
a super-class or an implemented interface.
So, only the method annotations can be on the interface.
The concrete class should have the #Path. Only then JAX-RS will know to create an instance of that concrete class.
Like so:
#javax.ws.rs.Path( "/jerseytesting.HelloWorldService" )
public class Twirpy implements Twirpproto.HelloWorldService {
#Override
public HelloResponse greet(HelloRequest request) {
HelloResponse helloResponse = HelloResponse.newBuilder().setResponse("Hello, " + request.getName()).build();
return helloResponse;
}
}

Override value of custom runtime annotation applied on Interface

tl;dr: I'm overriding a method annotation of an interface on a child-child class, but the annotation's value is not being override.
I'm surprised I didn't found the answer for this question on this or any other site, so I think it must be something wrong with my implementation, but I can't figure it out.
I have the following custom annotation:
#Retention(RetentionPolicy.RUNTIME)
#Target(ElementType.METHOD)
#Inherited //This only applies to class annotations, but I tried it anyway
public #interface MyRolesAllowed {
String[] value();
}
And it's used on this interface:
#Produces(MediaType.APPLICATION_JSON)
public interface IRESTfulCRUDResource<T> {
#GET
#Path("/")
#MyRolesAllowed("ADMIN")
public Response ws(#Context UriInfo uriInfo);
}
That's implemented as:
#Stateless
#Produces(MediaType.APPLICATION_JSON)
public abstract class BaseCRUDResource<T> implements IRESTfulCRUDResource<T> {
#Override
public Response wsQuery(#Context UriInfo uriInfo) {
//...
}
}
That I just override in this class to change the default annotation:
#Stateless
#Path("/something")
public class SomeResource extends BaseCRUDResource<Someclass> {
#Override
#MyRolesAllowed({"ADMIN", "USER"})
public Response wsQuery(#Context UriInfo uriInfo) {
return super.wsQuery(uriInfo);
}
}
This is all hosted on a Wildfly server, and I'm using the following interceptor to process the annotation:
#Provider
#Priority(Priorities.AUTHORIZATION)
public class AuthorizationInterceptor implements ContainerRequestFilter {
public void filter(ContainerRequestContext requestContext) throws IOException {
Method resourceMethod = resourceInfo.getResourceMethod();
// I checked and at this point:
// resourceInfo.getResourceClass().getSimpleName() == "SomeResource"
String[] roles = resourceMethod.getAnnotation(MyRolesAllowed.class).value();
// Now, I checked and at this point:
// roles = {"ADMIN"}
// In my understanding, it should be {"ADMIN", "USER"},
// because I'm overriding the annotation on the child
// class, and resourceMethod points to the child method.
// What's wrong?
}
}
So, as stated on the last comment, I was expecting the parent's annotation to be override by the child's one, but it's not happening. This question is an example of annotation's value override.
I tried to use resourceMethod.getAnnotationsByType as well, but it provides the same values.
Am I misunderstanding something?
Update: as #JohnBollinger pointed in the comments section, I checked and resourceMethod.getDeclaringClass() == IRESTfulCRUDResource, so it's counterintuitive but ResourceInfo's getResourceMethod points to the parent method but getResourceClass points to the child class.

Access iriInfo in called Method

This code works to access the uriInfo:
#Path("/testing")
public class Testing {
#javax.ws.rs.core.Context UriInfo uriInfo;
#POST
#Path("/test2")
#Produces(MediaType.TEXT_PLAIN)
public Response test2(
#FormParam("sessionId") String sessionId ) {
String currentUserId = Utils.setup(sessionId);
String accessPath = uriInfo.getAbsolutePath().toASCIIString();
System.out.println("The client used this URI to reach this resource method: " + uriInfo.getAbsolutePath().toASCIIString());
// Utils.test3("print this");
return Response.ok("Test 2 ended").build();
}
When I try to access the uriInfo in the called method Utils.test3("print this"); Here:
public class Utils {
#javax.ws.rs.core.Context static UriInfo uriInfo;
public static String setup(String sessionId) {
if (!com.retailapppartners.Utils.validSession(sessionId)) {
throw new WebApplicationException(Response.Status.UNAUTHORIZED);
}
String currentUserId = com.retailapppartners.Utils.getUserFromSession(sessionId);
MDC.put("user-id", currentUserId);
return currentUserId;
}
public static void test3(String message) {
System.out.println(message);
String path = uriInfo.getPath();
// System.out.println("The client used this URI: " + uriInfo.getAbsolutePath().toASCIIString());
return;
}
This fails with null pointer exception. I want to see the path uri in the called method to confirm security for all methods in my utils called method. I have searched hi and low for called examples of this. Thanks

Use the #Context annotation to inject an instance of UriInfo into an field variable or method parameter of your resource class
e.g. #1
public String find(#Context UriInfo uri){}
e.g. #2
public class RESTResource{
#Context
private UriInfo uri;
}

Continuing with my comment.. into an answer
Like I said, you can't just decide to inject it anywhere you want. The class being injected into needs to be managed by the JAX-RS runtime, as it's the one that will be doing the injecting. A resource class is managed, a filter provider is managed, that's why you can inject into them. You're utility class is not. And in any case, I don't think it would even work for a [static] "utility" class (even if you were to somehow get it managed) because of the static nature.
Let me just first mention, that UriInfo is specific to each request. static, by nature is "global". You cannot inject it as a static field.
One solution I can see is to make the Utils class (and methods) non-static, and use the underlying injection framework to inject an instance of the Utils class, where ever you need it. This way, if the Utils class is managed, then it should be able to inject the managed UriInfo instance. How this (getting the Utils class managed) will be achieved depends on the implementation you are using, and it's underlying injection framework.
For instance, with Jersey (2), I could do this
public class Utils {
#Context UriInfo uriInfo;
public String test(String s) {
return s + "=" +uriInfo.getAbsolutePath().toString();
}
}
#Path("some")
public class SomeResource {
#Inject
Utils utils;
#GET
public Response getSomething() {
return Response.ok(utils.test("Hello")).build();
}
}
public class JerseyApplication extends ResourceConfig {
public JerseyApplication() {
packages("stackoverflow.jersey.test");
register(new AbstractBinder(){
#Override
protected void configure() {
bind(Utils.class).to(Utils.class);
}
});
}
}
And this works just fine
C:\>curl -v http://localhost:8080/some
Result: Hello=http://localhost:8080/some
Jersey uses HK2 for its injection, so I am able to leverage it to injection of my Utils class.
Now this is probably not the answer you're looking for (as it defeats the purpose of a static utility class), but what you are trying too just can't be done. Either way you go, whether refactoring to pass the UriInfo to your static methods, or the solution above, you will probably have a lot of refactoring to do. I'm surprised you've already created 200 methods using this functionality, before making sure one worked :/

Jersey: forbid unspecified parameters

I'm developing REST API with Jersey as JAX-RS implementation.
In every resource I explicitly define expected parameters:
#GET
#Path("/someData")
public Response getSomeData(
#QueryParam("id") final Long id,
#QueryParam("name") final String name) {
...
}
There are a number of fixed parameters, which are common for all resources (e.g. "locale").
Is there any way (I'm ok with introducing Jersey-specific dependencies) I can forbid any parameters that belong neither to method parameters nor to the common parameters?
So for example if user invokes
/api/resource/someData?id=10&locale=en - he gets the data, but if he invokes
/api/resource/someData?id=10&locale=en&fakeParam=AAA - status 400 is returned, with content stating that fakeParam is unknown parameter.
Currently second request is processed the same way as the first one, and fakeParam is simply ignored.
I think described validation will help users of my API to spot bugs earlier.

I don't know of any way to do this with JAX-RS but you could easily roll your own solution. This is a bit cumbersome but you could do something like:
#Path("/api")
public class Service {
#Context
UriInfo uriInfo;
ImmutableSet<String> commonParams = ImmutableSet.of("locale");
#GET
#Path("validate")
#Produces(MediaType.APPLICATION_JSON)
public String validate(#QueryParam("foo") String param) {
Set<String> validParams = newHashSet(commonParams);
class Local {};
for (Annotation[] annotations: Local.class.getEnclosingMethod().getParameterAnnotations()) {
for (Annotation annotation: annotations) {
if (annotation instanceof QueryParam) {
validParams.add(((QueryParam)annotation).value());
}
}
}
if (!difference(uriInfo.getQueryParameters().keySet(), validParams).isEmpty()) {
//throw an unknown parameter exception
}
return "hello";
}
And if you're using Guice or some other AOP tool with Jersey you could probably put this into an aspect s.t. you wouldn't have to add boilerplate to every method you want to validate.

JAX-RS multiple classes with the same path

With JAX-RS, is it possible to have more than one class assigned to a single path? I'm trying to do something like this:
#Path("/foo")
public class GetHandler {
#GET
public Response handleGet() { ...
}
#Path("/foo")
public class PostHandler {
#POST
#Consumes(MediaType.APPLICATION_JSON)
public Response handlePost() { ...
}
This apparently isn't allowed as I get:
com.sun.jersey.api.container.ContainerException: A root resource, class PostHandler, has a non-unique URI template /foo
I can always create one class to handle requests and then delegate to helper classes. I was hoping there was a standard way of doing so.

The JAX-RS spec doesn't forbid such a mapping. For example, Resteasy JAX-RS implementation allows for it. The feature should be jersey specific.
Regarding:
I can always create one class to handle requests and then delegate to helper classes. I was hoping there was a standard way of doing so.
Usually you have the resource classes with the same name as the path:
#Path("/foo")
public class FooResource {
#GET
#Path("/{someFooId}")
public Response handleGet() {
...
}
#POST
#Consumes(MediaType.APPLICATION_JSON)
public Response handlePost() {
...
}
}

You cannot have multiple resources mapped to the same path. I tried that few days back and landed up at similar error.
I ended up doing subpaths such as /api/contacts for one resource and /api/tags for another.
The only other long way is to create resources in multiple packages and then create different app for each.

I had the similar issue, making the class level #PATH annotation to empty string and moving the resource name to method level #PATH annotation fixed this issue.
#Path("")
public class GetHandler {
#GET
#Path("/foo")
public Response handleGet() {
// impl
}
}
#Path("")
public class PostHandler {
#POST
#Path("/foo")
#Consumes(MediaType.APPLICATION_JSON)
public Response handlePost() {
// impl
}
}