Problem:

When we develop a REST API for our business, we may need to protect some of our APIs using API key or some kind of security mechanism. This can be achieved using Container Request Filter option available in Jersey framework. But in some cases we may need to ignore this validation or bypass this filter and allow our API call. For example, we can consider user CRUD REST API. /users is our main entry point to reach our REST API. Here, registering a user doesn’t require any kind of security check, whereas, when getting the user information, we need some kind of security restrictions. How can this be achieved using the Jersey framework?

Solution:

To achieve the above use case, we can use the @NameBinding annotation, which is available in Jersey. Follow the 3 simple steps to get that working.

• Introduce an interface with the @NameBinding annotation.
• Introduce a Container Request filter with our custom annotation.
• Use our annotation in our API (to require the security check).

@NameBinding annotation

@NameBinding
@Retention(RetentionPolicy.RUNTIME)
public @interface ApiKeyProtected {}

Filter with annotation

@ApiKeyProtected
public class ApiKeyCheckFilter implements ContainerRequestFilter {
    private static final Logger logger = LogManager.getLogger(ApiKeyCheckFilter.class);

    @Override
    public void filter(ContainerRequestContext requestContext) throws IOException {
        logger.info("Requested Path: {}", requestContext.getUriInfo().getPath());

        final String apiKeyValue = requestContext.getHeaderString("X-API-KEY");
        if (apiKeyValue == null || apiKeyValue.isEmpty()) {
            requestContext.abortWith(Response.status(
                    Response.Status.UNAUTHORIZED)
                    .entity("X-API-KEY is missing in the header")
                    .build());
        }
    }
}

Resource method with annotation

@GET
@Path("{id}")
@ApiKeyProtected
Response get(@PathParam("id") String id);

@POST
@Consumes(MediaType.APPLICATION_JSON)
Response create(User user);

We are done with our implementation. When you try to access the GET API, it will ask you to pass the X-API-KEY header value along with your header parameter. whereas when you access the POST API, it won’t ask you for any header.

Cool, right?

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