How to display content in Base URL of Jersey Web Application?

I want to ask the basic question about Jersey Application.
Is it possible to add and display HTML content in Base URL? If it is possible, how can I implement it?

I use Jersey 2.X Application.
In the usual, I extends the ResourceConfig to implement and set the ApplicationPath as "/api". Besides, I set the resource Path as "test" in Test class and define testResp() with "GET" request.
I use maven to build service.war and deploy on local tomcat, so I can access http://localhost:8080/service/api/test to get result in browser.

But now, I want to display some HTML content in API Base URL: http://localhost:8080/service/api/
For example, I will put some introduction for this service and user can access API Base URL to read.
How can I implement it if possible? Thanks a lot!

Following is the some code example.

Jersey Application sample:

@ApplicationPath("/api")
public class WebApplication extends ResourceConfig {
    public WebApplication() {
        /**
         * register resource, load setting, ...etc
         */
    }
}

Resource sample:

@Path("test")
public class Test {

    @GET
    public Response testResp() {
        /**
         * impliment the action of http://localhost:8080/service/api/test/
         */
    }
}