Take for example, a fashion store business that maintains a number of key accounts, the designer houses. The main entry point into the REST style interface could be separated out into constituent parts. The following code shows two JAX-RS resource classes FashionStore and DesignerHouse:

@Path("/")
public class FashionStore {
  @Path("/designers/{id}")
  public DesignerHouse getDesigner( @PathParam("id") int id ) 
  {
    DesignerHouse house = houseData.findById(id)return house;
  }
}

public class DesignerHouse {
  @GET
  public String getDetails() { /*...*/ }
  
  @Path("/principal")
  public String getPrincipal() { /*...*/ }
}

The root URI pattern @Path("/") matches the class FashionStore, and therefore this master resource behaves like the root of the entire REST style interface. This class may well have other responsibilities in true business applications.

Given an incoming request for a listed designer HTTP GET request, the FashionStore delegates to a subresource through the method getDesigner(). The method is annotated with @Path("/designers/{id}") and it returns a subresource object DesignerHouse.

JAX-RS runtime provider will see the DesignerHouse object that was returned and then proceed to process the remaining parts of incoming URI with that object. In the specification, this is called Subresource Resolution by Location. JAX-RS then proceeds to process HTTP GET request and invokes the getDetails() method and after this call completes, the process is complete.

The alternative subresource resolution strategy makes the code part of the parent resource. The JAX-RS resource processes the HTTP request directly. This is known as the Subresource Resolution by Direct Method.

Let's add one more method to our fashion store example that will clarify resolution by direct method. There is a requirement for certain staff to get cashier information in order to deal with specific customer requests such returns of garment, collection, alterations, and other usual requests. All such staff must work with an authorized cashier information stamp for these daily tasks and audit.

The following code shows the additional subresource method:

@Path("/")
public class FashionStore {
  @GET
  @Path("/staff/{domain}/{staffCode}")
  public String getCashierInfo( 
    @PathParam("staffCode") String staffCode,
    @PathParam("domain") String domain ) {
      return cashierManagerService.findByCodeAndDomain(
        staffCode,domain)
  }
}

The HTTP GET request /staff/2042/summerbys will cause the JAX-RS runtime to activate the method getCashierInfo().