Build route name correctly

implementation/rest/src/main/java/io/smallrye/opentelemetry/implementation/rest/OpenTelemetryServerFilter.java

@@ -183,20 +183,20 @@ public String getTarget(final ContainerRequestContext request) {
         public String getRoute(final ContainerRequestContext request) {
             try {
                 // This can throw an IllegalArgumentException when determining the route for a subresource
-                Class<?> resourceClass = (Class<?>) request.getProperty("rest.resource.class");
+                Class<?> resource = (Class<?>) request.getProperty("rest.resource.class");
                 Method method = (Method) request.getProperty("rest.resource.method");
 
-                UriBuilder template = UriBuilder.fromResource(resourceClass);
+                UriBuilder uriBuilder = UriBuilder.newInstance();
                 String contextRoot = request.getUriInfo().getBaseUri().getPath();
                 if (contextRoot != null) {
-                    template.path(contextRoot);
+                    uriBuilder.path(contextRoot);
                 }
-
+                uriBuilder.path(resource);
                 if (method.isAnnotationPresent(Path.class)) {
-                    template.path(method);
+                    uriBuilder.path(method);
                 }
 
-                return template.toTemplate();
+                return uriBuilder.toTemplate();
             } catch (IllegalArgumentException e) {
                 return null;
             }

testsuite/extra/src/test/java/io/smallrye/opentelemetry/test/rest/ContextRootTest.java

@@ -0,0 +1,71 @@
+package io.smallrye.opentelemetry.test.rest;
+
+import static io.opentelemetry.api.trace.SpanKind.SERVER;
+import static io.opentelemetry.semconv.trace.attributes.SemanticAttributes.HTTP_ROUTE;
+import static io.restassured.RestAssured.given;
+import static java.net.HttpURLConnection.HTTP_OK;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.net.URL;
+import java.util.List;
+
+import jakarta.inject.Inject;
+import jakarta.ws.rs.ApplicationPath;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.core.Application;
+import jakarta.ws.rs.core.Response;
+
+import org.jboss.arquillian.container.test.api.Deployment;
+import org.jboss.arquillian.junit5.ArquillianExtension;
+import org.jboss.arquillian.test.api.ArquillianResource;
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.spec.WebArchive;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import io.opentelemetry.sdk.trace.data.SpanData;
+import io.smallrye.opentelemetry.test.InMemorySpanExporter;
+
+@ExtendWith(ArquillianExtension.class)
+class ContextRootTest {
+    @Deployment
+    public static WebArchive createDeployment() {
+        return ShrinkWrap.create(WebArchive.class);
+    }
+
+    @ArquillianResource
+    URL url;
+    @Inject
+    InMemorySpanExporter spanExporter;
+
+    @BeforeEach
+    void setUp() {
+        spanExporter.reset();
+    }
+
+    @Test
+    void route() {
+        given().get("/application/resource/span").then().statusCode(HTTP_OK);
+
+        List<SpanData> spanItems = spanExporter.getFinishedSpanItems(1);
+        assertEquals(1, spanItems.size());
+        assertEquals(SERVER, spanItems.get(0).getKind());
+        assertEquals(url.getPath() + "application/resource/span", spanItems.get(0).getAttributes().get(HTTP_ROUTE));
+    }
+
+    @ApplicationPath("/application")
+    public static class RestApplication extends Application {
+
+    }
+
+    @Path("/resource")
+    public static class Resource {
+        @GET
+        @Path("/span")
+        public Response span() {
+            return Response.ok().build();
+        }
+    }
+}