fix: better graphql response type for native (#43)

Co-authored-by: TakahashiNg <83152264+TakahashiNguyen@users.noreply.github.com>
Reviewed-on: #43

gateway-service/src/main/java/com/drinkool/controller/EateryController.java

@@ -10,6 +10,9 @@ import jakarta.ws.rs.core.Context;
 import jakarta.ws.rs.core.HttpHeaders;
 import jakarta.ws.rs.core.Response;
 import org.eclipse.microprofile.config.inject.ConfigProperty;
+import jakarta.inject.Inject;
+import jakarta.json.bind.Jsonb;
+import jakarta.ws.rs.core.MediaType;
 
 @Path("/api/eatery")
 public class EateryController {
@@ -17,6 +20,9 @@ public class EateryController {
 	@ConfigProperty(name = "quarkus.smallrye-graphql-client.eatery.url")
 	String eateryUrl;
 
+	@Inject
+    Jsonb jsonb;
+
 	@POST
 	@Path("/graphql")
 	public Response forward(
@@ -45,10 +51,12 @@ public class EateryController {
 			);
 
 			if (response.hasError()) {
-				return Response.status(400).entity(response.getErrors()).build();
+				return Response.status(400).entity(jsonb.toJson(response.getErrors())).build();
 			}
 
-			return Response.ok(response.getData()).build();
+			return Response.ok(jsonb.toJson(response.getData()))
+                           .type(MediaType.APPLICATION_JSON)
+                           .build();
 		} catch (Exception e) {
 			e.printStackTrace();
 			return Response.serverError()