brooklyn-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From aledsage <...@git.apache.org>
Subject [GitHub] brooklyn-server pull request #408: Use actual config key if available in DSL
Date Mon, 07 Nov 2016 09:35:15 GMT
Github user aledsage commented on a diff in the pull request:

    https://github.com/apache/brooklyn-server/pull/408#discussion_r86738337
  
    --- Diff: camp/camp-brooklyn/src/main/java/org/apache/brooklyn/camp/brooklyn/spi/dsl/methods/DslComponent.java
---
    @@ -144,7 +147,7 @@ public Entity call() throws Exception {
             
             protected Maybe<Entity> callImpl(boolean immediate) throws Exception {
                 Maybe<Entity> entityMaybe = getEntity(immediate);
    -            if (immediate && entityMaybe.isAbsent()) {
    +            if (immediate && entityMaybe.isAbsentOrNull()) {
    --- End diff --
    
    Is this to avoid the `NullPointerException` you saw before https://github.com/apache/brooklyn-server/pull/404
was merged? I wondered about this.
    
    The problem with returning `Maybe.of(null)` if the entity can't be resolved is that it's
different semantics from `deferredSupplier.get()`. For the latter, it would throw `NoSuchElementException`
with a nice message explaining it. Now this will just return a null.
    
    The intent is that `getImmediately()` will either return `absent()` if it can't be resolved
immediately, or will return immediately exactly the same value as `get()` would.


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---

Mime
View raw message