vlingo/actors tutorials. defaultLogger property needs to be true.

[ghost]

at vlingo/actors tutorial, the vlingo-actors.properties file says:

...
plugin.jdkLogger.defaultLogger = false

It throws NullPointerException. Here stack trace:

java.lang.NullPointerException
    at io.vlingo.actors.World.register(World.java:122)
    at io.vlingo.actors.plugin.logging.jdk.JDKLoggerPlugin.start(JDKLoggerPlugin.java:63)
    at io.vlingo.actors.plugin.PluginLoader.registerPlugin(PluginLoader.java:79)
    at io.vlingo.actors.plugin.PluginLoader.loadEnabledPlugins(PluginLoader.java:35)
    at io.vlingo.actors.World.<init>(World.java:270)
    at io.vlingo.actors.World.start(World.java:47)
    at io.vlingo.actors.World.start(World.java:39)
    at com.github.aleixmorgadas.vlingo.PlaygroundTest.testPlayPingPong(PlaygroundTest.java:11)

java.lang.IllegalStateException: Cannot load plugin io.vlingo.actors.plugin.logging.jdk.JDKLoggerPlugin

    at io.vlingo.actors.plugin.PluginLoader.registerPlugin(PluginLoader.java:83)
    at io.vlingo.actors.plugin.PluginLoader.loadEnabledPlugins(PluginLoader.java:35)
    at io.vlingo.actors.World.<init>(World.java:270)
    at io.vlingo.actors.World.start(World.java:47)
    at io.vlingo.actors.World.start(World.java:39)
    at com.github.aleixmorgadas.vlingo.PlaygroundTest.testPlayPingPong(PlaygroundTest.java:11)

When the value is changed to true, it works. After the researching why it happens, found the case at World.java#L122 returns null value due to keep method overrides the default logger being unable to be found by findDefault().

[VaughnVernon]

Ok, thanks. This is now corrected in the tutorial blog post. This recently changed because:

• The first logger to get registered becomes the default, so default = false didn't matter for only one logger
• Any other logger to get registered after that and is default = true takes over as default
• Now I have replaced JDK logger with an actor-based logger (async logging) but I have to bootstrap the normal JDK logger in because starting the World requires a logger, which now happens in plugin pass 1, and then during pass 2 I replace the normal JDK logger with the actor-based logger that actually reuses the pass 1 JDK logger internally :)