I'm the creator of PF4J (https://github.com/pf4j/pf4j) - a plugin framework for adding extensibility to Java applications, used by companies worldwide (https://github.com/pf4j/pf4j#trusted-by).

After years of GitHub discussions, I kept seeing three recurring patterns everyone rebuilds:

1. Service injection - custom PluginFactory boilerplate to wire platform services (Issue #319 is typical: https://github.com/pf4j/pf4j/issues/319)

2. Plugin communication - everyone builds their own EventBus

3. Configuration - no standard approach for plugin-scoped settings

Hit these myself building a JavaFX app. PF4J handled loading, but then 30+ lines of factory code just to inject services.

Built pf4j-plus to standardize this layer:

BEFORE - custom factory everywhere:

    public class MyPluginFactory extends DefaultPluginFactory {
        @Override
        public Plugin create(PluginWrapper wrapper) {
            Plugin plugin = super.create(wrapper);
            if (plugin instanceof MyPlugin) {
                ((MyPlugin) plugin).setGreetingService(App.getGreetingService());
                ((MyPlugin) plugin).setEventBus(App.getEventBus());
            }
            return plugin;
        }
    }

AFTER - declare once:

    PluginManager pm = PlusPluginManagerBuilder.create()
        .serviceRegistry(r -> {
            r.register(GreetingService.class, new DefaultGreetingService());
            r.register(EventBus.class, new DefaultEventBus());
        })
        .build();

Plugins get ServiceRegistryAware, extensions use @Inject.

What it provides:

- ServiceRegistry - shared services for plugins

- EventBus - decoupled communication

- ConfigService - plugin-scoped configuration

Not a DI container replacement. Just standardizes the platform layer you'd build anyway. Especially useful outside Spring (desktop apps, CLI tools, embedded systems).

Early stage - using it in my own projects. Looking for feedback on what platform services are missing.

Repo: https://github.com/pf4j/pf4j-plus

Blog post: https://dev.to/decebals/why-i-built-pf4j-plus-1hl1