Java's ServiceLoader has two well-known limitations: it requires a no-arg constructor and provides no built-in selection mechanism. This post presents a provider factory pattern that addresses both. Instead of loading the service directly, you load a lightweight factory (ServiceProvider<S>) that carries an ID, a priority, and a supports() check. The real service is constructed inside create() with whatever constructor it needs. A generic ServiceRegistry loads all providers once into an immutable list sorted by priority, then exposes get(id, cfg) and getDefault(cfg) for selection. Caching is added as a decorator using ConcurrentHashMap, lifecycle reuses AutoCloseable, and cross-cutting concerns attach via a UnaryOperator post-processor. The pattern requires no dependencies beyond the JDK, works on both classpath and module path, and avoids dynamic proxies — making it GraalVM native-image friendly.
