> And I certainly don't need the levels of abstraction that design patterns or Haskell typeclasses demand. I think it's fair to say that AbstractSingletonProxy

> And I certainly don't need the levels of abstraction that design patterns or Haskell typeclasses demand. I think it's fair to say that AbstractSingletonProxyFactoryBean[0] is something of an abomination, but it's important to avoid throwing the baby out with the bathwater. Some of the Go4 patterns like Command, Observer, Visitor, and Iterator are literally all over the place and you have to actively go out of your way to avoid writing them. Likewise, Haskell type classes aren't something you're supposed to be implementing yourself all over the place in your application. They're very high bang-for-buck things you implement in libraries. The equivalent to implementing iterators for your collections, or AutoCloseable on resource-like java classes. 0. https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/aop/framework/AbstractSingletonProxyFactoryBean.html https://docs.spring.io/spring-framework/docs/current/javadoc...