Learn about the observer pattern using modern Java: What it is, specializations, common naming conventions, and more!
The Observer Pattern, or the Publish-Subscribe (Pub-Sub) Pattern, is a classic design pattern codified by the Gang of Four (GoF) Design Patterns book in 1994 (pg. 293-313). Although this pattern has quite a long and storied history, it is still applicable in a wide range of contexts and scenarios, and has even become an integral part in the Standard Java Library. While there are numerous useful articles on the topic of the Observer Pattern, and its implementation in Java, many focus on the strict implementation of the pattern in Java, rather than on the idiosyncrasies and common issues developers using the Observer Pattern in Java will experience.