I have a Java project that I recently inherited and admittedly my Java skills are very rusty. In this code there are several public variables. Moving forward we would like to change these to private with getters and setters. The problem lies in that there are many pieces of legacy code still in use by others, that I do not have access to, that access these public variables directly. We are looking to add in an adapter layer of code so that their interface does not actually change, but we are stuck on how to update the variables. Is there a way to detect when a public variables value has changed? I was hoping there might be some type of listener implementation to handle this but I am having no luck right now. Any suggestions?