Most Java developers these days deal with Spring on a regular basis and there are lots of us out there that have become familiar with its abilities as well as its limitations. I recently came across a problem that I hadn’t hit before: introducing the ability to rewire a bean’s internals based on configuration introduced at runtime. This is valuable for simple configuration changes or perhaps swapping out something like a Strategy or Factory class, rather than rebuilding of a complex part of the application context. I was able to find some notes about how to do this, but I thought that some might find my notes and code samples useful, especially since I can confirm this technique works on versions of Spring back to 1.2.6. Unfortunately, not all of us are lucky enough to be on the latest and greatest of every library.