How to intercept & debug all Java HTTPS

Java and the JVM more generally are widely used for services everywhere, but often challenging to debug and manually test, particularly in complicated microservice architectures. HTTP requests and responses are the core of interactions between these services, and with their external APIs, but they’re also often invisible and inaccessible. It’s hard to examine all outgoing requests, simulate unusual responses & errors in a running system, or mock dependencies during manual testing & prototyping.