How to Debug Java Code with AI

Ask a coding agent to solve a failure in a large Java application and it will often give you a confident answer that turns out to be wrong. That is not a limit on the model. It is a limit on what the model can see, because the hardest problems live in runtime state, not in the source code.

Give the agent the runtime context and the guesswork stops.

This demo shows Claude working from an Undo recording alone, with no access to the source. It reads the console output, sets an exception breakpoint, inspects the stack, requests a watchpoint, and runs the program backwards to the exact instruction and thread that modified the list. The result is a full explanation of what actually happened, backed by evidence.