Boost Your Productivity: Advanced IDEA Debugging Techniques You Need

Introduction

Effective debugging with IntelliJ IDEA can greatly improve work efficiency. This article presents several often‑overlooked debugging tricks useful in daily development.

Main Techniques

2.1 Debug without pausing

Normally a breakpoint stops the current thread, which can be disruptive in shared environments. Instead, you can directly observe variable values, forcibly change them, or view the call stack (similar to Arthas trace) without pausing execution.

2.2 Quick evaluate expression

Use the Evaluate Expression dialog (Option + F8) to run arbitrary expressions on the fly. Shortcut keys (Alt + D, Option + F9, Option + Command + F8) make this process fast.

2.3 Time‑travel debugging (drop frame)

When you need to step back to a previous state, use the drop‑frame feature to rewind execution to an earlier point.

2.4 Debug a single loop condition

If a loop runs many times but you only care about a specific iteration (e.g., the 99th), set a breakpoint on that iteration only, avoiding unnecessary stops.

2.5 Find who assigned a variable

To discover which code path assigned a value to a variable, place a breakpoint on the field itself; the debugger will stop whenever the variable is written.

2.6 Locate the actual method implementation

When many classes implement an interface, set a breakpoint on the interface method; the debugger will stop at the concrete implementation that is invoked (note this may slow down debugging).

2.7 Run to cursor

Instead of setting a breakpoint on a later line, use "Run to Cursor" (Option + F9) to continue execution directly to the desired line.

2.8 Global exception breakpoint

Enable a global exception breakpoint to automatically pause execution at the point where any uncaught exception occurs.