Studio: If It Ain't Broke, Add a Breakpoint!
The purpose of this studio is to expand your current debugging strategies. First, as a group, you will discuss your current debugging strategies. Next, you will explore the debugger tools addressed in this chapter.
This studio will use a previous studio assignment to explore IntelliJ’s Debugger.
On your machine, open up your copy of
java-web-dev-projects in IntelliJ and navigate to the project for the interfaces studio.
Part One: Pre-Debugger Debugging
Share with the group one error you encountered when working on your version of the interfaces studio. This could be the result of a typo or a logical error.
- What was the error?
- How did you solve this error?
- What strategies and tools have you been using so far to debug your code?
- Could one of the debugging tools help you when addressing this error?
Part Two: Debugger Debugging
Now, check out the
debugging branch of the studio repo.
Review the code and then practice using IntelliJ’s debugging tools.
To get started, try the following:
- Add a few breakpoints inside
Main.java. Make a note of where you expect the program to break in its execution.
cd.nameas a Watch expression in the Variables Pane of the Debugger.
- Add a breakpoint inside some of the methods in
BaseDisc.java. Anticipate what you expect to see as the last line in the Variables Pane when the debugger stops.
Part Three: More Debugger Debugging
Take your debugging skills one step further by answering these questions.
- When would use a Watch expression? If you run the app and it’s already functioning, what shows up there?
- Would a conditional breakpoint make sense to use in the context of this app? Try adding a conditional breakpoint and then run your app.
- What does the Frames Pane tell you as you step through your code?
dvd.aNameas a Watch expression and add a breakpoint. Can you explain the output in the Variables Pane?
Part Four: Debugging Beyond This Studio
Once you have worked through the studio’s codebase, open up a piece of code you have been struggling with. In what ways, could the debugging tools help you figure out what is going on with the code?