Java™ Application Development on Linux - Dator

5.9 The Java Debugger151Example 5.17 index.html used in jdb sessionRedHat Linux LaptopRedHat Linux LaptopYou have contacted Michael Schwarz's RedHat Linux Laptop.You would probably rathersee his permanent Webpage since this server goes up and down all the time, whatwith it being on a laptop.Example 5.18 is an actual transcript of a real jdb session. It is annotatedwith explanatory comments. Our goal here is to get you going. The best wayto learn jdb, or indeed any of these tools, is to use them.Obviously, this little session has merely scratched the surface of the Javadebugger. You can debug multithreaded applications with commands that cansuspend and resume individual threads, list the running threads, switch your“executable view” between threads, and so forth. You can trace method calls.You can monitor variables. You can execute expressions (including assignmentexpressions, allowing you to force variables to certain values). You can browseclasses. You can dump all local variables with a single command. The debuggeris quite capable, if a bit limited in user interface. 23 Learn it. Play with it. Stepthrough your favorite Java program with it.23. As you know, we do not automatically like IDEs and GUI development tools (see Section5.2). A debugger is an exception to that rule. When debugging, a well designed UI witha code pane, a stack pane, a data viewer, a class browser, a thread selection pane, and so on isenormously helpful. You need to be able to see all these elements nearly simultaneously; youneed to see the whole system as it runs. The command-line debugger makes everything you needavailable, but with a traditional “glass-teletype” UI that is quite awkward. By all means, learnthe CLI debugger, but then find a good Java debugger with a windowed UI of some kind. Itis hard to say which compiler UI is the best, but I think we can safely say the command-linedebugger UI is the worst! You should know it as a last resort, but use it as a last resort!