Error when trying to step into my code using F7 in NetBeans v8.0.2

[lordbyron]

I am writing a program for a self taught Java class. The program uses a class I wrote for a previous assignment. The program is a variation of Blackjack, but instead of cards it uses two six sided dice. The previous class is called Die.class and the new program is called TwentyOne.class. When I press F7 to step into the code I get an error message that says: Source path java\lang\Boolean not found. The reason is likely no open project with this source file. When I press F7 the second time I get the same message, but the path is: sun\misc\launcher.java, and the third time I press F7 the path is changed to: twentyone\TwentyOne.java.

Can someone shed some light on why this is happening? I need to step through the code to work out some problems with my code. http://www.java-forums.org/images/smilies/skype/@.gif

I have also tried running the program with JGrasp v 2.0.1_01. I get a return code of 0, but nothing happens. JGrasp doesn't have step through option.

Thanks in advance for any help.

Lord Byron

[jim829]

I use Eclipse as my IDE but I think I know what the problem is. You probably don't have the source code to the JDK classes so you can't step into the java.lang.Boolean class or other classes. Does pressing F7 continuously eventually get you back to your own code? If so, that should be sufficient since I doubt the internals of the JDK class libraries are where your coding problems exist.

Regards,
Jim

[DarrylBurke]

Moved from New to Java to NetBeans

db

[gimbal2]

The main problem here is to learn to not to rely only on F7, which is "step into". Debugging is a dance of sometimes taking a "step over" and other times doing a "step into". You want to step over methods of standard JDK classes, its only your own code you're interested in.

[DarrylBurke]

You want to step over methods of standard JDK classes, ...

There's a setting for that (Tools -> Options -> Java -> Java Debugger -> Step Filters)

db

[gimbal2]

Now I wonder if Eclipse has something similar, quite useful.

EDIT: yes it does.

window -> preferences -> java -> debug -> step filtering

[jim829]

window -> preferences -> java -> debug -> step filtering

Interesting how when helping an OP, we end up helping ourselves. Didn't know about this either. Now I don't have to think about it (I just need to remember why I now can't step into the JDK).

Regards,
Jim

[gimbal2]

I find the "filter simple getters/setters" checkboxes the most useful to be honest. I mean normally when you have code like this:

doSomeEpicThing(object.getProperty1(), object.getProperty2());

If you'd want to step into that you would first step into getPropery2(), then into getProperty1() and finally into doSomeEpicThing(). But now I can make the debugger simply skip the getProperty1() and getProperty2() calls without having to set another breakpoint inside doSomeEpicThing().

Its the small things that end up being the biggest joys.