debugging simple java files.

[Mandar Khire]

I use eclipse juno & netbeans 7.2 for this:-
I use simple code as below:-

package abc;
public class helloworld {
    public static void main(String[] args) {
       System.out.println("Hello World");    
    }
}

aim:- try to understand whats really happens behind before output seen on screen. I start with simple one...want to go for harder...

scenario:- As i tried in eclipse i can see in lots of variable sets before print statement execute...all variables for class.Some are as follows:-
defaultUncaughtExceptionHandler,EMPTY_STACK_TRACE,MAX_PRIORITY,MIN_PRIORITY,NORM_PRIORITY,SUBCLASS_IMPLEMENTATION_PERMISSION,threadInitNumber,threadSeqNumber,blocker,blockerLock,
contextClassLoader,daemon,eetop,group,inheritableThreadLocals,inheritedAccessControlContext,name,nativeParkEventPointer,parkBlocker,priority,single_step,stackSize,stillborn,target,threadLocals,threadQ,l
threadStatus,tid,uncaughtExceptionHandler...etc many more

From netbeans debugging i got info that (when all lines set breakpoint)
I got

Listening on javadebug
User program running
LineBreakpoint helloworld.java : 6 successfully submitted.
LineBreakpoint helloworld.java : 5 successfully submitted.
MethodBreakpoint [abc.helloworld].main '([Ljava/lang/String;)V' successfully submitted.
Class breakpoint hit for class abc.helloworld.
Thread main stopped at Class.java.getDeclaredMethods0.
User program running
Thread main stopped at System.java:329.
User program running
.
.
Thread main stopped at Thread.java:743.
User program running
User program finished

Almost 884 lines debug output.
& 22 java files use like Class.java,System.java,Collections.java... & helloworld.java which is source.
Question is:-
1. For simple class which use is also simple...really needs so much variables setting which shown in eclipse debugging activity in variables.
2. For more deep debugging should i put more breakpoints in java's .java files all lines? Some files contain more than 2000 lines. What is a best practice for put breakpoints?

[William P O'Sullivan]

It sounds like you are not just debugging your simple Class, but java itself!

Why would you want to do that?

WP

[Mandar Khire]

Thanks William P O'Sullivan,

...but java itself!
Why would you want to do that?

because curiosity, interest...
i am not trying to solve java's bug...but want to see how particular code behave when we called it by directly or indirectly.