Comments on: How can we bypass System.exit from executing? Can anyone help me with the question

By: kinshu22

kinshu22 — Thu, 23 Aug 2012 17:18:19 +0000

I tried the below thing using SecurityManagerI tried the below thing using SecurityManager
public class t1{

static{
SecurityManager sm=new SecurityManager(){
public void checkExit(int exitCode){
System.out.println(“Good Bye”); /* Another way is to throw SecurityException over here. Then the finally block will execute but an exception will be thrown after that*/

}/*Overriding println method so that it will print false */
};
System.setSecurityManager(sm);
}
public static void main(String args[]){
try{
System.out.println(“Welcome”);
System.exit(0);
}
finally{
System.out.println(“Good Bye”);
}
}
}

By: kinshu22

kinshu22 — Thu, 23 Aug 2012 17:16:32 +0000

I tried in this way using SecurityManagerpublic class t1{static{SecurityManager sm=new SecurityManager(){public void checkExit(int exitCode){System.out.println(“Good Bye”); /* Another way is to throw SecurityException over here. Then the finally block will execute but an exception will be thrown after that*/}/*Overriding println method so that it will print false */};System.setSecurityManager(sm);}public static void main(String args[]){try{System.out.println(“Welcome”);System.exit(0);}finally{System.out.println(“Good Bye”);}}}

By: carlosdl

carlosdl — Thu, 23 Aug 2012 16:07:15 +0000

I mentioned that because there is a Runtime method you can use to “intercept” the exit execution, from which you could do something before the VM actually goes down.

By: carlosdl

carlosdl — Thu, 23 Aug 2012 16:00:30 +0000

Is it really a requirement that the finally block be executed ?

How about doing something else but printing the desired text ?

Also, can you post what you tried with SecurityManager ?

By: kinshu22

kinshu22 — Thu, 23 Aug 2012 15:21:00 +0000

Yes. But you can add your own method or static block so that finally can run even after System.exit is called.

By: carlosdl

carlosdl — Thu, 23 Aug 2012 15:09:39 +0000

So, you have to “Re write the ~~below~~ program”, but you can’t modify the main method, and the only method the program has is the “main” one. Is that right ?

By: TomLiotta

TomLiotta — Thu, 23 Aug 2012 06:46:28 +0000

Ah. Okay, that makes more sense. Or at least it doesn’t add a possible distraction.However, you should understand first that we don’t answer interview (nor homework) questions. We can help guide the search for answers, usually by suggesting ideas or references that must be researched by the questioner. That ensures that future readers will also do their own research.Understood?Tom

By: kinshu22

kinshu22 — Thu, 23 Aug 2012 06:13:04 +0000

Sorry. That was typo.. Corrected it.. I want to execute finally bock even after System.exit.

By: kinshu22

kinshu22 — Thu, 23 Aug 2012 06:10:41 +0000

Hi Tom.. Both the things are related. If you can tell me how can i bypass System.exit then by using it I can change the above program and I can print the expected output. Currently my program wont print “Good Bye” because of the use of System.exit

By: TomLiotta

TomLiotta — Thu, 23 Aug 2012 06:08:41 +0000

Was that a typo where you wrote “Good Byye”? Maybe that’s what confused me. It looked like you had some specific output that was different by adding an extra “y” from what was available in the code. — Tom