Java Question!!!

joePC

OK thanks for the help on the last thread, but not really what im after i'll explain..

Is there a command to restart a program or go gack to the first line of code,

e.g. Unload Me in VB, can it be done in java....

Thanks loads in advance....

Thanks joePC

seamus

The best way is probably to enclose the entire contents of the main() method in a while loop. so for example:

public class MyClass {
    public static void main(String[]args) {
         while(true) {

                  //..............insert your code here.........

          }
     }
}

To loop back to the start of the while loop (ie skip the rest of the while loop) you use the 'continue' keyword.

There must be a better way to do what you're trying to do though......

joePC

Thanks Seamus, but that would cause alot of problems, there must be another way

Thanks joePC...

seamus

Indeed there must be Daniel Jackson.

What exactly is it you want to do? And post up some source code of what you've tried already.

124124

I haven't touched VB since 1997, so pardon me ignorance, does 'UNLOAD ME' mean 'close this program'?

Now, from other posts, I gather that JoePC is trying writing java applications (launched from command prompt, with java command.). If you are looking for a way to exit an application, its

System.exit(0);

Hope this helps,

124.

scojones

unload me means unload this form, me having the same meaning as 'this' in java.

joePC

Thanks for the help, got it all sorted, I put the contents of my main into a method and can access the method anytime using mathod();

Thanks joePC

martinoc

use the following:



Runtime.exec("java mypackage.MyMainClass");

and then exit the program.


The above executes a new process (at os level).
If the above does not work then the string probably should be fully qualified so should read:

Runtime.exec("c:\j2re4.1.2\bin\java mypackage.MyMainClass");

Replace the path with the location of your own jre.

Hobbes

Originally posted by martinoc
use the following:



Runtime.exec("java mypackage.MyMainClass");

and then exit the program.

Why?

Why not just javaw instead of java? Or for that matter why Runtime.exe() ?

martinoc

You can use javaw if you want. Javaw is just a windows extention to the jre. It's irrelevent.

The point of using Runtime.exec(String command) is that a clean process is started.
The program in question can in effect spawn itself before exiting. Exactly what the original poster wanted.

I know its a horrible hack and is os dependant, but it can solve the posters problem.

Hobbes

or he could build his app as a class then have main call that class and have it recreate the class to go back to the start.

martinoc

That was already suggested (kinda) above and he rejected it and asked if there was any other way. I've just suggested an alternative.

124124

Originally posted by sjones
unload me means unload this form, me having the same meaning as 'this' in java.

Well, not to be rude or anything, but from the questions that JoePc is posting (and more so from his solutions), I honestly think he should get his basics right - things like what’s a class, and what and why a method, process etc. With out correct basics, java is an awfully difficult language to master.

Good luck mate!

124.

Hobbes

Well seamus is correct but better to do this way.

public class MyClass {
     private boolean mWorkComplete = true;

    // This is the method that runs by default. 
    public static void main(String[]args) {
          
          MyClass m = new MyClass();
          
          do {
                  m.doMyStuff();
          } while(m.isStillWorking());
     }

      public boolean isStillWorking() {
            return mWorkComplete;
      }

      public void doMyStuff() { 
            mWorkComplete = false;
           // Put your code here. 
           // When the work is done set mWorkComplete to true.
      }
}

This means at a later point you can seperate the main () to another class or create MyClass in another class/application and run it there.

Although a thread would be better.