How to pass an argument to ScheduledThreadPoolExecutor?

Question

How would i pass an argument to the ScheduledThreadPoolExecutor?

I have the following code. You will notice that i have declared a variable 'num' and it is passed as an argument to exampleFunction(). exampleFunction contains a ScheduledThreadPoolExecutor. I want to be able to use the variable 'num' inside public void run(). Is there any way i can do that?

     class Test {
     ...
     int num;
     exampleFunction(num);
     ...

     public void exampleFunction(num) {
         ScheduledThreadPoolExecutor exec = new ScheduledThreadPoolExecutor(1);
         exec.schedule(new Runnable() {
             public void run() {
                 ...do something here...
                 ...something with 'num' here...
                 ...i get an error when i try to use 'num' here
             }
         }, 10, TimeUnit.SECONDS);
     }

}

Answer 1

Did you try changing exampleFunction(num) as exampleFunction(final int num)? Since run method is in an inner class all external bindings need to be final.

public void exampleFunction(final int num) { // final int here
     ScheduledThreadPoolExecutor exec = new ScheduledThreadPoolExecutor(1);
     exec.schedule(new Runnable() {
         public void run() {
             ...do something here...
             ...something with 'num' here...
             ...i get an error when i try to use 'num' here
         }
     }, 10, TimeUnit.SECONDS);
 }

Answer 2

Either make num final or static (or accessible from a static method), or else create your own Runnable.

class MyRunnable implements Runnable {
    int num;

    public MyRunnable(int num) {
        this.num = num;
    }

    public void run() { ... }
}

Answer 3

declare you variable num final and you will be able to use it inside the Run() method.

Write this instead

final int num;