How do i set up a DelayQueue's Delay

Question

I'm just starting out coding in java i'm in struggling with setting up a DelayQueue,

I wanted to have it so,

DelayQueue queue = new DelayQueue();

If (counter > 0){
queue.offer(Integer, *A custom delay*)
} Else {
queue.offer(Integer, *A different custom delay*)
}

I'm just trying to learn all the basics and ive read over the API and cant seem to grasp it.

Thanks in advance

Answer 1

The DelayQueue keeps the elements internally until a certain delay has expired. The elements must implement the interface java.util.concurrent.Delayed.

For example I have created a class DelayedTest extending Delayed interface. This will implement compareTo and getDelay() method

public class A{
    public static void main(String... args){
        DelayQueue  dq=new DelayQueue();
        DeleyedTest ob1=new DeleyedTest(10);
        DeleyedTest ob2=new DeleyedTest(5);
        DeleyedTest ob3=new DeleyedTest(15);

        dq.offer(ob1);
        dq.offer(ob2);
        dq.offer(ob3);

        Iterator itr=dq.iterator();
        while(itr.hasNext()){
            DeleyedTest dt=(DeleyedTest)itr.next();
            System.out.println(dt.deleyTime);
        }
    }
}
class DeleyedTest implements Delayed{
    public long deleyTime=0;
    DeleyedTest(long deleyTime){
        this.deleyTime=deleyTime;
    }

    @Override
    public int compareTo(Delayed ob) {
        if(this.deleyTime<((DeleyedTest)ob).deleyTime){
            return -1;
        }else if(this.deleyTime>((DeleyedTest)ob).deleyTime){
            return 1;
        }
        return 0;
    }
    @Override
    public long getDelay(TimeUnit unit) {
        return unit.convert(deleyTime-System.currentTimeMillis(),TimeUnit.NANOSECONDS); 
    }

}

Result:

5
10
15