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Cannot instantiate the type Pair although not abstract

Trying to write an iterator that returns a Pair:
Part of my PairIterator

public Pair next() {
this.counter ++;
Pair p = new Pair(this.l.get(counter - 1), this.l.get(counter));
//error occurs here

}

public class Pair<E> {
private E e1;
private E e2;

public Pair(E e1, E e2) {
this.e1 = e1;
this.e2 = e2;
}
public E first() {
return this.e1;
}
public E second() {
return this.e2;
}
}


getting

Cannot instantiate the type Pair

... although Pair is not an abstract class/interface. Why is this happening?

2 Answers
2

Make sure to import the correct class to initialize your pair object.

import org.apache.commons.math3.util.Pair;


Concrete Class -> Can directly create object.

This gives an error:

import org.apache.commons.lang3.tuple.Pair;


Its an abstract class, so you can't create the object directly.

Most likely because you didn't add generic type parameters to Pair.

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