How to Call Data structure from other classes

I want to call data structure from another classes but i find a problem here, can you help me?

here the source code

The data structure from class SimBetWithFairRouting

public  Map<DTNHost, ArrayList<Double>> neighborsHistory;

and i will call it in this method from class NeighbourhoodSimilarity

private double countDirectSimilarity(double[][] matrixEgoNetwork, int index) {
    double sim=0;

    for (int i = 0; i < matrixEgoNetwork.length; i++) {
//here the problem
        if (matrixEgoNetwork[i][0]==this.countAggrIntStrength(*i will call it in here*) && matrixEgoNetwork[i][index]==1) {
            sim++;

        }
    }

    return sim;

}

any way i can make this work without changing the map into static form? clue : in the class SimBetWithFairRouting had replicate method, can you help me?

To access the map, you have to import that class to the class where you write the method. And to access it without creating an instance you have to make it static.

private double countDirectSimilarity(double[][] matrixEgoNetwork, int index) {
    double sim=0;

    for (int i = 0; i < matrixEgoNetwork.length; i++) {
            if (matrixEgoNetwork[i][0]==this.countAggrIntStrength(SimBetWithFairRouting.neighborsHistory) && matrixEgoNetwork[i][index]==1) {
            sim++;

        }
    }

    return sim;

}

Make your map static

public static Map<DTNHost, ArrayList<Double>> neighborsHistory;