Java: using object from class in another class

Question

I have two different files. In the file below I create a new object with an attribute and I create a method to retrieve that attribute.

public class Journey
{
    public double singleCost;

    public void setSingleCost(double cost) {
        singleCost = cost;
    }

    public double getSingleCost() {
        return singleCost;
    }

    public static void main (String[] args) {
        Journey leicester_loughborough = new Journey();
        leicester_loughborough.setSingleCost(2.5);

        Journey leicester_nottingham = new Journey();
        leicester_nottingham.setSingleCost(3.5);
    }
}

In a separate file, I would like to print out that object's attribute. I'm not sure how to do that though. The following doesn't seem to work.

public class JourneyMethods
{    
    public static void main (String[] args) {
        System.out.println(leicester_loughborough.getSingleCost());
    }
}

I would appreciate any help, thanks.

Answer 1

You are thinking about this too much as main methods.

Your JourneyMethods main method knows nothing about the Journey class unless you tell it. JourneyMethods will be able to interact with a Journey instance if you create a reference to a Journey.