Communicating Variable State Between Classes Java

Question

I have two classes in a package and I want to know how I can pass the state of a boolean from one class to the other. Basically in class 1 the user has an option to either load a file or to start the application without loading a file. If they load a file I need class 2 to check if the boolean in class 1 is true. I'm confused because the way I understand it is that the instance of class 1 is not created until class 2's " clickButton() " method is called. So I thought if I create the instance of the class after clickButton is called, then I would get the updated boolean statement. But it's not working...I'm always getting false. A simplified look of my classes are below:

CLASS 1:

public class Class1 {

public boolean isLoaded = false;

public void loadFile(){

if (fileLoaded == true){
isLoaded = true;
}

}

public boolean checkIfLoaded(){
return isLoaded;
} 

CLASS 2:

public class Class2 {

public void clickButton(ActionEvent e){

Class1 instance = new Class1();
system.out.println(instance.checkIfLoaded());

}
}

Is there a good way to communicate a boolean change between two classes after compile time?

Answer 1

Creating a new class will not save the value of the variable. There are several ways to solve this: 1) Pass ClassA to the ClassB constructor

public Class2 (Class1 class1) {}

but I think this is not very convenient.

2) You can also declare checkIfLoaded and isLoaded static and just execute ClassA.checkIfLoaded ();