Singleton
Creating a singleton object to store global data
Create a class to store the singleton data and attach it to an object in the scene with 'DO NOT DESTROY ON LOAD' checked.
In your Java class, do the following:
public class Data extends Component {
    
    private int value1 = 10;
    private int value1 = 20;
    
    public int getValue1() {
        return this.value1;
    }
    
    public void setValue1(int value1) {
        this.value1 = value1;
    }
    public int getValue2() {
        return this.value2;
    }
    public void setValue2(int value2) {
        this.value2 = value2;
    }
}
In your other Java class, do the following:
public class YourClass extends Component {
    
    @Singleton
    private Data data;
    
    @Override
    public void start() {
        Console.log("Value 1: " + data.getValue1() + "\n" + "Value 2: " + data.getValue2());
    }
    @Override
    public void repeat() {
        
        if (Input.getTouch(0).isDown()) {
            
            data.setValue1(data.getValue1() + 1);
            data.setValue2(data.getValue2() + 1);
            Console.log("Value 1: " + data.getValue1() + "\n" + "Value 2: " + data.getValue2());
        }
    }
}