如何从另一个java类访问和更新变量？

public class MyClass {
    private int myVariable;

    public int getMyVariable() {
        return myVariable;
    }

    public void setMyVariable(int value) {
        myVariable = value;
    }
}

MyClass myObject = new MyClass();
myObject.setMyVariable(10);
int value = myObject.getMyVariable();

public class MyClass {
    private int myVariable;

    public MyClass(int value) {
        myVariable = value;
    }

    public int getMyVariable() {
        return myVariable;
    }
}

MyClass myObject = new MyClass(10);
int value = myObject.getMyVariable();

public class MyClass {
    public static int myVariable;

    public static int getMyVariable() {
        return myVariable;
    }

    public static void setMyVariable(int value) {
        myVariable = value;
    }
}

MyClass.setMyVariable(10);
int value = MyClass.getMyVariable();