Question

in my GUI i have the

@Override
public void actionPerformed(ActionEvent ae) { 
state = new JComboBox(EnumStates.values());
state =(JComboBox)ae.getSource()
state.getSelectedItem() //this returns what I want 

then I have object of some other class like that uses the EnumStates

CallmeClass obj;

and when I try to set the state of the enum with the result of the JComboBox like this

  obj.setState(state.getSelectedItem());

I get compile error

1. required state but found object

So my question is is there a way to make the setState take as argument state.getSelectedItem() withouth changing the return type of the method setState() or re declaring the enums in the gui. Thanks.

Answer 1

I’m guessing your declaration for setState is seomthing like this:

public void setState(State state){
    ...
}

The problem is that JComboBox is untyped (at least it was that way until Java7). So getSelectedItem() always returns an object that needs to be casted to your type. So you can do the cast when you’re getting the item:

obj.setState((State)state.getSelectedItem());

Or you can change your method declaration to object and do your cast there:

public void setState(Object state){
    if(state instanceof State){
        State realState = (State)state;
        ...
    }
}