How to cast type safety a Object to JComboBox<String>?

问题

I have this code:

@Override
public void itemStateChanged(ItemEvent evt) {
    if (evt.getStateChange() == ItemEvent.SELECTED) {
        Object sourceObject = evt.getSource();

        if (sourceObject instanceof JComboBox<?>) {
            JComboBox<String> jComboBox = (JComboBox<String>) sourceObject;
        }
    }
}

What is the best and correct casting for generics type safety and avoiding suppress the warning?

回答1:

You nailed it. Runtime instanceof checks don't check generic parameters so the way you have shown it is the standard way that it is done.

来源：https://stackoverflow.com/questions/59539568/how-to-cast-type-safety-a-object-to-jcomboboxstring