public void setListeners(final List listeners) {
        // early type check, and avoid aliassing
        this.preListeners = new ArrayList<IReloadablePropertiesListener>();
        for (Object o : listeners) {
            preListeners.add((IReloadablePropertiesListener) o);
        }
    }
public void setListeners ( final List listeners ) { this . preListeners = new ArrayList < IReloadablePropertiesListener > ( ) ; for ( Object o : listeners ) { preListeners . add ( ( IReloadablePropertiesListener ) o ) ; } }
listener , 用于通知回调

@param listeners