Variable used in lambda expression should be final or effectively final

Question

Variable used in lambda expression should be final or effectively final

When I try to use calTz it is showing this error.

Answer 1

From a lambda, you can't get a reference to anything that isn't final. You need to declare a final wrapper from outside the lamda to hold your variable.

I've added the final 'reference' object as this wrapper.

private TimeZone extractCalendarTimeZoneComponent(Calendar cal,TimeZone calTz) {
    final AtomicReference reference = new AtomicReference<>();

    try {
       cal.getComponents().getComponents("VTIMEZONE").forEach(component->{
        VTimeZone v = (VTimeZone) component;
           v.getTimeZoneId();
           if(reference.get()==null) {
               reference.set(TimeZone.getTimeZone(v.getTimeZoneId().getValue()));
           }
           });
    } catch (Exception e) {
        //log.warn("Unable to determine ical timezone", e);
    }
    return reference.get();
}