Lambda Expressions Require "Final" or "Effectively Final" Variables

The error message "Variable used in lambda expression should be final or effectively final" indicates that a variable used within a lambda expression must be declared as final or meet specific criteria to be considered effectively final。

錯誤被拋出，因為caltz變量在lambda表達式中未聲明為最終。 Java要求lambda表達式中使用的變量是最終或有效的最終來防止潛在的並發問題。

private TimeZone extractCalendarTimeZoneComponent(Calendar cal, TimeZone calTz) {
    // Code missing
    cal.getComponents().getComponents("VTIMEZONE").forEach(component -> {
        // Code missing
        if (calTz == null) {
            calTz = TimeZone.getTimeZone(v.getTimeZoneId().getValue());
        }
    });
    // Code missing
}