java - 如何构建具有自定义一周第一天的区域设置？

Question

我需要一个 Locale 对象，它与另一个对象完全相同，但一周的第一天不同(即:星期日而不是星期六)。

具体来说，我需要一个从星期日开始的阿拉伯-埃及语言环境。我使用的日历控件仅支持更改其语言环境，因此符合我的要求。

Answer 1

Locale对象不控制一周的第一天。这是由 Calendar 完成的按照以下方式上课:

Locale locale = Locale.forLanguageTag("ar-EG");
Calendar calendar = Calendar.getInstance(locale);
calendar.setFirstDayOfWeek(Calendar.SUNDAY);

根据 your comment关于 Gautam Jose 的回答:

Normally this would've been just fine. Thing is, the control I'm using keeps instantiating Calendar objects according to the default locale (application scope wise), so a custom locale. I actually tried reverse engineering the control and it does not provide leeway around the issue due to it using private members (i.e.: inheriting it can't help here)

如果您直接使用 Java 反射 API 更改这些 private 成员，则不需要继承。

首先，检查控件的类以找到 Calendar 字段:

public class CalendarControl {
    private Calendar calendar;
}

现在使用:

CalendarControl control; // The instance to manipulate
try {
    Field field = control.getClass().getDeclaredField("calendar");
    field.setAccessible(true);
    field.set(control, calendar); // Pass the new object we created at top of this answer
} catch (Exception ex) {
    // You must catch NoSuchFieldException and IllegalAccessException here
}