如何从Java中的日历对象中构建日，月，年的列表？ [英] How can I build a list of days, months, years from a calendar object in Java?

问题描述

我想为表单创建日期窗口小部件，其中包含几个月，几天，几年的选择列表。由于列表根据月份和年份不同，我无法将其编码到31天。 （例如，二月有28天不是30或31，甚至几年甚至29天）
如何使用日历或 joda 对象来建立这些列表。

I want to build a date widget for a form, which has a select list of months, days, years. since the list is different based on the month and year, i cant hard code it to 31 days. (e.g february has 28 days not 30 or 31 and some years even 29 days) How can I use the calendar or joda object to build me these lists.

推荐答案

我强烈地建议您避免使用Java中的内置日期和时间API。

I strongly recommend that you avoid the built-in date and time APIs in Java.

而是使用 Joda Time 。这个图书馆类似于（希望的）将它变成Java 7，并且比内置的API更加愉快。

Instead, use Joda Time. This library is similar to the one which will (hopefully!) make it into Java 7, and is much more pleasant to use than the built-in API.

现在，是您想知道特定月份的天数的基本问题吗？

Now, is the basic problem that you want to know the number of days in a particular month?

编辑：这是代码（带示例）：

Here's the code (with a sample):

import org.joda.time.*;
import org.joda.time.chrono.*;

public class Test   
{
    public static void main(String[] args)
    {        
        System.out.println(getDaysInMonth(2009, 2));
    }

    public static int getDaysInMonth(int year, int month)
    {
        // If you want to use a different calendar system (e.g. Coptic)
        // this is the code to change.
        Chronology chrono = ISOChronology.getInstance();
        DateTimeField dayField = chrono.dayOfMonth();        
        LocalDate monthDate = new LocalDate(year, month, 1);
        return dayField.getMaximumValue(monthDate);
    }
}

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