如何从给定范围加载日期数组？

Question

我正在寻找在我的 recyclerview 中填充日期范围的最佳方式。为了阐明，我想获取从当前日期到接下来的 7 天的所有日期，就像今天是 29-07-2020 我想列出从 29-07-2020 到 04-07-2020 的所有日期。现在在我的回收站中，我想获取日期和月份名称。我尝试了下面的代码，它按照我的意愿列出了日期，但我不确定如何单独获取日期和月份。

List<String> dateList = new ArrayList<String>();
    Calendar calendar = Calendar.getInstance();
    for (int i=0; i<31; i++) {
        calendar.add(Calendar.DATE, 1);
        SimpleDateFormat curFormater = new SimpleDateFormat("EEEE, MMMM dd, yyyy");
        dateList.add(curFormater.format(calendar.getTime()));

        Log.i("Date" + i , dateList.get(i));
    }

Answer 1

您可能应该考虑 https://developer.android.com/reference/java/util/Calendar#get(int) 并获得这样的月份：

calendar.get(Calendar.MONTH)

或像这样的一个月中的某天：

calendar.get(Calendar.DAY_OF_MONTH)

Answer 2

通过更改您传递给 SimpleDateFormat 的字符串来编辑日期格式。要仅显示日期和月份，您可以尝试：

SimpleDateFormat curFormater = new SimpleDateFormat("dd MMMM");

更多关于格式化日期的信息here

Answer 3

我建议您从过时的旧版 date-time API 切换到 modern date-time API。

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        LocalDate today = LocalDate.now();// Same as LocalDate.now(ZoneId.systemDefault());
        // I suggest you use the following variant and apply the required time-zone
        // LocalDate today=LocalDate.now(ZoneId.of("Etc/UTC"));

        List<String> dateList = new ArrayList<String>();

        // Define the format
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("EEEE, MMMM");

        // Iterate 7-times starting today with date incrementing by 1 after each iteration
        for (LocalDate date = today; date.isBefore(today.plusDays(7)); date = date.plusDays(1)) {
            dateList.add(date.format(formatter));
        }

        // Display the content of dateList
        dateList.forEach(System.out::println);
    }
}

输出：

Monday, August
Tuesday, August
Wednesday, August
Thursday, August
Friday, August
Saturday, August
Sunday, August

如果您的 Android 版本与 Java-8 不兼容，您可以使用 ThreeTen-Backport. You may also need .

向后移植

但是，如果您想坚持遗留 date-time API，请按以下步骤操作：

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        Calendar calendar = Calendar.getInstance();
        List<String> dateList = new ArrayList<>();

        // Define the format for only day-name and month-name 
        SimpleDateFormat curFormater = new SimpleDateFormat("EEEE, MMMM");

        // Iterate 7-times starting today with date incrementing by 1 after each iteration
        for (int i = 1; i <= 7; i++) {
            dateList.add(curFormater.format(calendar.getTime()));
            calendar.add(Calendar.DATE, 1);
        }

        // Display the content of dateList
        dateList.forEach(System.out::println);
    }
}

输出：

Monday, August
Tuesday, August
Wednesday, August
Thursday, August
Friday, August
Saturday, August
Sunday, August

如何从给定范围加载日期数组？

How to load array of dates from a given range?

java

android

date

simpledateformat