用今天、昨天、明天等字符串格式化日期的正确方法

Question

我有一个日期文本视图。我的 textview 包含一个日期字符串，例如 2011.09.17。好吧，我仍然想拥有它，但我也想为今天或昨天等特定日期添加更多用户友好的信息。例如，如果今天是 2011.09.17，我希望我的 textview 具有昨天而不是 2011.09.16 和今天的值 2011.09.17。

好吧，我已经设法做到了 :)，但是以丑陋的方式 :(。我用很多 'if->than' 来做到这一点，这真的很丑陋，而且我想添加一些新规则，比如 if日期超过一年我想把字符串放在去年左右......我真的需要添加丑陋的逻辑。

我的问题是有没有更好的方法来做到这一点？有没有类似设计模式的东西？推荐的方法是什么？相信很多人都遇到过这样的问题

如果有比一千个 if 更有效的方法吗？如果不感谢任何方式，至少我会停止寻找沐浴者解决方案

任何建议，sn-p 左右将不胜感激

谢谢

Answer 1

您可以在 DateUtils 中尝试getRelativeDateTimeString http://developer.android.com/reference/android/text/format/DateUtils.html

Answer 2

我通常使用这个方便的 java 库来格式化相对时间。 Prety Time Library

Answer 3

public class RelativeWeekday {                
    private final Calendar mCalendar;                

    public RelativeWeekday(Calendar calendar) {                
        mCalendar = calendar;                
    }                

    @Override                
    public String toString() {                
        Calendar today = Calendar.getInstance(Locale.getDefault());
        int dayOfYear = mCalendar.get(Calendar.DAY_OF_YEAR);
        if (Math.abs(dayOfYear - today.get(Calendar.DAY_OF_YEAR)) < 2) {
            return getRelativeDay(today);
        }              

        return getWeekDay();                
    }                

    private String getRelativeDay(Calendar today) {                
        return DateUtils.getRelativeTimeSpanString(                
                mCalendar.getTimeInMillis(),                
                today.getTimeInMillis(),                
                DateUtils.DAY_IN_MILLIS,                
                DateUtils.FORMAT_SHOW_WEEKDAY).toString();                
    }                

    private String getWeekDay() {                
        SimpleDateFormat dayFormat = new SimpleDateFormat("EEEE");                
        return dayFormat.format(mCalendar.getTimeInMillis());                
    }                
}

Answer 4

试试这个，我使用 joda-datatime2.2.jar 和 java SimpleDateFormat 实现了它

import java.text.SimpleDateFormat;
import java.util.Date;
import org.joda.time.DateMidnight;
import org.joda.time.DateTime;
import org.joda.time.Days;
public class SmartDateTimeUtil {
private static String getHourMinuteString(Date date){
    SimpleDateFormat hourMinuteFormat = new SimpleDateFormat(" h:m a");
    return hourMinuteFormat.format(date);
}

private static String getDateString(Date date){
    SimpleDateFormat dateStringFormat = new SimpleDateFormat("EEE',' MMM d y',' h:m a");
    return dateStringFormat.format(date);
}

private static boolean isToday (DateTime dateTime) {
       DateMidnight today = new DateMidnight();
       return today.equals(dateTime.toDateMidnight());
}

private static boolean isYesterday (DateTime dateTime) {
       DateMidnight yesterday = (new DateMidnight()).minusDays(1);
       return yesterday.equals(dateTime.toDateMidnight());
}

private static boolean isTomorrow(DateTime dateTime){
    DateMidnight tomorrow = (new DateMidnight()).plusDays(1);
       return tomorrow.equals(dateTime.toDateMidnight());
}
private static String getDayString(Date date) {
        SimpleDateFormat weekdayFormat = new SimpleDateFormat("EEE',' h:m a");
        String s;
        if (isToday(new DateTime(date)))
            s = "Today";
        else if (isYesterday(new DateTime(date)))
            s = "Yesterday," + getHourMinuteString(date);
        else if(isTomorrow(new DateTime(date)))
            s = "Tomorrow," +getHourMinuteString(date);
        else
            s = weekdayFormat.format(date);
        return s;
}

public static String getDateString_shortAndSmart(Date date) {
        String s;
        DateTime nowDT = new DateTime();
        DateTime dateDT = new DateTime(date);
        int days = Days.daysBetween(dateDT, nowDT).getDays();   
        if (isToday(new DateTime(date)))
            s = "Today,"+getHourMinuteString(date);
        else if (days < 7)
            s = getDayString(date);
        else
            s = getDateString(date);
        return s;
}

}

使用和测试Util类的简单案例：

import java.util.Calendar;
import java.util.Date;

public class SmartDateTimeUtilTest {
    public static void main(String[] args) {
        System.out.println("Date now:"+SmartDateTimeUtil.getDateString_shortAndSmart(new Date()));
        System.out.println("Date 5 days before :"+SmartDateTimeUtil.getDateString_shortAndSmart(getFutureDay(-5)));
        System.out.println("Date 1 day before :"+SmartDateTimeUtil.getDateString_shortAndSmart(getFutureDay(-1)));
        System.out.println("Date last month:"+SmartDateTimeUtil.getDateString_shortAndSmart(getFutureMonth(-1)));
        System.out.println("Date last year:"+SmartDateTimeUtil.getDateString_shortAndSmart(getFutureDate(-1)));
        System.out.println("Date 1 day after :"+SmartDateTimeUtil.getDateString_shortAndSmart(getFutureDay(1)));
    }
    public static Date getFutureDate(int numberOfYears){
        Calendar c = Calendar.getInstance();
        c.setTime(new Date());
        c.add(Calendar.YEAR, numberOfYears); 
        return c.getTime();
    }
    public static Date getFutureMonth(int numberOfYears){
        Calendar c = Calendar.getInstance();
        c.setTime(new Date());
        c.add(Calendar.MONTH, numberOfYears); 
        return c.getTime();
    }

    public static Date getFutureDay(int numberOfYears){
        Calendar c = Calendar.getInstance();
        c.setTime(new Date());
        c.add(Calendar.DATE, numberOfYears); 
        return c.getTime();
    }
}

Answer 5

getRelativeTimeSpanString 在 API 级别 3 中添加

getRelativeTimeSpanString（长时间， 很久了， long minResolution)

返回一个字符串，将“时间”描述为相对于“现在”的时间。

过去的时间跨度格式类似于“42 分钟前”。未来时间跨度的格式类似于“42 分钟内”。 您可以在此处找到更多信息：

https://developer.android.com/reference/android/text/format/DateUtils

    Calendar now = Calendar.getInstance();
    return DateUtils.getRelativeTimeSpanString(time, now.getTimeInMillis(), DateUtils.DAY_IN_MILLIS);

Answer 6

对于 android 在 build.gradle 文件中使用 JodaTime 库：

编译'net.danlew:android.joda:2.9.9'

public static String formateddate(String date) {
    DateTime dateTime = DateTimeFormat.forPattern("dd-MMM-yyyy").parseDateTime(date);
    DateTime today = new DateTime();
    DateTime yesterday = today.minusDays(1);
    DateTime twodaysago = today.minusDays(2);
    DateTime tomorrow= today.minusDays(-1);

    if (dateTime.toLocalDate().equals(today.toLocalDate())) {
        return "Today ";
    } else if (dateTime.toLocalDate().equals(yesterday.toLocalDate())) {
        return "Yesterday ";
    } else if (dateTime.toLocalDate().equals(twodaysago.toLocalDate())) {
        return "2 days ago ";
    } else if (dateTime.toLocalDate().equals(tomorrow.toLocalDate())) {
        return "Tomorrow ";
    } else {
        return date;
    }
}