Displaying AM and PM in lower case after date formatting

问题

After formatting a datetime, the time displays AM or PM in upper case, but I want it in lower case like am or pm.

This is my code:

public class Timeis {
    public static void main(String s[]) {
        long ts = 1022895271767L;
        String st = null;  
        st = new SimpleDateFormat(" MMM d 'at' hh:mm a").format(ts);
        System.out.println("time is " + ts);  
    }
}

回答1:

Unfortunately the standard formatting methods don't let you do that. Nor does Joda. I think you're going to have to process your formatted date by a simple post-format replace.

String str = oldstr.replace("AM", "am").replace("PM","pm");

You could use the replaceAll() method that uses regepxs, but I think the above is perhaps sufficient. I'm not doing a blanket toLowerCase() since that could screw up formatting if you change the format string in the future to contain (say) month names or similar.

EDIT: James Jithin's solution looks a lot better, and the proper way to do this (as noted in the comments)

回答2:

This works

public class Timeis {
    public static void main(String s[]) {
        long ts = 1022895271767L;
        SimpleDateFormat sdf = new SimpleDateFormat(" MMM d 'at' hh:mm a");
        // CREATE DateFormatSymbols WITH ALL SYMBOLS FROM (DEFAULT) Locale
        DateFormatSymbols symbols = new DateFormatSymbols(Locale.getDefault());
        // OVERRIDE SOME symbols WHILE RETAINING OTHERS
        symbols.setAmPmStrings(new String[] { "am", "pm" });
        sdf.setDateFormatSymbols(symbols);
        String st = sdf.format(ts);
        System.out.println("time is " + st);
    }
}

回答3:

Try this:

System.out.println("time is " + ts.toLowerCase());

Although you may be able to create a custom format as detailed here and here

Unfortunately out of the box the AM and PM do not seem to be customisable in the standard SimpleDateFormat class

回答4:

Calendar c = Calendar.getInstance();

System.out.println("Current time => " + c.getTime());

SimpleDateFormat df = new SimpleDateFormat("HH:mm a");
String formattedDate = df.format(c.getTime());
formattedDate = formattedDate.replace("a.m.", "AM").replace("p.m.","PM");

TextView textView = findViewById(R.id.textView);
textView.setText(formattedDate);

回答5:

If you don't want to do string substitution, and are using Java 8 javax.time:

Map<Long, String> ampm = new HashMap<>();
ampm.put(0l, "am");
ampm.put(1l, "pm");

DateTimeFormatter dtf = new DateTimeFormatterBuilder()
        .appendPattern("E M/d h:mm")
        .appendText(ChronoField.AMPM_OF_DAY, ampm)
        .toFormatter()
        .withZone(ZoneId.of("America/Los_Angeles"));

It's necessary to manually build a DateTimeFormatter (specifying individual pieces), as there is no pattern symbol for lowercase am/pm. You can use appendPattern before and after.

I believe there is no way to substitute the default am/pm symbols, making this is the only way short of doing the string replace on the final string.

回答6:

James's answer is great if you want different style other than default am, pm. But I'm afraid you need mapping between Locale and Locale specific AM/PM set to adopting the override. Now you simply use java built-in java.util.Formatter class. So an easy example looks like this:

System.out.println(String.format(Locale.UK, "%1$tl%1$tp", LocalTime.now()));

It gives:

9pm

To note that if you want upper case, just replace "%1$tp" with "%1$Tp". You can find more details at http://docs.oracle.com/javase/8/docs/api/java/util/Formatter.html#dt.

回答7:

just add toLowarCase() like this

public class Timeis {
public static void main(String s[]) {
      long ts = 1022895271767L;
      String st = null;  
      st = new SimpleDateFormat(" MMM d 'at' hh:mm a").format(ts).toLowerCase();
      System.out.println("time is " + ts);  
}
}

and toUpperCase() if you want upper case

回答8:

    String today = now.format(new DateTimeFormatterBuilder()
            .appendPattern("MM/dd/yyyy ")
            .appendText(ChronoField.AMPM_OF_DAY)
            .appendLiteral(" (PST)")
            .toFormatter(Locale.UK));

// output => 06/18/2019 am (PST)

Locale.UK => am or pm; Locale.US => AM or PM; try different locale for your needs (defaul, etc.)

来源：https://stackoverflow.com/questions/13581608/displaying-am-and-pm-in-lower-case-after-date-formatting

标签

java

datetime

simpledateformat