How can I display a TextView in the ListView formatted like this "12:30 PM"?

Question

I want to convert that string to DateFormat. In my ListView appears a little bit strange.

Here is the code

        String nameb= jo.getString("name");
        String dateb= jo.getString("date");
        String hourb= jo.getString("hour");


        HashMap<String, String> item = new HashMap<>();
        item.put("name", nameb);
        item.put("date", dateb);
        item.put("hour",hourb);

        list.add(item);
    }
} catch (JSONException e) {
    e.printStackTrace();
}


adapter = new SimpleAdapter(this,list,R.layout.activity_randevular,
new String[]{"name","date","hour"},new int[]{R.id.name,R.id.date,R.id.hour});


listView.setAdapter(adapter);
loading.dismiss();

first I have some strings on GoogleSheet and one of them indicates a hour like "14:00". On GoogleSheet it look perfect but in the ListView looks like this "2001-07-04T12:08:56.235-07:00" and so on. I want it to consist of Hour and Minute.

Answer 1

tl;dr

Use modern java.time classes OffsetDateTime, LocalTime, and DateTimeFormatter, and localize using Locale.

OffsetDateTime                                // Represent a moment as a date and time-of-day with an offset of hours-minutes-seconds ahead of or behind UTC.
.parse( "2001-07-04T12:08:56.235-07:00" )     // Standard ISO 8601 strings can be parsed directly, without you needing to specify a formatting pattern. Returns an `OffsetDateTime` object.
.toLocalTime()                                // Extract just the time-of-day portion, omitting the date and the offset-from-UTC. Returns a `LocalTime` object.
.format(                                      // Generate text to represent the time-of-day value held in this `LocalTime` object.
    DateTimeFormatter                         // Class to control generate text from a date-time object.
    .ofLocalizedTime(                         // Ask `DateTimeFormatter` to automatically localize the presentation formatting of the text.
        FormatStyle.SHORT                     // Specify how long or abbreviated the text should be.
    )                                         // Returns a `DateTimeFormatter` object.
    .withLocale(                              // Specify the locale to use in localization, to determine (a) the human language to use in translation, and (b) the cultural norms to decide issues such as capitalization, abbreviation, punctuation, order of elements. 
        Locale.US
    )                                         // Returns another `DateTimeFormatter` object. The java.time class use the immutable objects pattern, returning a fresh object base on the original’s values rather than changing (“mutating”) the original.
)                                             // Returns a `String`.

12:08 PM

Details

like this "2001-07-04T12:08:56.235-07:00"

That text is in standard ISO 8601 format for a moment.

The modern java.time classes use those standard formats by default when parsing/generating text.

OffsetDateTime odt = OffsetDateTime.parse( "2001-07-04T12:08:56.235-07:00" ) ;

I want it to consist of Hour and Minute.

Do you want to show the time as seen through the same offset-from-UTC? That offset of -07:00, seven hours behind UTC, is possibly from a time zone on the west coast of North America, such as America/Vancouver or America/Los_Angeles as you can see here.

If so, extract the time-of-day.

LocalTime lt = odt.toLocalTime() ;

Then generate a string representing the value of that LocalTime object. Generally best to let java.time automatically localize for you.

Locale locale = Locale.US ;
DateTimeFormatter f = DateTimeFormatter.ofLocalizedTime( FormatStyle.SHORT ).withLocale( locale ) ;

String output = lt.format( f );

12:08 PM

---

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.

Where to obtain the java.time classes?

• Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
  • Java 9 adds some minor features and fixes.
• Java SE 6 and Java SE 7
  • Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
• Android
  • Later versions of Android bundle implementations of the java.time classes.
  • For earlier Android (<26), the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….

Answer 2

You have to convert the timestamp to date to be able to get the time. The input format is the format your timestamp is on your data source. The output format is how it will be shown to the user.

SimpleDateFormat inputFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
SimpleDateFormat outputFormat = new SimpleDateFormat("h:mm a");

try {
    String nameb= jo.getString("name");
    String dateb= jo.getString("date");
    String hourb= jo.getString("hour");

    Date date = inputFormat.parse(hourb);

    HashMap<String, String> item = new HashMap<>();
    item.put("name", nameb);
    item.put("date", dateb);
    item.put("hour", outputFormat.format(date));

    list.add(item);
} catch (ParseException e) {
    e.printStackTrace();
} catch (JSONException e) {
    e.printStackTrace();
}