how to convert milliseconds to date format in android?

Just Try this Sample code:-

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;


public class Test {

/**
 * Main Method
 */
public static void main(String[] args) {
    System.out.println(getDate(82233213123L, "dd/MM/yyyy hh:mm:ss.SSS"));
}


/**
 * Return date in specified format.
 * @param milliSeconds Date in milliseconds
 * @param dateFormat Date format 
 * @return String representing date in specified format
 */
public static String getDate(long milliSeconds, String dateFormat)
{
    // Create a DateFormatter object for displaying date in specified format.
    SimpleDateFormat formatter = new SimpleDateFormat(dateFormat);

    // Create a calendar object that will convert the date and time value in milliseconds to date. 
     Calendar calendar = Calendar.getInstance();
     calendar.setTimeInMillis(milliSeconds);
     return formatter.format(calendar.getTime());
}
}

Convert the millisecond value to Date instance and pass it to the choosen formatter.

SimpleDateFormat formatter = new SimpleDateFormat("dd/MM/yyyy"); 
String dateString = formatter.format(new Date(dateInMillis)));

public static String convertDate(String dateInMilliseconds,String dateFormat) {
    return DateFormat.format(dateFormat, Long.parseLong(dateInMilliseconds)).toString();
}

Call this function

convertDate("82233213123","dd/MM/yyyy hh:mm:ss");

tl;dr

Instant.ofEpochMilli( myMillisSinceEpoch )           // Convert count-of-milliseconds-since-epoch into a date-time in UTC (`Instant`).
    .atZone( ZoneId.of( "Africa/Tunis" ) )           // Adjust into the wall-clock time used by the people of a particular region (a time zone). Produces a `ZonedDateTime` object.
    .toLocalDate()                                   // Extract the date-only value (a `LocalDate` object) from the `ZonedDateTime` object, without time-of-day and without time zone.
    .format(                                         // Generate a string to textually represent the date value.
        DateTimeFormatter.ofPattern( "dd/MM/uuuu" )  // Specify a formatting pattern. Tip: Consider using `DateTimeFormatter.ofLocalized…` instead to soft-code the formatting pattern.
    )                                                // Returns a `String` object.
    

java.time

The modern approach uses the java.time classes that supplant the troublesome old legacy date-time classes used by all the other Answers.

Assuming you have a long number of milliseconds since the epoch reference of first moment of 1970 in UTC, 1970-01-01T00:00:00Z…

Instant instant = Instant.ofEpochMilli( myMillisSinceEpoch ) ;

To get a date requires a time zone. For any given moment, the date varies around the globe by zone.

ZoneId z = ZoneId.of( "Pacific/Auckland" ) ;
ZonedDateTime zdt = instant.atZone( z ) ;  // Same moment, different wall-clock time.

Extract a date-only value.

LocalDate ld = zdt.toLocalDate() ;

Generate a String representing that value using standard ISO 8601 format.

String output = ld.toString() ;

Generate a String in custom format.

DateTimeFormatter f = DateTimeFormatter.ofPattern( "dd/MM/uuuu" ) ;
String output = ld.format( f ) ;

Tip: Consider letting java.time automatically localize for you rather than hard-code a formatting pattern. Use the DateTimeFormatter.ofLocalized… methods.

---

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. Hibernate 5 & JPA 2.2 support java.time.

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 brought 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 (26+) bundle implementations of the java.time classes.
  • For earlier Android (<26), the process of API desugaring brings a subset of the java.time functionality not originally built into Android.
    • If the desugaring does not offer what you need, the ThreeTenABP project adapts ThreeTen-Backport (mentioned above) to Android. See How to use ThreeTenABP….