Convert string date like 20200917 iso date into readable date format android

I am receiving a date in this format from API: 20200917. How can I convert this into a date?

I assume you are receiving a String representation of a date (not a java.util.Date) which you want to convert to a different format.

One way would be a String manipulation, which shouldn't be the first choice.

Another way would be to use the outdated classes java.util.Date and java.text.SimpleDateFormat to reformat that date String (this is already shown in another answer). But this would neither be my choice due to the use of an old and troublesome API.

Here's how you can do it with java.time (since Java 8):

Java:

public static void main(String[] args) {
	// example input
	String input = "20200917";
	// parse the input String with a formatter that can handle the given format
	LocalDate localDate = LocalDate.parse(input, DateTimeFormatter.BASIC_ISO_DATE;
	/*
	 * now that you have a LocalDate, you can use a custom or built-in formatter to
	 * create a differently formatted String (built-in one used here)
	 */
	String output = localDate.format(DateTimeFormatter.ISO_LOCAL_DATE);
	// and then you can output the result
	System.out.println(String.format("%s ==> %s", input, output));
}

Kotlin:

fun main() {
    val input = "20200917"
    val localDate = LocalDate.parse(input, DateTimeFormatter.BASIC_ISO_DATE
    val output = localDate.format(DateTimeFormatter.ISO_LOCAL_DATE)
    println("$input ==> $output")
}

The output of each of these snippets

20200917 ==> 2020-09-17

EDIT

Hi you can do like this:

String trDate="20200917";    
Date tradeDate = new SimpleDateFormat("yyyyMMdd", 
Locale.ENGLISH).parse(trDate);
String krwtrDate = new SimpleDateFormat("yyyy-MM-dd", 
Locale.ENGLISH).format(tradeDate);