How to sort a number in java android?

You can convert your int into a String and split in a array, next just sort the stream and join in a single String.

String[] number = "190".split("");

String list =  Stream.of(number).sorted().collect(Collectors.joining());

System.out.println(list); //Output: 019

You can do it like this:

   package test;

    public class Test2 {

        public static void main(String[] args) throws Exception {
            String number = "153004";
            String sorted = sortStringNumbers(number);
            System.out.println(sorted);
        }

        private static String sortStringNumbers(String numbersString) {
            return numbersString.chars().mapToObj(c -> Character.toString((char)c)).sorted().collect(Collectors.joining());
        }

    }

Output:

001345

You can create a List with the digits of your number and sort this List.

List<Integer> nums=new ArrayList<>();
for(int num=toSort;num>0;num/=10){
    nums.add(num%10);
}
Collections.sort(nums);
String result="";//If you want the result to be a integer (e.g. 190 will convert into 19 and not 019), change this to int result=0;
for(Integer num:nums){
    result+=num.intValue();
    /*int:
    result+=num.intValue();
    result×=10;*/
}

From my understanding of your question you are trying to sort the digits in an int. This can be done by converting to a CharArray, sorting, then returning the result. Note that this will fail for negative numbers.

fun sortInt(int: Int): Int =
        int.toString()
                .toCharArray()
                .sorted()
                .joinToString("")
                .toInt()

EDIT: Now this will work for 0 digit also.

fun sortInt(int: Int): String =
        int.toString()
                .toCharArray()
                .sorted()
                .joinToString("")

Plenty of ways to achieve this. Here's one:

final String sorted = "190".chars()
    .sorted()
    .mapToObj(c -> Character.valueOf((char)c).toString())
    .collect(Collectors.joining())

and

final String sorted = "190".chars()
    .sorted()
    .collect(StringBuilder::new, (sb, c) -> sb.append((char) c), StringBuilder::append)
    .toString();

And, as a single-liner that will (I think) work in Java 7 (not production code but fun to do)...

final String sorted = Arrays.toString(new PriorityQueue<>(Arrays.asList("190".split("")))
    .toArray(new String[0]))
    .replaceAll("\\W+", "");

Updates @dan1st answer, to get desired result:

        List<Integer> nums = new ArrayList<>();
        String total = "";
        for( int num = 190; num>0; num/=10 ){
            nums.add(num%10);
        }
        Collections.sort(nums);
        for (Integer x : nums) {
            total += x.toString();
        }
        Integer finalResult = Integer.parseInt(total);
        Log.i(TAG,"=== finalResult  "+ finalResult);
        O/P : 019

you should be care if you use this :

sortInt(190)

fun sortInt(int: Int): Int =
        int.toString()
                .toCharArray()
                .sorted()
                .joinToString("")
                .toInt()

the output will be 19 and not 019