How to sort an array using for loop

import java.util.*;

public class Main {
    public static void main(String[] args) {
      int a[]={7,4,2,4,1};
      for(int i=0;i<a.length;i++){
        for(int j=0;j<a.length;j++){
         if(a[i]<a[j]){
          int temp=a[i];
          a[i]=a[j];
          a[j]=temp;
        } 
        }
      }
      System.out.println(Arrays.toString(a));
  }
}