java integer to binary string

1int n = 1000;
2String s = Integer.toBinaryString(n);

1import java.util.*;
2import java.util.Scanner;
3public class IntegerToBinary
4{
5   public static void main(String[] args)
6   {
7      int num;
8      String str = "";
9      Scanner sc = new Scanner(System.in);
10      System.out.println("Please enter the a number : ");
11      num = sc.nextInt();
12      // convert int to binary java
13      while(num > 0)
14      {
15         int y = num % 2;
16         str = y + str;
17         num = num / 2;
18      }
19      System.out.println("The binary conversion is : " + str);
20      sc.close();
21   }
22}

1public static String makeBinaryString(int n) {
2	StringBuilder sb = new StringBuilder();
3	while (n > 0) {
4    sb.append(n % 2);
5		n /= 2;
6	}
7  	sb.reverse();  	
8  	return sb.toString();
9}