binary to octal in java

                                    import java.util.Scanner;
public class OctalToBinaryJava
{
   public static void main(String[] args)
   {
      Scanner sc = new Scanner(System.in);
      System.out.println("Please enter octal number: ");
      int octal = Integer.parseInt(sc.nextLine(), 8);
      String strBinary = Integer.toBinaryString(octal);
      System.out.println("Binary value is: " + strBinary);
      sc.close();
   }
}

                                    // conversion of binary to octal in java..
public class Main{
    public static void main(String args[]) throws Exception{
        String binary = "1100100";                // binary number.. 
        int decimal = Integer.parseInt(binary,2); // converting binary to decimal
        System.out.println(Integer.toOctalString(decimal)); // 144 <= octal output..  
    }
}

                                    public class BinaryToOctal
{
   public static void main(String[] args)
   {
      long binaryNumber = 1010111;
      int octalNumber = convertToOctal(binaryNumber);
      System.out.println(binaryNumber + " in binary is equal to " + octalNumber + " in octal.");
   }
   public static int convertToOctal(long binaryNumber)
   {
      int octal = 0, decimal = 0, a = 0;
      while(binaryNumber != 0)
      {
         decimal += (binaryNumber % 10) * Math.pow(2, a);
         ++a;
         binaryNumber /= 10;
      }
      a = 1;
      while(decimal != 0)
      {
         octal += (decimal % 8) * a;
         decimal /= 8;
         a *= 10;
      }
      return octal;
   }
}