import java.util.Scanner;

 public class Recursion{

        public static void main(String[] args)
        {
                try {   System.out.println(" Please input the base you would like to convert into " );
                        Scanner BaseIn = new Scanner (System.in);
                        int base1 = BaseIn.nextInt();

                        System.out.println( "Now input the number you would like to convert" );
                        Scanner NumIn = new Scanner (System.in);
                        int number = NumIn.nextInt();

                        BaseConversion (number, base1);
                    }

                catch (Exception e)
                {
                System.out.print("somethigng stupid");
                }
        }

        public String BaseConversion(int num, int base)
        {
                if (num < base)
                {
                return new String ("" + num);
                }
                else
                {
                return BaseConversion (num/base, base) + new String("" + (num % base));
                }
        }

}

java Recursion

`new Recursion().baseConversion(number, base1)` //I have changed name according to java conventions.

public class Recursion {

public static void main(String[] args) {
    try {
        System.out
                .println(" Please input the base you would like to convert into ");
        Scanner BaseIn = new Scanner(System.in);
        int base1 = BaseIn.nextInt();

        System.out
                .println("Now input the number you would like to convert");
        Scanner NumIn = new Scanner(System.in);
        int number = NumIn.nextInt();

        System.out.println(new Recursion().baseConversion(number, base1));
    }

    catch (Exception e) {
        System.out.print("somethigng stupid");
    }
}

public String baseConversion(int num, int base) {
    if (num < base) {
        return new String("" + num);
    } else {
        return baseConversion(num / base, base)
                + new String("" + (num % base));
    }
}

}