Inference Engine implementation in java

I am trying to think of an algorithm where I can create number of possible binary combinations for my inference engine implementation

in short if input file to my program has 4 distinct variables my program should be able to generate

0000 0001 0010 . . . 1111

combinations.... So far my approach to this problem is as below which is just a thought as it is hard coded at the moment... Basically I need algorithm to generate this for any given number of variable "n".

My Code so far...

public class TTAlgorithm {

    public static void main(String[] args) {
        Integer j = new Integer(10);

        for (int i = 0; i < 4096; i++) {
            if (j.toBinaryString(i).length() == 1) {
                System.out.println("0000000000" + j.toBinaryString(i));
            }

            if (j.toBinaryString(i).length() == 2) {
                System.out.println("000000000" + j.toBinaryString(i));
            }

            if (j.toBinaryString(i).length() == 3) {
                System.out.println("00000000" + j.toBinaryString(i));
            }

            if (j.toBinaryString(i).length() == 4) {
                System.out.println("0000000" + j.toBinaryString(i));
            }

            if (j.toBinaryString(i).length() == 5) {
                System.out.println("000000" + j.toBinaryString(i));
            }

            if (j.toBinaryString(i).length() == 6) {
                System.out.println("00000" + j.toBinaryString(i));
            }

            if (j.toBinaryString(i).length() == 7) {
                System.out.println("0000" + j.toBinaryString(i));
            }

            if (j.toBinaryString(i).length() == 8) {
                System.out.println("000" + j.toBinaryString(i));
            }

            if (j.toBinaryString(i).length() == 9) {
                System.out.println("00" + j.toBinaryString(i));
            }

            if (j.toBinaryString(i).length() == 10) {
                System.out.println("0" + j.toBinaryString(i));
            }

            if (j.toBinaryString(i).length() == 11) {
                System.out.println("" + j.toBinaryString(i));
            }
        }

    }
}

Thanks for any help....

Solution

This should work...

public static void main(String[] args) throws Exception {
        int count = 0;

        int stringSize = 4;
        int maxValue= (int)Math.pow(2, stringSize);

        while(count < maxValue) {
            String binaryString = Integer.toBinaryString(count);

            while(binaryString.length() < stringSize) {
                binaryString = "0" + binaryString;
            }

            System.out.println(binaryString);
            count++;
        }

    }

Output is...

Put that in a method and have the method take an argument "stringSize" or whatever you want to call it.