public class Test2 {
    // input values:
    final static int[] data = {1, 2, 3, 4, 4, -1, 5, 5, 6, 7, 1};
    // array to hold unique values:
    static int[] unique = new int[data.length];
    // array elements in 'unique' from 0 to 'extent' are meaningful (rest are 0)
    static int extent = 0;

    public static void main(String args[]) {
        // put input values into result array
        for (int val : data) {
            add(val);
        }
        // show result
        for (int index = 0; index < extent; index++) {
            System.out.println(unique[index]);
        }

    }

    // add parameter 'value' into the array 'unique', if it is not
    // already present
    public static void add(int value) {
        // go through 'unique'
        for (int index = 0; index < extent; index++) {
            // if found..
            if (value == unique[index]) {
                return; // leave
            }
        }
        // else add it
        unique[extent] = value;
        extent++;

    }
}