String Array to String separator java

How to convert String Array to String with separator java code, Examples

public static String arrayToString(String[] a, String separator) {
    String result = "";
    if (a.length > 0) {
        result = a[0];    // start with the first element
        for (int i=1; i
            result = result + separator + a[i];
        }
    }
    return result;
}