Java fast split(String, String) into arrays

// 22 chars, tar = "__", tarLen = 2
// "hello__there__lol__no_"    -> "hello", "there", "lol", "no_"
//                       | index 21
// "hello____there__lol__no__" -> "hello", "", "there", "lol", "no", ""
private static Boolean matchAt(String src, int srcLen, String tar, int tarLen, int i) {
    if ((i + tarLen) > srcLen) {
        return null;
    }
    for (int j = 1; j < tarLen; j++) {
        if (tar.charAt(j) != src.charAt(i + j)) {
            return Boolean.FALSE;
        }
    }
    return Boolean.TRUE;
}

/**
 * Splits the given string into an array, split by the given splitter string
 * @param string The search source string
 * @param split  The splitter value
 * @return An array of strings
 * @author REghZy
 */
@Nonnull
public static String[] split_old(@Nullable String string, @Nullable String split) {
    int srcLen, tarLen, splitCount;
    if (string == null || (srcLen = string.length()) == 0)
        return EMPTY_STR_ARR;
    if (split == null || (tarLen = split.length()) == 0)
        return charToStringArray(string.toCharArray());

    if ((splitCount = countOccurrences(string, split)) == 0)
        return new String[]{string};

    String[] array = new String[splitCount + 1];
    char first = split.charAt(0);
    int k = 0, last = 0;
    for(int i = 0; i < string.length(); i++) {
        if (string.charAt(i) != first)
            continue;
        Boolean match = matchAt(string, srcLen, split, tarLen, i);
        if (match == null) {
            break;
        }
        else if (match) {
            array[k++] = string.substring(last, i);
            last = i + tarLen;
            i += (tarLen - 1);
        }
    }
    if (last <= srcLen)
        array[k] = string.substring(last);
    return array;
}

/**
 * Searches the given string for all occurrences of the given value
 * @param string The search source string
 * @param value The search value
 * @return The occurrence count of 'value' in 'string'
 * @author REghZy
 */
public static int countOccurrences(String string, String value) {
    int count = 0, len = value.length(), index = -len;
    while ((index = string.indexOf(value, index + len)) != -1)
        ++count;
    return count;
}

/**
 * Splits the given string into an array, split by the given splitter string
 * @param string The search source string
 * @param split  The splitter value
 * @return An array of strings
 * @author REghZy
 */
@Nonnull
public static String[] split(@Nullable String string, @Nullable String split) {
    int srcLen, tarLen, splitCount;
    if (string == null || (srcLen = string.length()) == 0)
        return EMPTY_STR_ARR;
    if (split == null || (tarLen = split.length()) == 0)
        return charToStringArray(string.toCharArray());

    if ((splitCount = countOccurrences(string, split)) == 0)
        return new String[]{string};

    String[] array = new String[splitCount + 1];
    char first = split.charAt(0);
    int i = -tarLen, last = 0, k = 0;
    while ((i = string.indexOf(split, i + tarLen)) != -1) {
        array[k++] = string.substring(last, i);
        last = i + tarLen;
    }
    if (last <= srcLen)
        array[k] = string.substring(last);
    return array;
}