Parse a URI String into Name-Value Collection

Question

I\'ve got the URI like this:

https://google.com.ua/oauth/authorize?client_id=SS&response_type=code&scope=N_FULL&access_type=offline&redirect_         


        

Answer 1

If you're using Java 8 and you're willing to write a few reusable methods, you can do it in one line.

private Map> parse(final String query) {
    return Arrays.asList(query.split("&")).stream().map(p -> p.split("=")).collect(Collectors.toMap(s -> decode(index(s, 0)), s -> Arrays.asList(decode(index(s, 1))), this::mergeLists));
}

private  List mergeLists(final List l1, final List l2) {
    List list = new ArrayList<>();
    list.addAll(l1);
    list.addAll(l2);
    return list;
}

private static  T index(final T[] array, final int index) {
    return index >= array.length ? null : array[index];
}

private static String decode(final String encoded) {
    try {
        return encoded == null ? null : URLDecoder.decode(encoded, "UTF-8");
    } catch(final UnsupportedEncodingException e) {
        throw new RuntimeException("Impossible: UTF-8 is a required encoding", e);
    }
}

But that's a pretty brutal line.