ResultSet as Iterable…

It’s funny that I keep finding some simple utilities in core Java libraries that are not part of standard JDK after almost 15 years working with Java…

We are adding A LOT of functional APIs to GridGain 3.0 and many of the functional processing of collections works with Iterable interface. Yet – there’s no standard way to convert JDBC ResultSet to Iterable which is really just a few lines of code. Go figure why this was omitted…

The code below provides such conversation. Keep in mind that it is not 100% compatible with Iterator contract as you can’t call hasNext() more than once as it has side effect of advancing the result set. Other than that – you can use it with any functional constructs in GridGain 3.0 that require Iterable.

public static Iterable<ResultSet> asIterable(final ResultSet rs) {
    return new Iterable<ResultSet>() {
        @Override public Iterator<ResultSet> iterator() {
            return new Iterator<ResultSet>() {
               public boolean hasNext() {
                    try {
                    catch (SQLException e) {
                        throw new RuntimeException(e);

                public ResultSet next() {  return rs; }

                public void remove() { 
                    throw new UnsupportedOperationException(); 


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: