package ch.claude_martin;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.function.Consumer;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

class SomeClass {
	public static void main(String[] args) throws Throwable {
		Connection conn = null;
		PreparedStatement stmt = conn.prepareStatement("SELECT * FROM FOO", ResultSet.TYPE_SCROLL_INSENSITIVE,
				ResultSet.CONCUR_READ_ONLY);
		ResultSet rs = stmt.executeQuery();
		long size;
		try {
			rs.last();
			size = rs.getRow();
			rs.beforeFirst();
		} catch (Exception ex) {
			size = Long.MAX_VALUE;
		}
		Stream<Foo> stream = StreamSupport.stream(new AbstractSpliteratorExtension(rs, size), false);

		var result = stream.map(mapper1).map(mapper2).filter(someFilter).collect(myCollector);
	}

	private static final class AbstractSpliteratorExtension extends Spliterators.AbstractSpliterator<Foo> {
		private final ResultSet rs;

		private AbstractSpliteratorExtension(ResultSet rs, long size) {
			super(size, Spliterator.ORDERED);
			this.rs = rs;
		}

		@Override
		public boolean tryAdvance(Consumer<? super Foo> action) {
			try {
				if (!rs.next())
					return false;
				action.accept(Foo.of(rs));
				return true;
			} catch (SQLException e) {
				throw new RuntimeException(e);
			}
		}
	}

	public static class Foo {
		public static Foo of(ResultSet rs) { ... }
	}
}