Design
Plan how to design the Parallel Stats project, defining requirements and approach.
Design is a free Java Academy lesson on CoddyKit — lesson 1 of 3. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Java Academy learning path, one of 3 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Intro
This mini project: compute statistics (sum, average, max) on large datasets using parallel streams.
Requirements
- Input: large list of numbers
- Outputs: sum, average, min, max
- Performance: should scale with cores
Why parallel
Parallel streams allow dividing computation across CPU cores, useful for big lists.
Code: simple sum
Even this small demo shows how parallelStream() works. With larger inputs, the benefit is bigger.
import java.util.*;public class Main {
public static void main(String[] args) {
List<Integer> nums = Arrays.asList(1,2,3,4,5);
int sum = nums.parallelStream().mapToInt(n -> n).sum();
System.out.println("Sum = " + sum);
}
}
Handling results
Plan to compute multiple stats: min, max, sum, average. Decide whether to run them in one stream or separate pipelines.
Testing
Test with small and large datasets. Measure speed difference between sequential and parallel streams.
Design check
Quick check: Why use parallel streams for statistics on large data?
Recap
Recap: Defined project requirements, justified parallel streams, and sketched a plan. Next: Implementation.
Frequently asked questions
Is the “Design” lesson free?
Yes — the full text of “Design” is free to read here on the web, and the Java Academy course includes 3 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Java Academy course, upgrade to CoddyKit PRO.
What will I learn in “Design”?
Plan how to design the Parallel Stats project, defining requirements and approach. You practise Java Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Java Academy?
No prior experience is required. Java Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 3, so you can start here or from the beginning and move at your own pace.
How long does the “Design” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Java Academy lesson?
Yes. Every Java Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Design
- Implementation
- Benchmarks