Design
Design a log analyzer: requirements, inputs, outputs, and basic architecture.
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
Goal: Design a Log Analyzer that reads log files, searches for errors/warnings, and reports summaries.
Requirements
- Input: log file (plain text)
- Process: scan lines for ERROR/WARN
- Output: counts and simple summaries
Code: check error
A simple check: if a log line contains ERROR, mark it as an error entry.
public class Main {
public static void main(String[] args) {
String logLine = "2025-01-01 ERROR Something failed";
if (logLine.contains("ERROR")) {
System.out.println("Found error line");
}
}
}
Architecture
Architecture: one class to read lines, one class to analyze, one class to report.
Code: pipeline outline
This placeholder code shows the 3-part pipeline.
public class Main {
public static void main(String[] args) {
System.out.println("Reader -> Analyzer -> Reporter");
}
}
Example output
Example output: Errors: 5, Warnings: 3. Keep it simple and readable for beginners.
Design check
Quick check: What is the main purpose of the Log Analyzer?
Recap
Recap: We defined requirements, looked at example logs, planned architecture, and target output.
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”?
Design a log analyzer: requirements, inputs, outputs, and basic architecture. 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
- Reporting