Packaging & Running
Package a Spring Boot app into a JAR and run it in different ways.
Packaging & Running is a free Java Academy lesson on CoddyKit — lesson 3 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
Packaging means building a distributable JAR file that contains your Spring Boot app.
Maven build
Run mvn clean package. It produces a fat JAR under target/.
Code: packaging demo
This demo prints the idea of packaging into a JAR.
public class Main {
public static void main(String[] args) {
System.out.println("Packaging Spring Boot app...");
System.out.println("Created target/app.jar with all dependencies.");
}
}
Run app
Run with java -jar target/app.jar. Spring Boot launches the embedded Tomcat.
Code: run output
This simulates console output of java -jar.
public class Main {
public static void main(String[] args) {
System.out.println("Launching app on port 8080...");
System.out.println("App started successfully. Press Ctrl+C to exit.");
}
}
Docker note
You can also package into a Docker image, then run docker run -p 8080:8080 app.
Packaging check
Quick check: Which command runs a packaged Spring Boot JAR?
Recap
Recap: Built with Maven, ran with java -jar, saw console output, and noted Docker option.
Frequently asked questions
Is the “Packaging & Running” lesson free?
Yes — the full text of “Packaging & Running” 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 “Packaging & Running”?
Package a Spring Boot app into a JAR and run it in different ways. 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 3 of 3, so you can start here or from the beginning and move at your own pace.
How long does the “Packaging & Running” 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
- Testing Spring (WebTestClient/JUnit)
- Config & Profiles
- Packaging & Running