Spring Boot package web application to .jar

Question

Why Spring Boot by default packaging web applications as .jar ? Are there any advantages over .war ?

Shouldn\'t be all web applications packed as .war i

Answer 1

You linked to a question about a WAR vs a JAR, while Spring boot's JAR is indeed a JAR, it contains more than what you usually put inside a JAR. Spring boot comes with an embedded servlet container, inside the JAR itself.

So the difference:

• A JAR: Usually contains resources/libraries/desktop applications/...
• A WAR: A web application that can be run on a web container
• The Spring boot fat JAR: A web application that runs on its own web container

About your question:

Shouldn't be all web applications packed as .war in order to be deployed to real web server?

If you want to run a web application on an existing servlet container, you have to use a WAR file. But the Spring boot JAR comes with its own servlet container, so you can perfectly run it as well.

Which of the two you choose is your own choice. Even though Josh Long's mantra is "Make JAR, not WAR".