Differences between jar and war in Spring Boot?
JavaSpringSpring BootJarWarJava Problem Overview
I'm about to build my first website in Java with Spring Framework using Spring Boot and it's much easier to build it in jar
, but I have a few questions about it.
What are the differences in general?
In jar
files the views are under /resources/templates
, but in war
file it's under /webapp/WEB-INF/
.
What are the differences? Can I deploy a jar
on an online host?
Java Solutions
Solution 1 - Java
Spring Boot can be told to produce a 'fat JAR' which includes all of your module/service's dependencies and can be run with java -jar <your jar>
. See "Create an executable JAR with Maven" here.
Spring Boot can also be told to produce a WAR file, in which case you'll likely choose to deploy it to a web container such as Tomcat or Jetty.
Plenty more details on Spring Boot deployment here.
Solution 2 - Java
Depends on your deployment. If you are planning to deploy your application to an existing Java EE Application Server (e.g. Tomcat), then standard approach is to perform a war
build.
When you use fat jar approach, your application will be deployed on embedded application container provided by spring boot. Conduct Deploying Spring Boot Applications for more information.
Solution 3 - Java
spring-boot
application as fat *.jar
Running It is possible to build so called fat JAR
that is executable *.jar
file with embedded application container (Tomcat
as default option).
There are spring-boot
plugins for various build systems. Here is the one for maven
: spring-boot-maven-plugin
To execute the kind of fat
*.jar
you could simple run command:
java -jar *.jar
Or using spring-boot-maven
goal:
mvn spring-boot:run
spring-boot
application as *.war
archive
Building The other option is to ship your application as old-fashioned war
file. It could be deployed to any servlet container out there. Here is step by step how-to list:
- Change
packaging
towar
(talking about maven'spom.xml
) - Inherit main
spring-boot
application class fromSpringBootServletInitializer
and overrideSpringApplicationBuilder configure(SpringApplicationBuilder)
method (see javadoc) - Make sure to set the
scope
ofspring-boot-starter-tomcat
asprovided
Solution 4 - Java
I was under the same problem, when I deployed my jar issue free on my local. Then I had to demo it on the server. You can create a war file by changing the pom.xml , tag
<packaging>jar</packaging>
to
<packaging>war</packaging>
and you will have a war file in your target which you can deploy to your server(tomcat in my case)
Solution 5 - Java
If you need to deploy it in an external container, you'll normally have to create a war file (which doesn't have to be executable).
If you want to use the embedded container, you can choose to create an executable .jar file or an executable .war file. AFAIK the only difference is in the layout of the archive, and therefore normally also the layout of your source repository.
E.g. using standard folder structure with Maven / Gradle, static resources for a .jar will need to be in src/main/resources/static
while for a .war file they should be in src/main/webapp
.
Solution 6 - Java
war
file is a Web Application Archive which runs inside an application server while a .jar
is Java Application Archive that runs a desktop application on a user's machine. A war file is a special jar file that is used to package a web application to make it easy to deploy it on an application server.
Solution 7 - Java
Simple and easy answer.
Packaging type jar
represented as standalone application and packaging type war
represented as web application.