Code360 powered by Coding Ninjas X Code360 powered by Coding Ninjas X
Table of contents
File Formats of Packaging
Advantages of using a WAR file
Disadvantages of using a WAR file
Advantages of using a JAR file
Disadvantages of using a JAR file
Advantages of using an EAR file
Disadvantages of using EAR file
Difference between WAR and JAR packaging
Key Takeaways
Last Updated: Mar 27, 2024

Spring Boot Packaging

Author Naman Kukreja
0 upvote
Leveraging ChatGPT - GenAI as a Microsoft Data Expert
Prerita Agarwal
Data Specialist @
23 Jul, 2024 @ 01:30 PM


Nowadays, there are many frameworks available. Still, some of them are not lightweight, so unhandy to use, and for those modules, the packaging is a big issue.

It's where the spring framework comes into view. It is a very light framework, and along with that, it also provides predefined templates JPA, Hibernate, JDBC, etc., and it provides packaging and that we are going to study further in this blog.

File Formats of Packaging

Modules are packed as WAR, JAR, and EAR in the J2EE application. In J2EE, these are the compressed file formats.

Spring boot packaging provides a jar file as its default mode of packaging modules.


It stands for Web Archive. These files represent web applications. The Web modules, HTML files, JSP files, JavaScripts, servlet classes, etc., all are present with the .war extension but packaged as a JAR file. It also contains a unique directory named WEB-INF.

Spring mainly focuses on JAVA as War concentrates primarily on the Web, so the war module loads into the web container of the JAVA application server. And this application server of java has two containers: the EJB container and the Web container.

The EJB container hosts the EJB API-based enterprise java beans. All the EJB modules are required to be packaged as a JAR file. In the META_INF folder, it contains an ejb-jar.xml file.

The Web Container hosts servlet API and JSP-based web applications. The web container requires the web module to be packaged as a WAR file. There is a web.xmlv file in the WEB-INF folder that is a WAR file special JAR file.

Advantages of using a WAR file

  • The MVC structure supports WAR files.
  • The version identification of the deployed application becomes effortless.
  • All J2EE containers support WAR files.
  • Easy deployment and testing of web applications.

Disadvantages of using a WAR file

  • : The source code must be repackaged and deployed in development whenever you change the source code.
        // *.jar files as libs


JAR stands for Java Archive. An Enterprise Java Bean(EJB) Module that contains a manifest, an EJB deployment descriptor(XML file) and class files(bean files) with an extension .jar are packaged as JAR files.

Software developers use this to distribute various metadata and Java classes.

A JAR file is a file that encapsulates a manifest, a descriptor, and one or more Java classes. The lowest level of the archive is JAR. For packaging client-side and EJb java applications in J2EE, JAR is used, and it makes the deployment easy.

Advantages of using a JAR file

  • The enhancement of technology provides a digital signature.
  • It is effortless to maintain, handle, create.
  • It is used for its compression abilities.
  • Packaging reduces the burden of managing multiple modules burden.

Disadvantages of using a JAR file

  • Longer download times.
  • Extra work to retrieve sources.


EAR stands for Enterprise Archive. This file represents the enterprise application. The WAR and JAR files are packaged as a JAR file with .ear extension. The EAR file deploys modules into the Application server.

It plays a crucial role in deploying service to a production server. It can contain multiple Web modules and EJB modules. As in the META-INF folder, it includes an application.xml file, and because of this, it is known as a special JAR.

Advantages of using an EAR file

  • Can aggregate several, unlike applications.
  • The file size can be reduced.
  • Restoring links is not necessary.
  • Comparatively easier to deploy than the above two.

Disadvantages of using EAR file

  • Requires a java platform completely.
<?XML version="1.0"?> <jboss-app> <loader-repository> loader=nameofyourear.ear <loader-repository-config>java2ParentDelegation=false</loader-repository-config> </loader-repository> </jboss-app>
Get the tech career you deserve, faster!
Connect with our expert counsellors to understand how to hack your way to success
User rating 4.7/5
1:1 doubt support
95% placement record
Akash Pal
Senior Software Engineer
326% Hike After Job Bootcamp
Himanshu Gusain
Programmer Analyst
32 LPA After Job Bootcamp
After Job

Difference between WAR and JAR packaging

  1. The most obvious one is the file extension. War file has .war extension, whereas Jar file has .jar extension.
  2.  War files use only web applications, whereas jar files use to package multiple files to use them as plugins or a library.
  3. War has a predefined structure, whereas Jar files can be created in any structure.
  4. We need a server to execute the War file, whereas command lines run the jar files.


  1. What is spring?
    It is a framework that is used for the development of enterprise java. It makes J2EE easy to use.
  2. What are the advantages of using spring?
    Some advantages of using spring are its lightweight nature, MVC framework, exception handling, etc.
  3. Which is the most preferred for spring boot application among the three types discussed above?
    Jar is the most preferred one.
  4. Name some of the modules in the spring Framework.
    Some of the modules are Web module, ORM module, OXM module, Core module, etc.

Key Takeaways

This blog has discussed different packaging file formats, their advantages and disadvantages, and the difference between war and jar type file formats.

Recommended Readings:

If you want to explore more frameworks like spring, you should refer to this coding ninja article. You will know the latest top 10 web development frameworks. You can also consider our Spring Boot Course to give your career an edge over others.

Live masterclass