How to Run a Jar File

In Java development, once you compile and package your application, the result is often a single archive file called a JAR file. If you’re a beginner and have no idea how to run this file, don’t worry! This article will guide you step-by-step in understanding what a JAR file is and how to run it on your system.

What is a JAR File?

JAR stands for Java ARchive. It is a file format based on the ZIP file format and is used to package Java classes, metadata, and resources (like images, property files, etc.) into a single file. JAR files are commonly used to distribute Java applications and libraries.

Uses of JAR File

Some of the uses of the jar file are as follows:

• Package all class files and resources into a single executable file.
• Share Java libraries or frameworks for reuse.
• Reduce the complexity of application deployment.
• Run standalone Java applications using the java -jar command.
• Ensure versioning and easier dependency management.

Steps to Run a JAR File

To run a JAR file, you need to have Java installed on your computer. Follow these steps:

Install Java

Download and install the latest Java Runtime Environment (JRE) or Java Development Kit (JDK) from the official website:

• https://www.oracle.com/java/technologies/javase-downloads.html

Open the Command Prompt

Open Command Prompt on Windows or Terminal on macOS/Linux.

Navigate to the Folder Containing the JAR File

Use the cd command to change the directory to where the JAR file is located. Example:

/> cd C:\Users\<YourName>\Downloads

Run the JAR File

Use the following command to run the JAR file:

/> java -jar yourfile.jar

Replace yourfile.jar with the name of your JAR file. If the file is an executable JAR, it will launch the application.

Difference Between JAR and WAR File

Some of the differences between jar and war file are as follows:

Feature	JAR File	WAR File
Full Form	Java ARchive	Web Application ARchive
Purpose	Used to package Java classes and resources	Used to package web applications
Contents	Class files, libraries, resources	HTML, JSP, Servlets, class files, web.xml
Deployment	Run with Java command line	Deployed on a web server like Apache Tomcat
Target Application	Standalone Java applications	Java web applications