# Build a Jar with Gradle

In this article, I'll show you how to build a Jar file using the Gradle build system. Let's get started.

# Do you need a Fat Jar?

Before we dive into the process of building a Jar, let's address whether or not you need a fat jar. But wait,
#### What's a fat jar? 

> The fat jar is the jar, which contains classes from all the libraries, on which your project depends as well as the classes of the current project.

In other words, a fat jar is self-contained and when executed like `java -jar my-fat-jar.jar`, it will work without setting up any other dependencies.

Let's see how to set it up. 

In your `build.gradle.kts` add the following lines:
```kotlin
tasks.withType<Jar>() {

    // ...

    from(sourceSets.main.get().output)

    dependsOn(configurations.runtimeClasspath)
    from({
        configurations.runtimeClasspath.get()
            .filter { it.name.endsWith("jar") }
            .map { zipTree(it) }
    })
}
```

and that's it. This will now build a fat jar, if in case you decide you don't need it, just delete these lines.

# Building the Jar

Building a Jar is a fairly simple process

- Open the Gradle tab, go to `Tasks/build/jar` and create a jar file.
![Task: build jar](https://cdn.hashnode.com/res/hashnode/image/upload/v1633961926675/Ew1rNOL1-.png)
    
- The jar file would most likely be created at `/build/libs/`
![jar location](https://cdn.hashnode.com/res/hashnode/image/upload/v1633962172277/wgElp8ULT.png)

### Credits
Cover Image: Photo by <a href="https://unsplash.com/@cameramandan83?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText">Dan Dennis</a> on <a href="https://unsplash.com/s/photos/jar?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText">Unsplash</a>