unpacking build.gradle and gradlew: a guide to building projects ⚒️🚧

have you ever opened up a new project and wondered what is the mysterious build.gradle file and gradle folder? what do they actually do, and why are they important in projects?

heres’s a quick guide!

---

“back in my day”

before gradle, setting up a Java project meant handling each step manually

• compiling - you had to compile each file with javac

javac MyClass.java

• downloading libraries - you had to download the .jar file

javac -cp library.jar MyClass.java

• running tests - required manual setup and commands

java ~/junit.jar org.junit.runner.JUnitCore com.MyClass

• packaging into JAR file - manually with the jar command

jar cvf Class.jar -C build/classes

time consuming right…?

---

what is build.gradle?

• this file contains instructions and tells Gradle exactly how to build your project

# a basic build.gradle file
plugins {
    id 'java'
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web:2.5.4'
}

tasks.named('test') {
    useJUnitPlatform()
}

• dependencies - external libraries your code needs to function

  • we are adding a library that helps build web applications (spring boot)

• plugins - tools to add features like java support/testing capabilities

  • using the java plugin to work with java code

• build tasks - steps to compile, test, package the code

  • configures our test tasks to use junit testing framework

---

what is gradlew?

• if build.gradle is the instructions for what to do, gradlew is the universal remote control

• ensures that everyone builds the project the same way

• how is it helpful?

  • wrapper script to ensure everyone is using the same version of Gradle

  • gradlew downloads and runs the correct version for the project

  • can automate tasks like compiling, testing, packaging in one line

---

how build.gradle and gradlew work together 🤝

1. run gradlew: run a command like ./gradlew build, which triggers the Gradle build process

2. gradlew looks at build.gradle: Gradle checks build.gradle to follow the instructions

3. building begins! Gradle compiles your code, runs tests and packages everything

---

takeaways 🥡

• build.gradle: project’s recipe - listing dependencies, plugins, tasks needed to build the code

• gradlew: universal remote control - builds project the same way for everyone

they’re like the backstage crew that makes sure everything’s ready, so that You can focus on the main act - coding