GradleのインストールとCLI

The Gradle Command Line Interface (CLI) is your main tool for interacting with Gradle. It's how you tell Gradle what to do, like building your project or running tests.

Understanding the CLI is crucial for automating your build processes and managing your projects effectively.

Before installing Gradle, you need to have the Java Development Kit (JDK) installed on your system. Gradle runs on the Java Virtual Machine (JVM), just like Java applications.

• Ensure you have JDK 8 or higher.
• You can check your Java version with: java -version

There are several ways to install Gradle. For beginners, using a version manager like SDKMAN! is highly recommended. It simplifies managing multiple SDK versions.

• SDKMAN!: Easy and flexible.
• Manual Download: More setup required.
• Package Managers: Homebrew (macOS), Chocolatey (Windows).

SDKMAN! (Software Development Kit Manager) makes installing Gradle super easy. If you don't have SDKMAN!, install it first by following instructions on sdkman.io.

Once SDKMAN! is ready, open your terminal and run:

After installation, it's a good practice to verify that Gradle is correctly installed and accessible from your terminal. This command shows the Gradle version and other environment details.

Run this in your terminal:

The most common command to start with is gradle tasks. This command lists all available tasks for the current project. If you're not in a Gradle project, it shows generic tasks.

Let's try it:

When you run gradle tasks, you'll see categories like "Build tasks", "Verification tasks", etc., each with a list of tasks and their descriptions.

• Tasks: Are the actual actions Gradle performs (e.g., build, clean, test).
• Description: Explains what each task does.

This output helps you understand what operations your project supports.

Gradle has a built-in help system. If you want to know more about a specific task, you can use the help task with the --task option.

For example, to learn about the build task:

Many Gradle projects include a Gradle Wrapper (gradlew or gradlew.bat). This script ensures everyone uses the same Gradle version for a project, even if they don't have Gradle installed globally.

You'll often run commands like ./gradlew build instead of gradle build.

Great job! In this lesson, you learned how to:

• Understand the role of the Gradle CLI.
• Install Gradle using SDKMAN!.
• Verify your installation with gradle -v.
• List available tasks using gradle tasks.
• Get help for specific tasks with gradle help --task <taskName>.
• Briefly grasp the concept of the Gradle Wrapper.

Next, we'll dive into setting up a basic Gradle project!