CLI Application with Picocli

This project is a simple Command Line Interface (CLI) application built using the Picocli library. The application has two subcommands (hello and goodbye) that demonstrate how to use Picocli to create a CLI with subcommands.

Features

• hello: Prints a greeting message.
• goodbye: Prints a farewell message.
• You can pass options such as --greetings and --farewells to customize the messages.
• Default values are used when no name or message is provided.

Structure

The project consists of the following key files:

• Main.java: The main class that handles command-line parsing and execution.
• Hello.java: A subcommand that prints a greeting message.
• Goodbye.java: A subcommand that prints a farewell message.

Prerequisites

Make sure you have the following installed:

• Java JDK 11+
• Maven (for building the project)

Build Instructions

1. Clone the repository:

   git clone <repository-url>
   cd <project-directory>
   

2. Build the project using Maven:

    mvn clean package
   

   This will generate a JAR file in the target directory.

3. Running the Application

   Once the project is built, you can run the application from the command line. Run the JAR

   java -jar target/<project-name>.jar [subcommand] [options]
   

4. Example Usage

   Print a greeting:

   java -jar target/myapp.jar hello
   

   Output: Hello World!

   Customize the greeting message:

   java -jar target/myapp.jar hello --greetings "Hi"
   

   Output: Hi World!

   Say goodbye:

   java -jar target/myapp.jar goodbye
   

   Output: Goodbye World!

   Customize the farewell message:

   java -jar target/myapp.jar goodbye --farewells "Farewell"
   

   Output: Farewell World!

5. Help and Version Information

   You can display help and version information with the following commands:

   Display help: java -jar target/myapp.jar --help

   Display version: java -jar target/myapp.jar --version