Interactive Java consoles with JLine and ConsoleUI

JLine and ConsoleUI are libraries in Java that provide functionality for creating interactive console applications. Let's go through a brief overview of each library and how to use them:

1. JLine: JLine is a Java library that provides support for handling console input and output in a more interactive manner. It allows you to read user input, provide command-line editing, history management, and tab-completion, making it suitable for building command-line applications that offer a better user experience.

To use JLine, you typically need to add the JLine dependency to your project using a build tool like Maven or Gradle. Here's an example of how to use JLine in a basic interactive Java console application:

Step 1: Add the JLine dependency to your Maven project (pom.xml):

xml
<dependency>
    <groupId>org.jline</groupId>
    <artifactId>jline</artifactId>
    <version>3.19.0</version> <!-- Replace with the latest version available -->
</dependency>        

Step 2: Write a simple Java program using JLine:

java
import org.jline.reader.*;
import org.jline.reader.impl.DefaultParser;
import org.jline.reader.impl.LineReaderImpl;
import org.jline.terminal.Terminal;
import org.jline.terminal.TerminalBuilder;

public class JLineExample {
    public static void main(String[] args) {
        try {
            Terminal terminal = TerminalBuilder.terminal();
            LineReader lineReader = new LineReaderImpl(terminal);
            
            String prompt = "Enter your name: ";
            String name = lineReader.readLine(prompt);
            
            System.out.println("Hello, " + name + "!");
            
            terminal.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}        

When you run this program, it will display a prompt for the user to enter their name and then greet them with the entered name.

1. ConsoleUI: ConsoleUI is another Java library that provides higher-level abstractions for creating console-based user interfaces. It simplifies the creation of interactive menus, dialogs, and screens for text-based applications.

To use ConsoleUI, you also need to add the ConsoleUI dependency to your project using a build tool like Maven or Gradle. Here's an example of how to use ConsoleUI to create a simple interactive menu:

Step 1: Add the ConsoleUI dependency to your Maven project (pom.xml):

xml
<dependency>
    <groupId>com.googlecode.lanterna</groupId>
    <artifactId>console-ui</artifactId>
    <version>3.5.2</version> <!-- Replace with the latest version available -->
</dependency>        

Step 2: Write a simple Java program using ConsoleUI:

java
import com.googlecode.lanterna.*;
import com.googlecode.lanterna.gui2.*;

public class ConsoleUIExample {
    public static void main(String[] args) {
        try {
            DefaultTerminalFactory terminalFactory = new DefaultTerminalFactory();
            Terminal terminal = terminalFactory.createTerminal();
            Screen screen = new TerminalScreen(terminal);
            screen.startScreen();
            
            Panel contentPanel = new Panel();
            contentPanel.setLayoutManager(new LinearLayout(Direction.VERTICAL));
            contentPanel.addComponent(new Label("Welcome to ConsoleUI!"));
            contentPanel.addComponent(new EmptySpace(new TerminalSize(0, 1)));
            contentPanel.addComponent(new Label("1. Option 1"));
            contentPanel.addComponent(new Label("2. Option 2"));
            contentPanel.addComponent(new EmptySpace(new TerminalSize(0, 1)));
            contentPanel.addComponent(new Label("Choose an option:"));
            
            BasicWindow window = new BasicWindow();
            window.setComponent(contentPanel);
            MultiWindowTextGUI textGUI = new MultiWindowTextGUI(screen, new DefaultWindowManager(), new EmptySpace(TextColor.ANSI.BLUE));
            textGUI.addWindowAndWait(window);
            
            screen.stopScreen();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}        

When you run this program, it will display a simple menu with two options. The user can select an option by typing the corresponding number.

Please note that the version numbers mentioned in the examples may become outdated over time, so it's essential to check for the latest versions of JLine and ConsoleUI libraries and update your dependencies accordingly.

Remember that interactive console applications are limited to the capabilities of the console environment, so they may not provide the same level of interactivity and visual richness as graphical user interfaces. However, they are handy for text-based applications and command-line tools that require user input and interaction.