Screentime Monitor

A Java Spring Boot application that tracks and displays the screentime spent on each application or window on a Windows computer. It uses JNA to monitor active applications, logs screentime data, and provides a UI and REST API to view metrics.

Overview

• Track Active Applications: Utilizes JNA (Java Native Access) to call Windows API functions and identify the currently active application or window title.
• Record Screentime: Periodically logs the time spent on each application or window.
• Expose Metrics: Provides a Thymeleaf-based UI and a custom REST API to display screentime data.
• Installable App: Can be packaged as a JAR or EXE for easy deployment on Windows.

Step 1: Project Setup

Prerequisites

• Java Development Kit (JDK): Version 17 or later installed.
• Maven: Used as the build tool (Gradle is also an option).
• IDE: IntelliJ IDEA, Eclipse, or VS Code recommended.

Initial Setup

1. Create a Spring Boot project with dependencies: Spring Web, Spring Boot Actuator, Thymeleaf, Spring Data JPA, H2 Database, and JNA.
2. Configure the project using Maven (see pom.xml for details).

Run the Application

1. In your IDE, run the main class: ScreentimeMonitorApplication.java.
2. Open a browser or Postman and visit http://localhost:8080/ to view the Thymeleaf UI, or http://localhost:8080/screentime for raw metrics via the REST API.

Step 5: Make It Installable

Package as JAR

1. Run the following command to build the JAR:

   mvn clean package

2. Locate the JAR in the target/ folder (e.g., screentime-monitor-0.0.1-SNAPSHOT.jar).
3. Run it on Windows:

   java -jar screentime-monitor-0.0.1-SNAPSHOT.jar

Optional: Create an EXE

• Use Launch4j:
  1. Configure Launch4j to wrap the JAR into an .exe.
  2. Set it to run in the background (no console).
• Alternatively, use Inno Setup to create an installer that bundles the JAR and a startup script.

Run on Startup

• Add the JAR or EXE to the Windows Startup folder or registry:
  • Startup Folder: C:\Users\<YourUser>\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup.
  • Place the JAR/EXE or a shortcut there to launch on system boot.

Features

• Real-Time Tracking: Monitors active windows every second using JNA.
• Granular Metrics: Tracks screentime by window title (e.g., specific Chrome tabs or app instances).
• Persistent Data: Stores screentime data in an H2 database to retain metrics across restarts.
• User Interface: Displays a table of screentime metrics via a Thymeleaf-generated webpage at http://localhost:8080/.

Usage

1. Start the application using your IDE or the packaged JAR/EXE.
2. Use your computer normally—open applications, switch windows, etc.
3. Visit http://localhost:8080/ in a browser to see a table of screentime per application/window, updated in real-time.