Deploy Your Java Application as an EXE File with Launch4J: A Detailed Guide

Learn how to successfully bundle your Java application into a Windows EXE file using Launch4J, ensuring a seamless deployment with JRE included.
---
This video is based on the question https://stackoverflow.com/q/75724428/ asked by the user 'Gabriele Passoni' ( https://stackoverflow.com/u/17043505/ ) and on the answer https://stackoverflow.com/a/75735063/ provided by the user 'life888888' ( https://stackoverflow.com/u/20306007/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Java - Deployment of an exe bundled with JRE using Launch4J

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Deploy Your Java Application as an EXE File with Launch4J: A Detailed Guide

If you've just wrapped up your Java project and are eager to share it with the world, you may be wondering how to deploy it properly for Windows users. The challenge often lies in making sure your application can run smoothly on any machine without requiring extensive installations, especially when it comes to Java Runtime Environment (JRE). In this guide, we'll address how to convert your Java application into a standalone Windows EXE file using Launch4J and bundle it with the necessary JRE.

Understanding the Problem

Java applications typically run on any machine with the correct version of JRE installed. However, for ease of deployment, it's essential to create an executable that can run independently, without requiring users to manually install Java. Below are the key issues faced during this process:

JAR File Does Not Run on Double Click: Your JAR file may not execute with a double click, hinting at potential path issues, or that it defaults to using javaw instead of java.

EXE File Behavior: Your generated EXE might show a command prompt flash and then disappear, indicating that the application is failing to run—usually due to a missing JRE.

JRE Accessibility: Confusion persists regarding where to locate the JRE within the installed JDK, as some distributions may not include it directly.

Bundling Requirements: You want the EXE file bundled with a JRE version so that other users can run your application without any extra installations.

The Solution: Packaging Your Java Application with Launch4J

Initial Steps

Before diving into Launch4J, ensure you have the necessary tools installed on your system:

JDK 19: Make sure you have the right JDK version downloaded—OpenJDK 19 is a good option.

Launch4J: Download and set up Launch4J, which is the tool that will help you wrap your JAR in an EXE file.

Find Your Application Dependencies

Use the following command to analyze your JAR file and list its dependencies:

[[See Video to Reveal this Text or Code Snippet]]

This command lets you specify the classpaths and will help in determining which modules are required by your application. For applications without dependencies, simply use:

[[See Video to Reveal this Text or Code Snippet]]

Building a Slim JRE

Next, we will create a minimized JRE that includes only the necessary modules for your application:

[[See Video to Reveal this Text or Code Snippet]]

This command will create a compact JRE tailored for your specific application needs.

Organize Your Project Structure

Your project directory should ideally look like this:

[[See Video to Reveal this Text or Code Snippet]]

Configuring Launch4J

Open Launch4J and set up your project as follows:

Basic Tab:

Output file: Path where your EXE will be stored (e.g., C:\Path\To\Output\demoapp.exe)

Jar: Path to your JAR file.

Header Tab:

Header type: Set to GUI.

JRE Tab:

Bundled JRE paths: Specify the directory path (e.g., jre).

Only use private JDK runtimes: Tick this option.

Saving and Compiling

Your demoapp.xml configuration should look like this:

[[See Video to Reveal this Text or Code Snippet]]

Final Steps

Once your configuration is set, click on the Build button in Launch4J to create the EXE. Ensure that the resulting structure inside your output folder contains both the EXE file and the jre folder.

Distribution

To share your application effortlessly, package the demoapp.exe and the jre folder into a zip file. When distributed, users should be able to run the EXE directly without needing to install JRE separately.

Conclusion

Converting your Java application into an EXE with bundled JRE using Launch4J can seem daunting in