Java 16 Packaging Tool (Incubator, JEP 391)

Java 16 introduced an incubator module for the Packaging Tool, which is a new tool that allows you to package your Java applications as native executables for multiple platforms. The Packaging Tool is designed to make it easy to create self-contained, native executables that can be distributed and run on different systems without the need for a Java runtime or a pre-installed Java application.

Here is an example of how to use the Packaging Tool to package a simple Java application as a native executable:

// Create a simple Java application
class HelloWorld {
  public static void main(String[] args) {
    System.out.println("Hello, World!");
  }
}

// Compile the application
javac HelloWorld.java

// Package the application as a native executable
jpackage --name HelloWorld --input . --main-class HelloWorld

In this example, we are using the jpackage command to package the HelloWorld application as a native executable. We are using the --name option to specify the name of the executable, the --input option to specify the input directory containing the compiled classes, and the --main-class option to specify the main class of the application.

The Packaging Tool can also be used to package more complex applications, such as applications that depend on external libraries or that require special runtime options. It supports a variety of platforms and formats, such as Windows MSI installers, macOS DMG files, and Linux DEB and RPM packages.

One important thing to note about the Packaging Tool is that it is currently an incubator module, which means that it is experimental and may change in future releases. It is also subject to additional restrictions and requirements, such as the need to enable the module explicitly and the need to comply with the terms of the Packaging Tool incubator module license.