Packaging up applications written in Java to run stand alone has never been easier thanks to JavaPackager.

The Application

Again we’ll be using my snake game written in Java.

JavaPackager

JavaPackager is a Gradle/Maven plugin that automates the complete packaging of applications in Linux, Mac and Windows. We’ll be using it to create a .dmg containing our game (and runtime) that should allow for easy installation into Mac’s Applications directory.

Including the plugin

Adding the dependency for JavaPackager couldn’t be simpler, we simply add the following to our pom.xml

    <dependency>
      <groupId>io.github.fvarrui</groupId>
      <artifactId>javapackager</artifactId>
      <version>1.2.0</version>
    </dependency>

Configuring the plugin

The README included on the JavaPackager GitHub includes examples of how to configure JavaPackager. I’ve chosen to adopt the follow config

<plugin>
        <groupId>io.github.fvarrui</groupId>
        <artifactId>javapackager</artifactId>
        <version>1.2.0</version>
        <executions>
          <execution>
            <phase>package</phase>
            <id>make_dmg</id>
            <goals>
              <goal>package</goal>
            </goals>
            <configuration>
              <name>Snake</name>
              <mainClass>com.gregory.learning.App</mainClass>
              <bundleJre>true</bundleJre>
              <jrePath>A_MAC_JDK</jrePath>
            </configuration>
          </execution>
          <execution>
            <phase>package</phase>
            <id>make_windows</id>
            <goals>
              <goal>package</goal>
            </goals>
            <configuration>
              <name>Snake</name>
              <mainClass>com.gregory.learning.App</mainClass>
              <bundleJre>true</bundleJre>
              <jrePath>A_WINDOWS_JDK</jrePath>
              <platform>windows</platform>
            </configuration>
          </execution>
        </executions>
      </plugin>

I have configured two executions which will in turn create a Windows executable and a Mac .dmg. Unfortunately as I’m building from Mac the plugin is unable to generate an MSI. I’ve chosen to bundle a JRE in both cases as this makes it easier for the user to run the application.

Including assets

Adding assets to be included with the final package is also straightforward. By default the plugin searches for a directory called assets located at project level. I’ve used this to include an icon for the game.

Creating the packages

We’ve bound the plugin to the package phase so running mvn clean package should generate our executables/disk images! The target folder now contains the .dmg and .exe. Mounting the image works the same as any other Mac application and launching it from launchpad is as easy a single click. Find the .dmg amongst the other Snake releases here.