flatpak-maven-plugin

A fork of maven-flatpak-plugin by Brett Smith.

This plugin builds flatpak artifacts from a Java project including a .flatpak application which can be installed via GNOME Software.

It depends on several standard pom properties and the rest provided in a plugin configuration.

See my Journal project's pom.xml for full example usage (also listed below). It's only been tested with the Journal project so feedback in other contexts would be appreciated.

Maven Goals

Three goals are provided:

1. prepare-build - Generate flatpak artifacts required for flatpak-builder.
2. build-repo - Calls flatpak-builder to create a flatpak repository from the prepared artifacts.
3. export-flatpak - Calls flatpak to build a .flatpak bundle from the repo.

The actual commands run for the last two goals are provided in the log.

Usage

This plugin has not yet been released to Maven Central. In the meantime it can be found in the snapshots repository. Add the following to your root of your pom.xml:

<pluginRepositories>
    <pluginRepository>
        <id>central-snapshots</id>
        <url>https://central.sonatype.com/repository/maven-snapshots/</url>
        <snapshots>
            <enabled>true</enabled>
        </snapshots>
    </pluginRepository>
</pluginRepositories>

And in your <build> section:

<plugin>
    <groupId>ca.footeware</groupId>
    <artifactId>flatpak-maven-plugin</artifactId>
    <version>1.2.0-SNAPSHOT</version>
    <executions>
        <execution>
            <id>prepare</id>
            <phase>package</phase>
            <goals>
                <goal>prepare-build</goal>
                <goal>build-repo</goal>
                <goal>export-flatpak</goal>
            </goals>
            <configuration>
                <!-- required parameters, see below -->
            </configuration>
        </execution>
    </executions>
</plugin>

Configure The Plugin

A lot of the required parameters are taken from the stock pom properties. The rest are provided explicitly in the plugin's configuration block. For example the pom.xml of the Journal application mentioned above:

<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>ca.footeware.javagi</groupId>
    <artifactId>journal</artifactId>
    <version>1.0.0-SNAPSHOT</version>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>25</maven.compiler.source>
        <maven.compiler.target>25</maven.compiler.target>
    </properties>

    <dependencies>
        <!--Java on Gtk4/Adw-->
        <dependency>
            <groupId>org.java-gi</groupId>
            <artifactId>adw</artifactId>
            <version>0.13.0</version>
        </dependency>
    </dependencies>

    <build>
        <resources>
            <resource>
                <directory>src/main/resources/</directory>
            </resource>
            <resource>
                <!--project.properties needs string injection or filtering-->
                <directory>src/main/resources/filtered</directory>
                <includes>
                    <include>project.properties</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>

        <plugins>
            <!--project.properties above needs to be handled in UTF-8-->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <version>3.3.1</version>
                <configuration>
                    <propertiesEncoding>UTF-8</propertiesEncoding>
                </configuration>
            </plugin>

            <!--The initialize phase is early, before package. Here we are compiling a gresource file-->
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>3.6.2</version>
                <executions>
                    <execution>
                        <id>gresource-compiling</id>
                        <phase>initialize</phase>
                        <goals>
                            <goal>exec</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <executable>/usr/bin/glib-compile-resources</executable>
                    <workingDirectory>${project.basedir}/src/main/resources/</workingDirectory>
                    <commandlineArgs>${project.basedir}/src/main/resources/journal.gresource.xml</commandlineArgs>
                </configuration>
            </plugin>

            <plugin>
                <groupId>ca.footeware</groupId>
                <artifactId>flatpak-maven-plugin</artifactId>
                <version>1.2.0-SNAPSHOT</version>
                <executions>
                    <execution>
                        <id>prepare</id>
                        <phase>package</phase>
                        <goals>
                            <goal>prepare-build</goal>
                            <goal>build-repo</goal>
                            <goal>export-flatpak</goal>
                        </goals>
                        <configuration>
                            <mainClass>ca.footeware.javagi.journal.JournalApplication</mainClass>
                            <usingModules>false</usingModules>
                            <runtime>org.gnome.Platform</runtime>
                            <sdk>org.gnome.Sdk</sdk>
                            <runtimeVersion>49</runtimeVersion>
                            <categories>Office;Calendar</categories>
                            <iconPath>src/main/resources/journal.svg</iconPath>
                            <gschemaPath>src/main/resources/ca.footeware.javagi.journal.gschema.xml</gschemaPath>
                            <startupWMClass>ca.footeware.javagi.journal</startupWMClass>
                            <screenshots>
                                <screenshot>
                                    <image>
                                        <type>source</type>
                                        <!--must be absolute URL-->
                                        <value>https://raw.githubusercontent.com/CraigFoote/ca.footeware.javagi.journal/refs/heads/master/src/main/resources/screenshots/screenshot1.png</value>
                                    </image>
                                    <caption>Journal initial page</caption>
                                    <type>default</type> <!--only one of type default-->
                                </screenshot>
                                <screenshot>
                                    <image>
                                        <type>source</type>
                                        <value>https://raw.githubusercontent.com/CraigFoote/ca.footeware.javagi.journal/refs/heads/master/src/main/resources/screenshots/screenshot2.png</value>
                                    </image>
                                    <caption>Create a new journal page</caption>
                                </screenshot>
                                <screenshot>
                                    <image>
                                        <type>source</type>
                                        <value>https://raw.githubusercontent.com/CraigFoote/ca.footeware.javagi.journal/refs/heads/master/src/main/resources/screenshots/screenshot3.png</value>
                                    </image>
                                    <caption>Open a journal page</caption>
                                </screenshot>
                                <screenshot>
                                    <image>
                                        <type>source</type>
                                        <value>https://raw.githubusercontent.com/CraigFoote/ca.footeware.javagi.journal/refs/heads/master/src/main/resources/screenshots/screenshot4.png</value>
                                    </image>
                                    <caption>Journal editor page</caption>
                                </screenshot>
                            </screenshots>
                            <branding>
                                <colors>
                                    <color>
                                        <type>primary</type>
                                        <schemePreference>light</schemePreference>
                                        <value>#d8dee9</value>
                                    </color>
                                    <color>
                                        <type>primary</type>
                                        <schemePreference>dark</schemePreference>
                                        <value>#4c566a</value>
                                    </color>
                                </colors>
                            </branding>
                            <!--https://hughsie.github.io/oars/generate.html-->
                            <contentRating>
                                <type>oars-1.1</type>
                            </contentRating>
                            <vmArgs>
                                <vmArg>--enable-native-access=ALL-UNNAMED</vmArg>
                            </vmArgs>
                            <releases>
                                <release>
                                    <version>1.0.0</version>
                                    <date>2025-12-01</date>
                                    <!--descriptions must contain <p>, <ul> and <li> tags in CDATA block.-->
                                    <!--see https://www.freedesktop.org/software/appstream/docs/chap-Metadata.html#tag-description-->
                                    <description><![CDATA[
                                    <p>Initial release</p>
                                    <ul>
                                        <li>Feature complete</li>
                                    </ul>
                                    ]]></description>
                                </release>
                            </releases>
                            <manifest>
                                <appId>ca.footeware.javagi.journal</appId>
                                <sdkExtensions>
                                    <sdkExtension>org.freedesktop.Sdk.Extension.openjdk25</sdkExtension>
                                </sdkExtensions>
                                <finishArgs>
                                    <finishArg>--socket=session-bus</finishArg>
                                    <finishArg>--socket=wayland</finishArg>
                                    <finishArg>--device=dri</finishArg>
                                    <finishArg>--share=ipc</finishArg>
                                    <finishArg>--filesystem=home</finishArg>
                                    <finishArg>--env=PATH=/app/jre/bin:/app/bin:/usr/bin</finishArg>
                                    <finishArg>--env=JAVA_HOME=/app/jre</finishArg>
                                </finishArgs>
                            </manifest>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

    <name>Journal</name>

    <description>An encrypted daily journal. Password-encrypted and navigable via a built-in calendar. It uses a local text file in properties format where the keys are dates and the values are encrypted.</description>

    <url>https://github.com/CraigFoote/ca.footeware.javagi.journal</url>

    <inceptionYear>2025</inceptionYear>

    <organization>
        <name>Footeware.ca</name>
        <url>https://footeware.ca</url>
    </organization>

    <scm>
        <url>https://github.com/CraigFoote/ca.footeware.javagi.journal</url>
        <connection>scm:git:https://github.com/CraigFoote/ca.footeware.javagi.journal.git</connection>
        <developerConnection>scm:git:https://github.com/CraigFoote/ca.footeware.javagi.journal.git</developerConnection>
    </scm>

    <issueManagement>
        <url>https://github.com/CraigFoote/ca.footeware.javagi.journal/issues</url>
        <system>Github</system>
    </issueManagement>

    <!--necessary until flatpak-maven-plugin is released-->
    <pluginRepositories>
        <pluginRepository>
            <id>central-snapshots</id>
            <url>https://central.sonatype.com/repository/maven-snapshots/</url>
            <snapshots>
                <enabled>true</enabled>
            </snapshots>
        </pluginRepository>
    </pluginRepositories>

    <!--must be included for flatpak plugin -->
    <!--See https://spdx.org/licenses/-->
    <licenses>
        <license>
            <name>GPL-3.0-or-later</name>
            <url>https://spdx.org/licenses/GPL-3.0-or-later.html</url>
            <distribution>repo</distribution>
            <comments>project</comments>
        </license>
        <!--defaults to FSFAP if omitted -->
        <license>
            <name>FSFAP</name>
            <url>https://spdx.org/licenses/FSFAP.html</url>
            <distribution>repo</distribution>
            <comments>metadata</comments>
        </license>
    </licenses>

    <!--must be included for flatpak plugin -->
    <developers>
        <developer>
            <!--must be reverse DNS notation-->
            <id>ca.footeware.craigfoote</id> <!--required-->
            <name>Craig Foote</name> <!--required-->
            <email>CraigFoote@gmail.com</email> <!--optional-->
            <url>https://github.com/CraigFoote</url> <!--optional-->
            <organization>Footeware</organization> <!--optional-->
            <organizationUrl>https://footeware.ca</organizationUrl> <!--optional-->
            <roles><!--optional-->
                <role>developer</role>
            </roles>
            <timezone>America/Toronto</timezone> <!--optional-->
        </developer>
    </developers>
</project>

TODO

• Site development.
• Investigate and release the plugin to maven central.

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