The example uses GNU gcj to generate native executable from java source.
Note:
<project>
[...]
<packaging>uexe</packaging>
[...]
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>native-maven-plugin</artifactId>
<extensions>true</extensions>
<configuration>
<compilerExecutable>gcj</compilerExecutable>
<compilerOutputDirectory}${project.build.directory}/objs</compilerOutputDirectory>
<sources>
<source>
<directory>src/main/java</directory>
<includes>
<include>**/*.java</include>
</includes>
</source>
</sources>
<compilerStartOptions>
<compilerStartOption>-O2</compilerStartOption>
</compilerStartOptions>
<linkerExecutable>gcj</linkerExecutable>
<linkerStartOptions>
<linkerStartOption>--main=full.class.name</linkerStartOption>
</linkerStartOptions>
</configuration>
</plugin>
</plugins>
</build>
</project>