Maven Project Setting the -source and -target of the Java Compiler

<project>
  [...]
  <properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>
  [...]
</project>

https://maven.apache.org/plugins/maven-compiler-plugin/examples/set-compiler-source-and-target.html