maven-compiler-plugin it's already present in plugins hierarchy dependency in pom.xml. Check in Effective POM.
For short you can use properties like this:
<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
I'm using Maven 3.2.5.
~ Answered on 2015-07-28 11:54:32