<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.7</source> <!-- yours Java version -->
<target>1.7</target> <!-- yours Java version -->
</configuration>
</plugin>
</plugins>
</build>