The Compiler Plugin is used to compile the sources of your project.
At present the default source setting is 1.5 and the default target setting is 1.5, independently of the JDK you run Maven with.
Change these defaults：
<project> [...] <build> [...] <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.3</version> <configuration> <source>1.7</source> <target>1.7</target> </configuration> </plugin> </plugins> [...] </build> [...] </project>
原文：http://www.cnblogs.com/zno2/p/4583178.html