There is a configuration element in the PMD plugin that let you set which target JDK to use. Often you want this to be in sync with the configuration for maven-compiler-plugin. The best practice for this is to set up a property and use that in the configuration section for each of the plugins. Here is an example on how to set that up:
<project> ... <build> <plugins> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>2.0.2</version> <configuration> <source>${compileSource}</source> </configuration> </plugin> </plugins> </build> ... <reporting> <plugins> <plugin> <artifactId>maven-pmd-plugin</artifactId> <version>3.2</version> <configuration> <targetJdk>${compileSource}</targetJdk> </configuration> </plugin> </plugins> </reporting> ... <properties> <compileSource>1.5</compileSource> </properties> ... </project>