If you are asking for how to specify the dependency on Commons-IO in the pom.xml:

    <dependency>
        <groupId>commons-io</groupId>
        <artifactId>commons-io</artifactId>
        <version>2.1</version>
    </dependency>

MoJoExecutionException is exceptions by maven plugins to signle something is wrong. reading you error stacktrace looks like your tomcat plugin is complaining about class not found at runtime.

can you please share your complete pom.xml. Have you added tomcat plugin ?

Also add below dependency

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-io</artifactId>
    <version>1.3.2</version>
</dependency>

Version 1.3.2 doesn't have this method, use a newer version of commons-io

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.4</version>
</dependency>

Check the FileUtils 2.4 javadoc

If it compiles fine but throws the exception when running, it means the dependency was on classpath when compiling but not when running the code.

Maven is responsible for compile classpath, and did provide the dependency on compile time. You'll have to check how you run the application and make sure the maven dependencies are also on the runtime classpath - that has nothing to do with Maven, unless you run the code as a part of unit tests.