SpringServletContainerInitializer cannot be cast to javax.servlet.ServletContainerInitializer

I am attempting to move a xml-based Spring MVC app to a Java Configuration based app. There appears to be a mismatch with the various java.servlet classes available in maven. For instance, some provide the addServlet() method and some do not.

Here is my config class:

public class MyWebAppInitializer implements WebApplicationInitializer {
    @Override
    public void onStartup(ServletContext container) throws ServletException {

        AnnotationConfigWebApplicationContext rootContext =
                new AnnotationConfigWebApplicationContext();
        rootContext.register(JpaSandboxConf.class);

        ServletRegistration.Dynamic registration = container.addServlet("dispatcher", new DispatcherServlet());
        registration.setLoadOnStartup(1);
        registration.addMapping("/myapp/*");
    }
}

Which seems rather uncontroversial. In order to get the

container.addServlet()

method, I included this in my pom:

<dependency>
    <groupId>org.apache.tomcat</groupId>
    <artifactId>tomcat-servlet-api</artifactId>
    <version>7.0.30</version>
</dependency>

I tried this, but the ServletContext class from the entry below DID NOT WORK (in that it didnot provide the addServlet() method):

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>com.springsource.javax.servlet</artifactId>
    <version>2.5.0</version>
    <scope>provided</scope>
</dependency>

When I attempt to run this using

mvn clean tomcat7:run

I unhappily obtain

SEVERE: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[/]]
    at java.