The type javax.servlet.ServletContext and javax.servlet.ServletException cannot be resolved

Just add the javax.servlet API to the compile time dependencies. You don't need to include it in the build, it's already provided by the target servlet container.

Your current pom suggests that you're deploying to a barebones servlet container (Tomcat, Jetty, etc) instead of a full fledged Java EE application server (WildFly, TomEE, GlassFish, Liberty, etc), otherwise you'd have run into classloading-related trouble by providing JSF along with the webapp instead of using the container-provided one.

In that case, adding the below dependency should do for a Servlet 3.1 container like Tomcat 8:

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.1.0</version>
    <scope>provided</scope>
</dependency>

Or if you're actually targeting an older Servlet 3.0 container like Tomcat 7, change the <version> to 3.0.1 (note: there's no 3.0 due to a mistake on their side).

If you happen to actually deploy to a Java EE 7 application server like WildFly 8, use the below dependency instead. It covers the entire Java EE API, including javax.servlet (and javax.faces, so you'd then remove those individual JSF API/impl dependencies):

<dependency>
    <groupId>javax</groupId>
    <artifactId>javaee-api</artifactId>
    <version>7.0</version>
    <scope>provided</scope>
</dependency>

Also here, if you're targeting an older Java EE 6 application server like JBoss AS 7, change the <version> to 6.0.

This worked for me: if above supplied solution doesnt work Project > Properties > Java Build Path > Libraries > Add library from library tab > Choose server runtime > Next > choose Apache Tomcat v 7.0> Finish > Ok

another way if you working on eclipse ide please open the project folder select Properties and click maven shows the view 'Active Maven Profiles(comma separated)'please input "dev"..after refresh problem solved