java.lang.ClassNotFoundException: org.apache.jsp.index_jsp

It's been a while since I posted this, but I thought I would show how I figured it out (as best as I recall now).

I did a Maven dependency tree to find dependency conflicts, and I removed all conflicts with exclusions in dependencies, e.g.:

<dependency>
    <groupId>commons-logging</groupId>
    <artifactId>commons-logging-api</artifactId>
    <version>1.1</version>
    <exclusions>
        <exclusion>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
        </exclusion>
    </exclusions>
</dependency>

Also, I used the provided scope for javax.servlet dependencies so as not to introduce an additional conflict with what is provided by Tomcat when I run the app.

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>servlet-api</artifactId>
    <version>2.5</version>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>javax.servlet.jsp</groupId>
    <artifactId>jsp-api</artifactId>
    <version>2.1</version>
    <scope>provided</scope>
</dependency>

HTH.

An addition to the other answers that didn't work for me: In my case the error occurred due to permission errors. The project got deployed while the tomcat was running as root, later when started as tomcat user I got the error from the question title.

Solution in my case was to set the right permissions, e.x. on a unix system:

cd <tomcat-dir>
chown -R <tomcat-user> *