Spring Boot java.lang.NoClassDefFoundError: javax/servlet/Filter

for the maven users, comment the scope provided in the following dependency:

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-tomcat</artifactId>
        <!--<scope>provided</scope>-->
    </dependency>

UPDATE

As feed.me mentioned you have to uncomment the provided part depending on what kind of app you are deploying.

Here is a useful link with the details: http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#build-tool-plugins-maven-packaging

providedRuntime("org.springframework.boot:spring-boot-starter-tomcat")

This should be

compile("org.springframework.boot:spring-boot-starter-tomcat")

It's not good to change the scope of your application dependencies. Putting the dependency as compile, will provide the dependency also in your artifact that will be installed somewere. The best think to do is configure the RUN configuration of your sping boot application by specifying as stated in documentation :

"Include dependencies with 'Provided' scope" "Enable this option to add dependencies with the Provided scope to the runtime classpath."