use Netty as Sparkle runtime, within this environment you can't use any Servlet API.
Include 'org.agile:sparkle-netty:{version}' in your pom or gradle.
For Maven pom:
<dependency>
<groupId>org.agilej</groupId>
<artifactId>sparkle-netty</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
For gradle:
dependencies {
compile "org.agilej:sparkle-netty:1.0-SNAPSHOT"
}