org.springframework.boot.web.support does not exist

You are using org.springframework.boot.context.web.SpringBootServletInitializer this is deprecated. Instead:

Use

org.springframework.boot.web.support.SpringBootServletInitializer

For SpringBoot 2.0

org.springframework.boot.web.servlet.support.SpringBootServletInitializer

It's probably an import issue in your source code - your Gradle build script uses Spring Boot 1.3.6.RELEASE in which SpringBootServletInitializer has the following fully qualified name:

org.springframework.boot.context.web.SpringBootServletInitializer 

Your Maven pom.xml, however, uses Spring Boot 1.4.0.BUILD-SNAPSHOT, in which the package name was changed to:

org.springframework.boot.web.support.SpringBootServletInitializer

So if you go to your SampleJettyJspApplication and change the import to

import org.springframework.boot.context.web.SpringBootServletInitializer;

everything should be fine.

Alternatively, you could alter your Gradle build script to import 1.4.0.BUILD-SNAPSHOT, but that would require adding Spring's snapshot repository:

buildscript {
    repositories {
        maven.url "http://repo.spring.io/snapshot"
        mavenCentral()
    }

    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.4.0.BUILD-SNAPSHOT")
    }
}