spring-boot-starter-jetty 1.4.x.RELEASE missing EmbeddedServletContainerFactory

Question

When using the following gradle configuration:

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.4.1.RELEASE")
    }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'spring-boot'

jar {
    baseName = 'gs-starter-app'
    version =  '0.1.0'
}

sourceCompatibility = 1.7
targetCompatibility = 1.7

repositories {
    mavenCentral()
}

configurations {
    compile.exclude module: "spring-boot-starter-tomcat"
    compile.exclude module: "spring-boot-starter-logging"
}

dependencies {
    compile("org.springframework.boot:spring-boot-starter-web:1.4.1.RELEASE")
    compile("org.springframework.boot:spring-boot-starter-actuator:1.4.1.RELEASE")
    compile("org.springframework.boot:spring-boot-starter-jetty:1.4.1.RELEASE")
    compile('org.springframework.boot:spring-boot-starter-log4j2:1.4.1.RELEASE')
    testCompile("org.springframework.boot:spring-boot-starter-test:1.4.1.RELEASE")
    testCompile("junit:junit")
}
```
The app won't start up, the exception being:
```
2016-11-07 09:36:22.900 ERROR 44150 --- [           main] o.s.b.SpringApplication                  : Application startup failed

org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.context.ApplicationContextException: Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean.
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:137) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:535) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at com.mystuff.Application.main(Application.java:10) [main/:?]
Caused by: org.springframework.context.ApplicationContextException: Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean.
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.getEmbeddedServletContainerFactory(EmbeddedWebApplicationContext.java:189) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:162) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:134) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    ... 8 more

Note: I've also tried this with 1.4.0. But when I backtrack to an 1.3.x.RELEASE it all works:

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.3.8.RELEASE")
    }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'spring-boot'

jar {
    baseName = 'gs-starter-app'
    version =  '0.1.0'
}

sourceCompatibility = 1.7
targetCompatibility = 1.7

repositories {
    mavenCentral()
}

configurations {
    compile.exclude module: "spring-boot-starter-tomcat"
    compile.exclude module: "spring-boot-starter-logging"
}

dependencies {
    compile("org.springframework.boot:spring-boot-starter-web:1.3.8.RELEASE")
    compile("org.springframework.boot:spring-boot-starter-actuator:1.3.8.RELEASE")
    compile("org.springframework.boot:spring-boot-starter-jetty:1.3.8.RELEASE")
    compile('org.springframework.boot:spring-boot-starter-log4j2:1.3.8.RELEASE')
    testCompile("org.springframework.boot:spring-boot-starter-test:1.3.8.RELEASE")
    testCompile("junit:junit")
}

My application class looks like this:

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class);
    }

}

Googling around shows that the most common reasons for this are:

1. A missing spring-boot-starter-web dependency - not the case here
2. A missing maven plugin - not appropriate here

Why is this happening?

Answer 1

1.4.x uses Jetty 9.3 which requires java 8

I see in your build script that your are using Java 7. Spring Boot 1.4.x uses Jetty 9.3, which requires java 8 (see Spring Boot's Jetty vs Java versions)

Java 7 - Fallback to Jetty 9.2

If upgrading to Java 8 is not an option, you need to use Jetty 9.2 instead (see how-to-use-jetty-9.2-gradle). This can be done by redefining the property jetty.version:

ext['jetty.version'] = '9.2.17.v20160517'
dependencies {
    compile ('org.springframework.boot:spring-boot-starter-web') {
        exclude group: 'org.springframework.boot', module: 'spring-boot-starter-tomcat'
    }
    compile ('org.springframework.boot:spring-boot-starter-jetty')
}