ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean

Question

Case 1:

@SpringBootApplication annotation missing in your spring boot starter class.

Case 2:

For non-web applications, disable web application type in the properties file.

In application.properties:

spring.main.web-application-type=none

If you use application.yml then add:

  spring:
    main:
      web-application-type: none

For web applications, extends *SpringBootServletInitializer* in the main class.

@SpringBootApplication
public class YourAppliationName extends SpringBootServletInitializer{
    public static void main(String[] args) {
        SpringApplication.run(YourAppliationName.class, args);
    }
}

Case 3:

If you use spring-boot-starter-webflux then also add spring-boot-starter-web as dependency.

Probably you missing @SpringBootApplication in your spring boot starter class.

@SpringBootApplication
public class LoginSecurityAppApplication {

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

}

The solution is:

I explicitly set the below property to none in application.yml file.

spring:
  main:
    web-application-type: none

My solution had to do with a bad dependency. I had:

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-web</artifactId>
  <exclusions>
    <exclusion>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-tomcat</artifactId>
    </exclusion>
  </exclusions>
</dependency>

In my pom and I had to comment out the exclusion to get it working. It must look for this tomcat package for some reason.

You probably use this in your project:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-webflux</artifactId>
</dependency>

in which case you'll have to also add:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

and the magic happens :)

PS: that's because Spring will use by default web-MVC instead of web-flux when both are available

In my case the issue resolved on commenting the tomcat dependencies exclusion from spring-boot-starte-web

     <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <!-- <exclusions>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-tomcat</artifactId>
            </exclusion>
        </exclusions> -->
    </dependency>