Application fails to load when main class extends a base class annotated with @SpringBootApplication when spring-boot-starter-web is included as a dependency #19141
Description
Application fails to start due to missing ServletWebServerFactory bean after upgrading spring boot starter parent to 2.2.1.RELEASE from 2.1.7.RELEASE. This is happening only when we use
spring-boot-starter-web as a dependency and make the main application class extend a base class annotated with SpringBootApplication. There is no issue when NOT using spring-boot-starter-web and using spring-boot instead.
Base Class:
package com.example.demo;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public abstract class AppBase {
}
Main Class:
package com.example.demo;
import org.springframework.boot.SpringApplication;
public class DemoApplication extends AppBase {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
Problem POM:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>demo2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>demo2</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
</project>
Working POM:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>demo2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>demo2</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot</artifactId>
</dependency>
</dependencies>
</project>
We can reproduce the issue by including this dependency also,
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
</dependency>
This particular example throws,
org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.context.ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean.
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:156) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544) ~[spring-context-5.2.1.RELEASE.jar:5.2.1.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at com.example.demo.DemoApplication.main(DemoApplication.java:8) ~[classes/:na]
Caused by: org.springframework.context.ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean.
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.getWebServerFactory(ServletWebServerApplicationContext.java:203) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:179) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:153) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
... 8 common frames omitted
Our actual application threw a completely different exception that led us to find the issue:
java.lang.IllegalArgumentException: No auto-configuration attributes found. Is n annotated with EnableAutoConfiguration?
at org.springframework.util.Assert.notNull(Assert.java:215) ~[spring-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector.getAttributes(AutoConfigurationImportSelector.java:148) ~[spring-boot-autoconfigure-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector.getAutoConfigurationEntry(AutoConfigurationImportSelector.java:115) ~[spring-boot-autoconfigure-2.2.1.RELEASE.jar:2.2.1.RELEASE]
..........................................
..............................................