Correct the classpath of your application so that it contains compatible versions of the classes TomcatWebServerFactoryCustomizer

I have included tomcat in my pom

<dependencies>
    ...
    <dependency>
        <groupId>org.apache.tomcat.embed</groupId>
        <artifactId>tomcat-embed-core</artifactId>
        <version>8.5.32</version>
    </dependency>
</dependencies>

and when I run the spring boot application, I get the following message:

*************************** APPLICATION FAILED TO START

---

Description:

An attempt was made to call a method that does not exist. The attempt was made from the following location:

org.springframework.boot.autoconfigure.web.embedded.TomcatWebServerFactoryCustomizer.customizeMaxHttpRequestHeaderSize(TomcatWebServerFactoryCustomizer.java:264)

The following method did not exist:

'void org.apache.coyote.http11.AbstractHttp11Protocol.setMaxHttpRequestHeaderSize(int)'

The calling method's class, org.springframework.boot.autoconfigure.web.embedded.TomcatWebServerFactoryCustomizer, was loaded from the following location:

jar:file:/home/kamil/.m2/repository/org/springframework/boot/spring-boot-autoconfigure/3.1.0/spring-boot-autoconfigure-3.1.0.jar!/org/springframework/boot/autoconfigure/web/embedded/TomcatWebServerFactoryCustomizer.class

The called method's class, org.apache.coyote.http11.AbstractHttp11Protocol, is available from the following locations:

jar:file:/home/kamil/.m2/repository/org/apache/tomcat/embed/tomcat-embed-core/8.5.32/tomcat-embed-core-8.5.32.jar!/org/apache/coyote/http11/AbstractHttp11Protocol.class

The called method's class hierarchy was loaded from the following locations:

org.apache.coyote.http11.AbstractHttp11Protocol: file:/home/user/.m2/repository/org/apache/tomcat/embed/tomcat-embed-core/8.5.32/tomcat-embed-core-8.5.32.jar
org.apache.coyote.AbstractProtocol: file:/home/user/.m2/repository/org/apache/tomcat/embed/tomcat-embed-core/8.5.32/tomcat-embed-core-8.5.32.jar

Action:

Correct the classpath of your application so that it contains compatible versions of the classes org.springframework.boot.autoconfigure.web.embedded.TomcatWebServerFactoryCustomizer and org.apache.coyote.http11.AbstractHttp11Protocol

and when I remove it, the compiler doesn't see javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, and javax.servlet.http.FilterChain.

Remove the tomcat dependency. Spring Boot BOM is going to provide it for you. Change javax to jakarta as they were replaced in Spring Security 6.