Exclude tomcat dependency from maven when building

Question

I am working on a Spring Boot 3.4.0 application configured as a WAR for deployment on WildFly 34. After several attempts, I successfully excluded conflicting dependencies (like embedded Tomcat and logging), and the WAR now deploys correctly on WildFly.

This is my pom.xml:

<?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>3.4.0</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.reportplanner</groupId>
    <artifactId>ReportPlanner</artifactId>
    <version>1</version>
    <packaging>war</packaging>
    <name>ReportPlanner</name>
    <description>Report Planner Web Application: Backend Service</description>
    <url/>
    <licenses>
        <license/>
    </licenses>
    <developers>
        <developer/>
    </developers>
    <scm>
        <connection/>
        <developerConnection/>
        <tag/>
        <url/>
    </scm>
    <properties>
        <java.version>17</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>ch.qos.logback</groupId>
                    <artifactId>logback-classic</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>ch.qos.logback</groupId>
                    <artifactId>logback-classic</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-logging</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>ch.qos.logback</groupId>
                    <artifactId>logback-classic</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>ch.qos.logback</groupId>
                    <artifactId>logback-core</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-autoconfigure</artifactId>
            <version>3.4.0</version>
        </dependency>
        <dependency>
            <groupId>org.jboss.slf4j</groupId>
            <artifactId>slf4j-jboss-logmanager</artifactId>
            <version>2.0.1.Final</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springdoc</groupId>
            <artifactId>springdoc-openapi-starter-webmvc-ui</artifactId>
            <version>2.6.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.jackrabbit</groupId>
            <artifactId>jackrabbit-webdav</artifactId>
            <version>2.22.0</version>
        </dependency>
        <dependency>
            <groupId>commons-httpclient</groupId>
            <artifactId>commons-httpclient</artifactId>
            <version>3.1</version>
        </dependency>
        <dependency>
            <groupId>com.github.lookfirst</groupId>
            <artifactId>sardine</artifactId>
            <version>5.10</version>
        </dependency>
        <dependency>
            <groupId>commons-net</groupId>
            <artifactId>commons-net</artifactId>
            <version>3.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.jcraft</groupId>
            <artifactId>jsch</artifactId>
            <version>0.1.55</version>
        </dependency>
        <dependency>
            <groupId>com.sun.mail</groupId>
            <artifactId>jakarta.mail</artifactId>
            <version>2.0.1</version>
        </dependency>
        <dependency>
            <groupId>jakarta.servlet</groupId>
            <artifactId>jakarta.servlet-api</artifactId>
            <version>6.0.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>2.0.16</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-simple</artifactId>
            <version>2.0.16</version>
        </dependency>
    </dependencies>

    <build>
        <finalName>reportplanner</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>jakarta.servlet</groupId>
                            <artifactId>jakarta.servlet-api</artifactId>
                        </exclude>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                        <exclude>
                            <groupId>org.springframework.boot</groupId>
                            <artifactId>spring-boot-starter-tomcat</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

This is the main class:

@Slf4j
@SpringBootApplication
public class ReportPlannerApplication extends SpringBootServletInitializer {

    public static void main(String[] args) {
        log.info("Starting Report Planner Application");
        SpringApplication.run(applicationClass, args);
    }

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(applicationClass);
    }

    private static final Class<ReportPlannerApplication> applicationClass = ReportPlannerApplication.class;
}

However, when I try to run the application from my IDE (e.g., IntelliJ IDEA, Eclipse), I encounter the following error:

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

Description:

Web application could not be started as there was no org.springframework.boot.web.servlet.server.ServletWebServerFactory bean defined in the context.

I understand this happens because I excluded Tomcat from the dependency:

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

My goal is to use Tomcat as an embedded server only when running the application locally from the IDE (e.g., using mvn spring-boot:run) but exclude it from the final WAR to avoid conflicts with WildFly.

Is there a way to configure the project so that:

• Tomcat is included only during local runtime (e.g., from the IDE).
• Tomcat is excluded from the WAR when building the application for WildFly deployment?

Answer 1

1. Maven-based solution

You can solve this issue with maven profiles. Let's define local profile for your local run and prod for production environment with WildFly:

<profiles>
    <profile>
        <id>local</id>
        <activation>
            <activeByDefault>true</activeByDefault>
        </activation>
        <properties>
            <tomcat-scope>compile</tomcat-scope>
        </properties>
    </profile>
    <profile>
        <id>prod</id>
        <activation>
            <activeByDefault>false</activeByDefault>
        </activation>
        <properties>
            <tomcat-scope>test</tomcat-scope>
        </properties>
    </profile>
</profiles>

Now instead of excluding spring-boot-starter-tomcat you need to specify it as a dependency referencing profile-dependent scope:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    <scope>${tomcat-scope}</scope>
</dependency>

Finally, when you run your Spring Boot application locally you need to extend the command as

mvn spring-boot:run -P local

This would apply maven profile local to your config replacing ${tomcat-scope} with compile.

If this doesn't work out you could move spring-boot-starter-tomcat into <dependencies> section of local profile:

<profiles>
    <profile>
        <id>local</id>
        <activation>
            <activeByDefault>true</activeByDefault>
        </activation>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-tomcat</artifactId>
            </dependency>
        </dependencies>
    </profile>
    <profile>
        <id>prod</id>
        <activation>
            <activeByDefault>false</activeByDefault>
        </activation>
    </profile>
</profiles>

2. Spring Boot -based solution

The same can be achieved by exclusion of Tomcat-related autoconfiguration via application config file. Let's create application-prod.yml and specify this:

spring:
  autoconfigure:
    exclude: org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryAutoConfiguration

Now when you run your application with profile prod Tomcat is off.