Packaging as JAR

1. Pay attention to two key points: you must either comment out <skip>true</skip> or change its value to false. Otherwise, you will encounter a "no main manifest attribute" error upon startup. Additionally, update the <mainClass> tag with the fully qualified name of your application's entry point.

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <version>${spring.boot.version}</version>
    <configuration>
        <mainClass>com.mycompany.app.ApplicationLauncher</mainClass>
        <!-- Ensure skip is commented out or set to false -->
    </configuration>
    <executions>
        <execution>
            <id>executable-jar-packaging</id>
            <goals>
                <goal>repackage</goal>
            </goals>
        </execution>
    </executions>
</plugin>

2. Running clean followed by package will generate the artifact shown in the image below.

3. Open your-app.jar/META-INF/MANIFEST.MF to inspect the complete manifest details.

4. Verify the execution on Windows by running: java -jar your-app.jar

Packaging as WAR

1. Declare WAR packaging in the pom.xml

<packaging>war</packaging> <!-- Place this outside the <properties> block -->

2. Exclude the embeddded Tomcat and use an external Tomcat dependency

Add the Servlet API dependency and exclude the Tomcat starter from the web dependency.

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>4.0.1</version>
    <scope>provided</scope>
</dependency>
<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>

3. Extend SpringBootServletInitializer in your main class

This provides a launcher for the Spring Boot project when deployed to a Servlet container (its purpose is to initialize the internal Servlet components).

4. Override the configure() method in the main class

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

    @Override // Specifies the entry point for the Servlet container initialization
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return builder.sources(WebApplication.class);
    }
}

5. Execute the Maven package phase

You might encounter a packaging error.

Method 1: Add a configuration property to skip the check for web.xml.

<properties>
    <failOnMissingWebXml>false</failOnMissingWebXml>
</properties>

Method 2: Upgrade the Maven War Plugin version to 3.0.0 or higher.