pom.xml 新增一個依賴和外掛

<build>
        <finalName>${project.artifactId}</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
 

            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml
 
>
                </configuration>
            </plugin>
        </plugins>
    </build>

啟動檔案需要 繼承 SpringBootServletInitializer， 並重寫 configure

@SpringBootApplication
public class MainApplication extends SpringBootServletInitializer {

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

    @Override
 

    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return builder.sources(MainApplication.class);
    }
}

切換到專案根目錄，mvn clean package 打 war, 拷貝到 Tomcat webapps 下面 啟動 Tomcat 。