SpringBoot打war包步骤：

1.修改pom文件将package格式修改成war

  <packaging>war</packaging>

2、将pom.xml文件添加build需要

 <!--没有主清单属性-->
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <mainClass>com.leeue.App</mainClass>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>

            </plugin>


            <!--        war包需要-->
            <plugin>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.6</version>
                <configuration>
                    <!--如果想在没有web.xml文件的情况下构建WAR，请设置为false。-->
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>


        </plugins>


    </build>

3、最重要。将App.java里面修改继承 SpringBootServletInitializer并重写configure方法

public class App extends SpringBootServletInitializer {

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

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return builder.sources(App.class);
    }
}