一、springboot+maven工程——打war包步骤如下:
1.修改父pom.xml文件:
<packaging>pom</packaging>
<!-- 方式一 Begin -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
   <!-- 移除嵌入式tomcat插件 -->
    <exclusions>
        <exclusion>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>org.apache.tomcat</groupId>
    <artifactId>tomcat-servlet-api</artifactId>
    <version>7.0.92</version>
    <scope>provided</scope>
</dependency>
<!-- 方式一 End -->
<!-- 方式二 Begin -->
<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>
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.1.0</version>
    <scope>provided</scope>
</dependency> 
<!-- 方式二 End -->
             
<!-- 方式三 Begin -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    <scope>provided</scope>
</dependency>
<!-- 方式三 End -->
注:在这里将scope属性设置为provided,这样在最终形成的WAR中不会包含这个JAR包,因为Tomcat或Jetty等服务器在运行时将 会提供相关的API类。
2.修改web模块的pom.xml文件:
<packaging>war</packaging>
3.修改启动类方法:
方式一:继承 SpringBootServletInitializer 重写 configure()
@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}
// 修改如下
@SpringBootApplication
public class Application extends SpringBootServletInitializer {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return builder.sources(Application.class);
    }
}
方式二:创建一个新的类继承 SpringBootServletInitializer 重写 configure()
public class ServletInitializer extends SpringBootServletInitializer {
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(Application.class);
    }
}
总结:父pom.xml文件的packaging为pom方式,有主方法的模块pom.xml文件的packaging为war方式,其他模块pom.xml的packaging为jar方式。
4.打包:
进入到工程文件夹下,执行 mvn clean package 命令。
原文:https://www.cnblogs.com/zhyp/p/14034653.html