From: https://blog.csdn.net/q15858187033/article/details/80742117

SpringBoot官方提供的demo中，pom.xml文件里引用了官方提供的打包插件

    <build>
        <plugin>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
     </build>

        通过这种方式打包出来的项目，所有文件都放在一个jar包中。这使得jar包非常臃肿，不利于服务器上部署。这时候就希望在maven打包的时候，把一些结构分离出jar包外。

        例如一个项目的目录结构是这样的：，最终想打包变成这种结构。其中resources下的配置文件放在config目录下，所有的依赖包放在lib下，程序的启动jar就会变得很小。并且代码改变之后，只需要将打包出来的jar上传到服务器替换后再运行就可以了。

        要自定义打包的结构，需要修改pom.xml文件中<build>标签里的内容

    <build>
            <finalName>FlightChangeService</finalName>
            <resources>
                <resource>
                    <!--指定mapping下的所有xml文件打包在jar中-->
                    <targetPath>${project.build.directory}/classes</targetPath>
                    <directory>src/main/resources</directory>
                    <filtering>true</filtering>
                    <includes>
                        <include>mapping/*.xml</include>
                    </includes>
                </resource>
                <resource>
                    <!--resources下一级的所有.xml .properties文件复制到config目录下-->
                    <targetPath>${project.build.directory}/config</targetPath>
                    <directory>src/main/resources</directory>
                    <filtering>true</filtering>
                    <includes>
                        <include>**.xml</include>
                        <include>**.properties</include>
                    </includes>
                </resource>
            </resources>
            <plugins>
                <!--maven-dependency插件，将项目所有依赖包放到lib目录下-->
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-dependency-plugin</artifactId>
                    <executions>
                        <execution>
                            <id>copy-dependencies</id>
                            <phase>package</phase>
                            <goals>
                                <goal>copy-dependencies</goal>
                            </goals>
                            <configuration>
                                <type>jar</type>
                                <includeTypes>jar</includeTypes>
                                <outputDirectory>
                                    ${project.build.directory}/lib
                                </outputDirectory>
                            </configuration>
                        </execution>
                    </executions>
                </plugin>
     
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-jar-plugin</artifactId>
                    <configuration>
                        <classesDirectory>target/classes/</classesDirectory>
                        <archive>
                            <!--生成的jar中，不要包含pom.xml和pom.properties这两个文件-->
                            <addMavenDescriptor>false</addMavenDescriptor>
                            <manifest>
                                <mainClass>com.loongair.Application</mainClass>
                                <!-- 打包时 MANIFEST.MF文件不记录的时间戳版本 -->
                                <useUniqueVersions>false</useUniqueVersions>
                                <addClasspath>true</addClasspath>
                                <classpathPrefix>lib/</classpathPrefix>
                            </manifest>
                            <manifestEntries>
                                <!--jar中的MANIFEST.MF文件ClassPath需要添加config目录才能读取到配置文件-->
                                <Class-Path>config/ .</Class-Path>
                            </manifestEntries>
                        </archive>
                    </configuration>
                </plugin>
            </plugins>
        </build>

        执行maven install之后target目录下就生成了我们自定义的包结构了