1、首先在pom里添加主类：

<plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-assembly-plugin</artifactId>
        <version>3.0.0</version>
        <configuration>
          <appendAssemblyId>false</appendAssemblyId>
          <descriptors>
            <descriptor>conf/assembly.xml</descriptor>
          </descriptors>
        </configuration>
          <executions>
            <execution>
              <id>assemble-all</id>
              <phase>package</phase>
              <goals>
                <goal>single</goal>
              </goals>
            </execution>
          </executions>
      </plugin>

2、使用mvn命令

接下来使用命令进行打包：

mvn clean package