大致：想要使用Spring Shell，則專案需要是 Spring Boot專案，下面貼出結構和程式碼

1.POM依賴

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <
 
modelVersion>4.0.0</modelVersion>

  <!--如果原先是Maven專案，不是Spring Boot專案，則這個Parent依賴需要加上-->
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.1.RELEASE</version>
    <
 
relativePath/> <!-- lookup parent from repository -->
  </parent>

  <groupId>my</groupId>
  <artifactId>SpringShellDemo</artifactId>
  <version>1.0-SNAPSHOT</version>

  <name>SpringShellDemo</name>
  <!-- FIXME change it to the project's website 
 
-->
  <url>http://www.example.com</url>


  <properties>
    <java.version>1.8</java.version>
  </properties>

  <!--下面是依賴項-->
  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
      <version>2.1.1.RELEASE</version>
    </dependency>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <version>2.1.1.RELEASE</version>
      <scope>test</scope>
    </dependency>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter</artifactId>
      <version>2.1.1.RELEASE</version>
    </dependency>

    <dependency>
      <groupId>org.springframework.shell</groupId>
      <artifactId>spring-shell-starter</artifactId>
      <version>2.0.0.RELEASE</version>
    </dependency>
  </dependencies>

  <!--新增Spring BootMaven外掛-->
  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
        <version>2.0.0.RELEASE</version>
      </plugin>
    </plugins>
  </build>

</project>

2.DemoApplication.java Spring Boot啟動類

package command;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {

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

}

3.MyCommand.java 命令類

package command;

import org.springframework.shell.standard.ShellComponent;
import org.springframework.shell.standard.ShellMethod;

@ShellComponent
public class MyCommandDemo {


    @ShellMethod("Add two intergers together.")
    public int add(int a,int b){
        return a+b;
    }
}

如果IDE工具是IDEA，執行

mvn clean install -DskipTests：跳過測試，直接安裝Install

java -jar target\**.jar(安裝的jar包名稱):執行jar包

問題：如果啟動時出現未找到主程式，則需檢視主POM檔案是否新增Parent的Spring Boot依賴