1.什么是Spring Shell？

Spring Shell是Spring生态中的一员，用于开发命令行应用程序，官网：https://projects.spring.io/spring-shell/ 。 Spring Shell构建在JLine之上，集成Bean Validation API实现命令参数校验。从2.0版本开始，Spring Shell还可以非常方便地与Spring Boot进行集成，直接使用Spring Boot提供的一些非常实用的功能（如：打包可执行jar文件）。

2.代码工程

实验目的：测试各种Spring shell功能

pom.xml

<?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">    <parent>        <artifactId>springboot-demo</artifactId>        <groupId>com.et</groupId>        <version>1.0-SNAPSHOT</version>    </parent>    <modelVersion>4.0.0</modelVersion>
    <artifactId>Spring-Shell</artifactId>
    <properties>        <maven.compiler.source>8</maven.compiler.source>        <maven.compiler.target>8</maven.compiler.target>    </properties>    <dependencies>
        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-web</artifactId>        </dependency>
        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-autoconfigure</artifactId>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-test</artifactId>            <scope>test</scope>        </dependency>        <dependency>            <groupId>org.springframework.shell</groupId>            <artifactId>spring-shell-starter</artifactId>            <version>2.0.0.RELEASE</version>        </dependency>    </dependencies>    <build>        <plugins>            <plugin>                <groupId>org.springframework.boot</groupId>                <artifactId>spring-boot-maven-plugin</artifactId>            </plugin>        </plugins>    </build></project>

command

第一个hello word例子

package com.et.spring.shell.command;
import org.springframework.shell.standard.ShellCommandGroup;import org.springframework.shell.standard.ShellComponent;import org.springframework.shell.standard.ShellMethod;import org.springframework.shell.standard.ShellOption;
import javax.validation.constraints.Size;import java.util.List;
@ShellComponent@ShellCommandGroup("HelloWorld")public class HelloWorld {
    @ShellMethod("Say hello")    public void hello(@ShellOption(defaultValue = "World")String name) {        System.out.println("hello, " + name + "!");    }
}

各种常见参数设置

package com.et.spring.shell.command;
import org.springframework.shell.standard.ShellCommandGroup;import org.springframework.shell.standard.ShellComponent;import org.springframework.shell.standard.ShellMethod;import org.springframework.shell.standard.ShellOption;
import javax.validation.constraints.Size;import java.util.List;
@ShellComponent@ShellCommandGroup("Calculator")public class Calculator {    // give multi name    //@ShellMethod for group    //@ShellMethod(value = "Add numbers.", key = {"sum", "addition"})    @ShellMethod(value = "Add numbers.",  key = {"sum", "addition"}, prefix = "-", group = "Cal")    public void add(int a, int b) {        int sum = a + b;        System.out.println(String.format("%d + %d = %d", a, b, sum));    }
    @ShellMethod("Echo command help")    public void myhelp(@ShellOption({"-C", "--command"}) String cmd) {        System.out.println(cmd);    }
    // params is collection    @ShellMethod("Add by list")    public void addByList(@ShellOption(arity = 3) List<Integer> numbers) {        int s = 0;        for(int number : numbers) {            s += number;        }        System.out.println(String.format("s=%d", s));    }    @ShellMethod("Echo.")    public void echo(String what) {        System.out.println(what);    }    // use @Size validate param length    @ShellMethod("Change password")    public void changePwd(@Size(min = 6, max = 30) String pwd) {        System.out.println(pwd);    }}

控制命令的执行顺序

package com.et.spring.shell.command;
import org.springframework.shell.Availability;import org.springframework.shell.standard.ShellCommandGroup;import org.springframework.shell.standard.ShellComponent;import org.springframework.shell.standard.ShellMethod;
@ShellComponent@ShellCommandGroup("Downloader")public class Downloader {    private boolean connected = false;
    @ShellMethod("Connect server")    public void connect() {        connected = true;    }
    @ShellMethod("Download file")    public void download() {        System.out.println("Downloaded.");    }
    // download availability    public Availability downloadAvailability() {        return connected ? Availability.available():Availability.unavailable("you are not connected");    }}

DemoApplication.java

package com.et.spring.shell;
import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplicationpublic class DemoApplication {
   public static void main(String[] args) {      SpringApplication.run(DemoApplication.class, args);   }}

以上只是一些关键代码，所有代码请参见下面代码仓库

代码仓库

https://github.com/Harries/springboot-demo

3.测试

打包Spring Boot应用

mvn clean package -Dmaven.test.skip=true

启动程序

java -jar Spring-Shell-1.0-SNAPSHOT.jar

执行命令, 输入help，查看所有命令

执行命令

shell:>sum 1 21 + 2 = 3

4.引用

https://docs.spring.io/spring-shell/reference/getting-started.html
https://www.cnblogs.com/nuccch/p/11067342.html
http://www.liuhaihua.cn/archives/710583.html

ITPub博客

Spring Boot集成Spring Shell快速入门Demo