一、什么是Spring Shell
?
Spring Shell
允许人们轻松创建这样的可运行应用程序,用户将在其中输入文本命令,这些命令将被执行直到程序终止。Spring Shell
项目提供了创建此类REPL
(读取,评估,打印循环)的基础结构,从而使开发人员可以使用熟悉的Spring
编程模型来专注于命令实现。
诸如解析,TAB
完成,输出着色,精美的ascii-art
表显示,输入转换和验证之类的高级功能都是免费提供的,而开发人员仅需专注于核心命令逻辑即可。
二、使用Spring Shell
2.1. 引入依赖
<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.0.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.mly.shell</groupId>
<artifactId>mly-shell</artifactId>
<version>1.0.0</version>
<name>mly-shell</name>
<description>自定义的Spring Shell</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<!-- Spring Shell 依赖 -->
<dependency>
<groupId>org.springframework.shell</groupId>
<artifactId>spring-shell-starter</artifactId>
<version>2.0.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2.2. 第一个小例子
import org.springframework.shell.standard.ShellComponent;
import org.springframework.shell.standard.ShellMethod;
/**
* @author 墨龙吟
* @version 1.0.0
* @ClassName CommandsOne.java
* @Email [email protected]
* @Description 第一条命令
* @createTime 2019年10月31日 - 13:22
*/
@ShellComponent
public class CommandsOne {
@ShellMethod("Add two integers together.")
public int add (int a, int b) {
return a + b;
}
}
运行输出:(输入exit
退出命令行)
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.2.0.RELEASE)
shell:>add 1 3
4
shell:>exit
Process finished with exit code 0
构建jar
包运行
E:\owner_app\mly-shell>mvn install -DskipTests
[INFO] Scanning for projects...
[INFO]
[INFO] ----------------------< com.mly.shell:mly-shell >-----------------------
[INFO] Building mly-shell 1.0.0
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-resources-plugin:3.1.0:resources (default-resources) @ mly-shell ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ mly-shell ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 2 source files to E:\owner_app\mly-shell\target\classes
[INFO]
[INFO] --- maven-resources-plugin:3.1.0:testResources (default-testResources) @ mly-shell ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory E:\owner_app\mly-shell\src\test\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.8.1:testCompile (default-testCompile) @ mly-shell ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to E:\owner_app\mly-shell\target\test-classes
[INFO]
[INFO] --- maven-surefire-plugin:2.22.2:test (default-test) @ mly-shell ---
[INFO] Tests are skipped.
[INFO]
[INFO] --- maven-jar-plugin:3.1.2:jar (default-jar) @ mly-shell ---
[INFO] Building jar: E:\owner_app\mly-shell\target\mly-shell-1.0.0.jar
[INFO]
[INFO] --- spring-boot-maven-plugin:2.2.0.RELEASE:repackage (repackage) @ mly-shell ---
[INFO] Replacing main artifact with repackaged archive
[INFO]
[INFO] --- maven-install-plugin:2.5.2:install (default-install) @ mly-shell ---
[INFO] Installing E:\owner_app\mly-shell\target\mly-shell-1.0.0.jar to D:\DevelopSoftware\apache-maven-3.6.1\repository\com\mly\shell\mly-shell\1.0.0\mly-shell-1.0.0.jar
[INFO] Installing E:\owner_app\mly-shell\pom.xml to D:\DevelopSoftware\apache-maven-3.6.1\repository\com\mly\shell\mly-shell\1.0.0\mly-shell-1.0.0.pom
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 5.268 s
[INFO] Finished at: 2019-10-31T13:35:11+08:00
[INFO] ------------------------------------------------------------------------
E:\owner_app\mly-shell>cd target
E:\owner_app\mly-shell>java -jar mly-shell-1.0.0.jar # 执行命令
2.3. 自定义命令名称的方法
2.3.1. 默认为方法名为命令名:
@ShellMethod("Add two integers together.")
public int add (int a, int b) {
return a + b;
}
// shell:>add 1 3 #返回结果 4
这样子上面的命令名:add 1 2
, 将会返回3
2.3.2 如果方法名是由驼峰单词组成,命令名将会变以横杠分割多个单词:
@ShellMethod(value = "add sum")
public int sumAdd(int a, int b) {
return a + b;
}
// shell:>sum-add 1 2 #返回结果 3
2.3.3. 如果是命令是以下划线分割的,将还以原型式作为命令名
@ShellMethod(value = "add sumasas")
public int sum_add(int a, int b) {
return a + b;
}
// shell:>sum_adds 1 3 # 返回结果 4
2.3.4 命令也可以有别名
@ShellMethod(value = "add sumasas", key = {"sum0", "sum1", "sum2"})
public int adds(int a, int b) {
return a + b;
}
// shell:>sum0 1 4 # 返回结果 5
// shell:>sum1 1 3 # 返回结果 4
// shell:>sum2 1 3 # 返回结果 4
2.4. 参数的使用
命令参数使用方法:
@ShellMethod("Display stuff")
public String echo (int a, int b, int c) {
return String.format("You said a = %d, b = %d, c = %d", a, b, c);
}
参数使用:
shell:>echo 1 2 3 # 使用位置参数
You said a = 1, b = 2, c = 3
shell:>echo --a 1 --b 2 --c 3 # 完整的按名称参数
You said a = 1, b = 2, c = 3
shell:>echo --b 2 --c 3 --c 1 # 也可以需要重新排列名称参数
You said a = 1, b = 2, c = 3
shell:>echo --a 1 2 3 # 也可以混合使用
You said a = 1, b = 2, c = 3
shell:>echo 1 --c 3 2 # 非名称参数按他们出现顺序解析
You said a = 1, b = 2, c = 3
2.5. 自定义参数键
@ShellMethod(value = "Display stuff", prefix = "-")
public String echo (int a, int b, @ShellOption("--third") int c) {
return String.format("You said a = %d, b = %d, c = %d", a, b, c);
}
参数使用:
shell:>echo -a 1 -b 2 --third 3
You said a = 1, b = 2, c = 3
shell:>echo 1 2 3
You said a = 1, b = 2, c = 3
shell:>echo 1 2 --third 3
You said a = 1, b = 2, c = 3
2.6. 可选参数和默认参数
@ShellMethod("两数相加:")
public int add (@ShellOption(defaultValue = "3") int a, int b) {
return a + b;
}
参数使用
shell:>add 3 # 这样使用是不对的哦!
Parameter '--b int' should be specified
Details of the error have been omitted. You can use the stacktrace command to print the full stacktrace.
shell:>add --b 3 # 默认 a 参数, 需要指定参数 b
6
shell:>add 1 2 # 正常的使用
3
2.7. 多个参数可以使用Arity
上面情况每个参数都映射到用户输入单个参数,当对应多个参数时需要用到Arity
对应一个数组或者是一个集合来承接参数。
@ShellMethod("多个数字相加:")
public float add1 (@ShellOption(arity = 3) float[] numbers) {
return numbers[0] + numbers[1] + numbers[2];
}
// ====================输出=======================
shell:>add1 2 3.5 6.7
12.2
2.8 对于布尔参数的特殊处理
当涉及参数Arity
时,默认情况下,有一种参数会接受特殊处理:布尔值(即boolean
和java.lang.Boolean
)参数的行为类似于默认情况下的arity()
of 0
,允许用户使用“标志”方法设置其值。
参数使用展示:
@ShellMethod("Terminate the system.")
public String shutdown(boolean force) {
return "You said " + force;
}
// ====================错误输出=======================
shell:>shutdown true
Too many arguments: the following could not be mapped to parameters: 'true'
Details of the error have been omitted. You can use the stacktrace command to print the full stacktrace.
// ====================正确输出=======================
shell:>shutdown
You said false
shell:>shutdown --force
You said true
以上得出结论:布尔参数默认为false
。
2.9. 多字符串操作:
Spring Shell
接受用户输入并将其用 单词 标记化,并按空格分隔。如果用户想提供一个包含空格的参数值,则该值必须用引号引起来。单引号('
)和双"
引号()都受支持,并且这些引号将不属于值的一部分。
@ShellMethod("接受多个值:")
public String echo(String what) {
return "You said " + what;
}
// ====================正确输出=======================
shell:>echo "Java python"
You said Java python
shell:>echo 'java Python'
You said java Python
shell:>echo "I'm tom"
You said I'm tom
2.10. 参数验证
Spring Shell
与Bean Validation API
集成在一起,以支持对命令参数的验证。
@ShellMethod("修改密码:")
public String changePassword(@Size(min = 8, max = 16, message = "密码长度必须在8到16之间") String password) {
return "密码修改成功:" + password;
}
// ====================正确输出=======================
shell:>change-password 12345
The following constraints were not met:
--password string : 密码长度必须在8到16之间 (You passed '12345')
shell:>change-password 1234567889
密码修改成功:1234567889
2.11. 内置命令
shell:>help
AVAILABLE COMMANDS
Built-In Commands
clear: 清除屏幕.
exit, quit: 退出shell.
help: 显示有关可用命令的帮助.
history: 显示以前的命令
script: 读和执行命令从一个文件.
stacktrace: 显示上一个错误的完整堆栈跟踪.
wxz
Commands One
connect: Connect to the server.
download: Download the nuclear codes.
2.12. 命令分组
-
方法一:在
ShellMethod
中添加group
@ShellComponent(value = "自定义的命令") public class UserCommands { @ShellMethod(value = "命令一", group = "分组一") public void command1() {} @ShellMethod(value = "命令二", group = "分组二") public void command2() {} @ShellMethod(value = "命令三", group = "分组三") public void command3() {} }
当输入
help
命令时显示:shell:>help AVAILABLE COMMANDS Built-In Commands clear: Clear the shell screen. exit, quit: Exit the shell. help: Display help about available commands. history: Display or save the history of previously run commands script: Read and execute commands from a file. stacktrace: Display the full stacktrace of the last error. 分组一 command1: 命令一 分组三 command3: 命令三 分组二 command2: 命令二
-
使用
ShellCommandGroup
注解@ShellComponent(value = "自定义的命令") @ShellCommandGroup(value = "分组666") public class UserCommands { @ShellMethod(value = "命令一") public void command1() {} @ShellMethod(value = "命令二") public void command2() {} @ShellMethod(value = "命令三") public void command3() {} }
当输入
help
命令时显示:shell:>help AVAILABLE COMMANDS Built-In Commands clear: Clear the shell screen. exit, quit: Exit the shell. help: Display help about available commands. history: Display or save the history of previously run commands script: Read and execute commands from a file. stacktrace: Display the full stacktrace of the last error. 分组666 command1: 命令一 command2: 命令二 command3: 命令三 shell:>
2.13. 覆盖和禁止内置命令
禁止所有内置命令:在依赖中剔除
<dependency>
<groupId>org.springframework.shell</groupId>
<artifactId>spring-shell-starter</artifactId>
<version>2.0.1.RELEASE</version>
<exclusions>
<exclusion>
<groupId>org.springframework.shell</groupId>
<artifactId>spring-shell-standard-commands</artifactId>
</exclusion>
</exclusion>
</dependency>
禁止某一个特定命令:例如禁止help
命令
public static void main(String[] args) throws Exception {
String[] disabledCommands = {"--spring.shell.command.help.enabled=false"};
String[] fullArgs = StringUtils.concatenateStringArrays(args, disabledCommands);
SpringApplication.run(MyApp.class, fullArgs);
}
覆盖内置命令:
public class MyClear implements Clear.Command {
@ShellMethod("Clear the screen, only better.")
public void clear() {
// ...
}
}
2.14. 自定义命令提示,默认的是shell:>
@Component
public class MyCommandShell implements PromptProvider {
@Override
public AttributedString getPrompt() {
return new AttributedString("long : >",
AttributedStyle.DEFAULT.foreground(AttributedStyle.RED));
}
}
这样将会把shell:>
替换为long:>
。