Hey, what about an auto-complete interactive shell, help, and more? And without troubles, and even on the JVM?
Postman became a headache at work for me. Although in words we are all TDDs and through the red light of Cucumber we see what exactly broke, but in practice I had to send REST requests in the Postman interface much more often. At the beginning of the work, it was necessary to obtain an authentication token (a request for creation and a request for validation, the users are different), and then jump to bookmarks, edit the parameters and start other requests. Click-click-click. In a different order. I already wrote scripts with cURL, and I made out requests in IDEA - it’s not convenient. An ideal motivator for switching to automatic tests, these were just requests for understanding what was happening at some unique moment in the combination of the state of the service, its version, mainframes behind it, the weather in the house, and certainly did not fall under regression testing. Click-click-click began to eat too much time and increased the mileage of the mouse.
Spring Shell, shell , Spring. , . , — . — shell, . , — Spring State Machine. , — , — , , Kotlin, Akka "" . State Machine , .
Spring Initializr Gradle Kotlin. .
curl 'https://start.spring.io/starter.zip?type=gradle-project&language=kotlin&bootVersion=2.2.6.RELEASE&baseDir=shell-state&groupId=me.votez.spring&artifactId=shell-state&name=shell-state&description=Demo%20project%20for%20Spring%20State%20Machine%20and%20Shell&packageName=me.votez.spring.shellstate&packaging=jar&javaVersion=1.8' --compressed --output shellstate.zip && unzip shellstate.zip
Spring Shell gradle
implementation("org.springframework.shell:spring-shell-starter:2.0.0.RELEASE")
(shell). , ShellComponent ( ) , ShellMethod , . , ShellOption. , Bean Validation. , Enum ( , help).
— . — , , actuator .…
( runBlocking — )
package me.votez.spring.shellstate
import org.springframework.shell.standard.ShellComponent
import org.springframework.shell.standard.ShellMethod
import org.springframework.shell.standard.ShellOption
import kotlinx.coroutines.*
import org.springframework.shell.standard.ShellMethodAvailability
import java.util.*
import kotlin.random.Random
@ShellComponent
class ServerCommands {
private var token: String? = null
@ShellMethod("Authenticate and obtain token")
fun login(
@ShellOption name:String,
@ShellOption password:String,
@ShellOption(defaultValue = "admin") scope: String) = runBlocking {
token = UUID.randomUUID().toString()
delay(2_000)
"Connected"
}
}
@ShellMethod("List projects regstered on server")
fun list(
@ShellOption(defaultValue = "PROJECT", help = "Possible values are PROJECT and USER") type:EntityType) = when(type) {
EntityType.PROJECT -> listOf("Roga i Kopita", "Svetliy Put", "NIICHAVO")
EntityType.USER -> listOf( "Ivanov", "Petrov", "Sidorov")
}
}
enum class EntityType {
PROJECT,
USER
}
. IntelliJ IDEA, Spring Shell JLine, Linux, MacOS Windows, IDE — .
$ bash ./gradlew build
$ java -jar build/libs/shell-state-0.0.1-SNAPSHOT.jar
help, . clear, exit, quit, script, stacktrace.
2020-05-03 12:49:35.442 INFO 23211 --- [ main] m.v.s.s.ShellStateApplicationKt : Started ShellStateApplicationKt in 1.036 seconds (JVM running for 0.936)
shell:>help
AVAILABLE COMMANDS
Built-In Commands
clear: Clear the shell screen.
exit, quit: Exit the shell.
help: Display help about available commands.
script: Read and execute commands from a file.
stacktrace: Display the full stacktrace of the last error.
Server Commands
list: List projects registered on server
login: Authenticate and obtain token
shell:>help list
NAME
list - List projects registered on server
SYNOPSYS
list [[--type] entity-type]
OPTIONS
--type entity-type
Possible values are PROJECT and USER
[Optional, default = PROJECT]
. login list L, . l TAB , o TAB, login. . , > login root 123456 , — Connected. list .
list , list . :
@ShellMethodAvailability("list")
fun listAvailable() = if (token != null) Availability.available() else Availability.unavailable("cannot run without auth token")
shell, , . help , .
2020-05-02 13:30:12.593 INFO 4443 --- [ main] m.v.s.s.ShellStateApplicationKt : Started ShellStateApplicationKt in 1.525 seconds (JVM running for 1.252)
shell:>list
Command 'list' exists but is not currently available because cannot run without auth token
Details of the error have been omitted. You can use the stacktrace command to print the full stacktrace.
shell:>help
AVAILABLE COMMANDS
Built-In Commands
clear: Clear the shell screen.
exit, quit: Exit the shell.
help: Display help about available commands.
script: Read and execute commands from a file.
stacktrace: Display the full stacktrace of the last error.
Server Commands
* list: List projects regstered on server
login: Authenticate and obtain token
Commands marked with (*) are currently unavailable.
Type `help <command>` to learn more.
shell:>help list
NAME
list - List projects registered on server
SYNOPSYS
list [[--type] entity-type]
OPTIONS
--type entity-type
Possible values are PROJECT and USER
[Optional, default = PROJECT]
CURRENTLY UNAVAILABLE
This command is currently not available because cannot run without auth token.
, . , , , . command prompt, . , application.properties — , Spring Framework ( ). prompt , .
PrompProvider, , JLine.
@ConfigurationProperties(prefix="shell")
class ServerCommands : PromptProvider
lateinit var env: String
override fun getPrompt(): AttributedString =
AttributedString("${env}:>",
AttributedStyle.DEFAULT.foreground(
if (token == null) AttributedStyle.YELLOW else AttributedStyle.GREEN))
, . .
, , (soap, protobuf ) — , - . , .
Spring State Machine
, . . , , , . , … , .
Spring State Machine.
, (), -. — The Evolution of Trust. , () . xml — , - .
, . , "" . Spring State Machine , , .
, . , . — Spring SM , . " ", - , - , , — .
, , . - — , .
?
, .
, "" . . ( ) , Thread Pool, shell, SSM - — .
command prompt " ", .
, . Quick Start.
,
.
override fun configure(transitions: StateMachineTransitionConfigurer<State, Event>) {
transitions
.withExternal()
.source(State.INIT).target(State.CONNECTING)
.event(Event.LOGIN)
.and()
.withExternal()
.source(State.CONNECTING).target(State.READY).event(Event.CONNECTED)
.action { context -> context.extendedState.variables["token"] = context.messageHeaders["token"] }.and()
.withExternal()
.source(State.CONNECTING).target(State.INIT).event(Event.FAILED).and()
.withInternal()
.source(State.READY).event(Event.COMMAND).and()
.withExternal()
.source(State.READY).target(State.CONNECTING).event(Event.LOGIN)
}
....
enum class State { INIT, CONNECTING, READY }
enum class Event { LOGIN, CONNECTED, FAILED, COMMAND }
— , — . Spring. , , . .
. login:
@Autowired
lateinit var stateMachine: StateMachine<State, Event>
lateinit var token: String
@ShellMethod("Authenticate and obtain token")
fun login(
@ShellOption name: String,
@ShellOption password: String,
@ShellOption(defaultValue = "admin") scope: String) =
runBlocking {
stateMachine.sendEvent(
MessageBuilder.createMessage(Event.LOGIN, MessageHeaders(mapOf("login" to name))))
delay(1_000)
token = UUID.randomUUID().toString()
stateMachine.sendEvent(
MessageBuilder.createMessage(Event.CONNECTED, MessageHeaders(mapOf("token" to token))))
"Connected"
}
...
command prompt:
private val colors = mapOf(State.READY to AttributedStyle.DEFAULT.foreground(AttributedStyle.GREEN))
.withDefault { AttributedStyle.DEFAULT.foreground(AttributedStyle.YELLOW) }
override fun getPrompt(): AttributedString =
AttributedString("${env}:>", colors.getValue(stateMachine.state.id))
:
@ShellMethodAvailability("list")
fun listAvailable() =
if (stateMachine.state.id == State.READY) Availability.available()
else Availability.unavailable("requires authentication performed first")
Spring State Machine — (guards), , , , , .
Spring Shell is an excellent solution for specific utilities for project development, when there is a need for partial automation of non-trivial tasks.
Spring State Machine is another of many community projects that deserves more attention and is an up-to-date technology, despite prejudice.
Sample code is available on GitHub .
