Use the clIKT framework to build a scalable Java class library application
Use the clIKT framework to build a scalable Java class library application
Overview:
Clikt is a lightweight command line parsing library written by Kotlin, which can help us easily build scalable Java library applications.In this article, we will introduce how to use the CLIKT framework to create an application -based application and achieve scalability.
Environmental construction:
Before starting, make sure that Java and Kotlin have been installed in your environment.Then, the CLIKT library is introduced by adding the following dependencies in the Gradle file of the project:
groovy
implementation 'com.github.ajalt.clikt:clikt:3.2.0'
Write code:
We will create a simple example application that provides some basic command line operations, such as adding users and deleting users.First, we need to create a main command class that inherits from the `Cliktcommand` class.
kotlin
import com.github.ajalt.clikt.core.CliktCommand
class MyApp : CliktCommand() {
override fun run() {
// Here you can process the main command logic
}
}
fun main(args: Array<String>) = MyApp().main(args)
In the `Run` function, you can process the main command logic.For example, you can show users some prompt information or call other commands.
Next, we need to create some sub -commands.The sub -commands can expand the `Cliktcommand` class and cover the` run` function.The following is an example of a sub -command to add a user.
kotlin
import com.github.ajalt.clikt.core.CliktCommand
import com.github.ajalt.clikt.parameters.arguments.argument
import com.github.ajalt.clikt.parameters.options.option
class AddUserCommand : CliktCommand(help = "Add a new user") {
private val username by argument(help = "Username")
private val password by option(help = "Password").prompt(hideInput = true)
override fun run() {
// Here you can add user logic
}
}
In this example, we use the `argument` function to define a necessary parameter` username`, and use the `Option` function to define an optional option` password`.The `prompt` function can be entered in the command line without display.
Finally, we need to register the sub -command in the main command.In the `Run` function of the` MyApp` class, use the `registerSubcommand` function registry command.
kotlin
class MyApp : CliktCommand() {
override fun run() {
// Register command
registerSubcommand(AddUserCommand())
registerSubcommand(DeleteUserCommand())
// Here you can process the main command logic
}
}
In the above example, we registered the two sub -commands of the two sub -commands of `addusercommand` and` deleteusersercommand`.
Compilation and operation:
After completing the writing code, we can use the following command to compile and run the application:
shell
kotlinc *.kt -include-runtime -d app.jar
java -jar app.jar [command] [options] [arguments]
Replace `app.jar` as your output file name, [Command] [options] [arguments]` `the command line parameters defined for you.
Summarize:
This article introduces the process of building scalable Java library applications using the CLIKT framework.Using Clikt, we can easily create command line applications and achieve scalability.In actual development, you can add more sub -commands and parameters based on this example application to meet your specific needs.I hope this article will help you start using CLIKT for development.
