How to integrate the 'Typed Command Line Parser' framework in the Java class library and expand it
How to integrate the 'Typed Command Line Parser' framework in the Java class library and expand it
introduction:
Typed Command Line Parser is a convenient, simple and flexible Java -class library framework for analysis and processing command line parameters.This article will introduce how to integrate and use the framework in the Java project, and demonstrate how to expand to meet specific needs.
Step 1: Import Typed Command Line Parser Library
First of all, to integrate the 'Typed Command Line Parser' framework in the Java project, the corresponding library needs to be added to the project's dependence.You can download the latest version of the library from the official website (https://github.com/remkop/picocli), or add it to the project through building tools such as Maven or Gradle.
Step 2: Create the command line parameter class
In the Java project that integrates the 'Typed Command Line Parser' library, we can simplify the analysis and processing of parameters by defining a class specifically used to store the classes that storage command line parameters.This class can contain various types of member variables for storing different types of parameter values.
Below is the command line parameter of an example:
import picocli.CommandLine.Option;
import picocli.CommandLine.Command;
@Command(name = "MyApp", mixinStandardHelpOptions = true, version = "1.0",
description = "Example Program")
class MyApp {
@Option(names = {"-n", "--name"}, description = "姓名")
private String name;
@Opting (names = {"-a", "--Age"}, description = "Age")
private int age;
public void run() {
System.out.println ("Name:" + Name);
System.out.println ("age:" + Age);
}
}
In this example, we use the@option` annotation to define the two command line options: `--name` and`-Age`.The values of these options will be stored in member variables of `Name` and Age`.`@Command` Annotation is used to provide basic information for the entire command line application.
Step 3: Analyze and handle command line parameters
Once the command line parameters are defined, we can use the 'Typed Command Line Parser' framework to analyze and process the command line parameters.The following is an example code that demonstrates how to analyze and handle the command line parameters:
import picocli.CommandLine;
import picocli.CommandLine.ParseResult;
public class Main {
public static void main(String[] args) {
MyApp app = new MyApp();
CommandLine commandLine = new CommandLine(app);
ParseResult parseResult = commandLine.parseArgs(args);
if (parseResult.isUsageHelpRequested()) {
commandLine.usage(System.out);
return;
} else if (parseResult.isVersionHelpRequested()) {
commandLine.printVersionHelp(System.out);
return;
}
app.run();
}
}
In this example, we first created the `MyApp` object, then created the` CommandLine` object, and passed the `MyApp` object as a parameter to it.Next, we call the `PARSEARGS` method to analyze the command line parameters.If the user requests helping or version information, print the help information or version information and exit.Otherwise, we call the `run` method to execute the application logic.
Step 4: Run the application and pass the command line parameters
After completing the above steps, we can run Java applications in the terminal and pass the command line parameters.For example, we can use the following command to pass on the name and age parameters:
java Main --name John --age 25
The running result will output:
Name: John
Age: 25
in conclusion:
This article introduces how to integrate the 'Typed Command Line Parser' framework in the Java library and expand it.By defining a command line parameter class, and using the 'Typed Command Line Parser' framework analysis and processing command line parameters, we can easily implement a powerful and flexible command line application.This framework also provides many other functions, such as parameter verification, custom help information, etc., which can further expand and customize according to project needs.
