Framework recommendations that can be used for command line processing in the Java class library
Framework recommendations that can be used for command line processing in the Java class library
Overview:
In Java development, command line processing is a common demand to resolve the command line input parameters, perform corresponding operations, and provide friendly user interface.Using appropriate frameworks can simplify the tasks of command line processing and improve development efficiency.This article will introduce some commonly used Java command line processing frameworks and provide code examples to help readers better understand their usage and advantages.
1. Apache Commons CLI：
Apache Commons Cli is a popular Java command line processing framework with flexibility and ease of use.It provides a set of classes and methods to analyze and handle command line options and parameters.Below is an example of using Apache Commons Cli:
import org.apache.commons.cli.*;
public class CommandLineExample {
public static void main(String[] args) {
Options options = new Options();
options.addOption("h", "help", false, "Display help information");
options.addOption("v", "verbose", false, "Enable verbose mode");
CommandLineParser parser = new DefaultParser();
try {
CommandLine cmd = parser.parse(options, args);
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if (cmd.hasOption("h")) {
HelpFormatter formatter = new HelpFormatter();
formatter.printHelp("myapp", options);
}
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if (cmd.hasOption("v")) {
System.out.println("Verbose mode enabled");
}
} catch (ParseException e) {
System.err.println("Failed to parse command line arguments");
e.printStackTrace();
}
}
}
In the above examples, we define two command line options: -H or-Help (for displaying help information) and -V or --Verbose (for opening detailed mode).The program performs the corresponding operation by checking the options in the command line parameters.
2. picocli：
Picocli is a lightweight command line processing framework with the characteristics of annotation drive.It has a lot of useful functions, such as automatically generating help information, type conversion, nested sub -commands, etc.The following is an example of using picocli:
import picocli.CommandLine;
import picocli.CommandLine.Command;
import picocli.CommandLine.Option;
@Command(name = "myapp", mixinStandardHelpOptions = true, version = "1.0",
description = "A simple command line application")
public class CommandLineExample {
@Option(names = {"-v", "--verbose"}, description = "Enable verbose mode")
private boolean verbose;
public static void main(String[] args) {
CommandLineExample app = new CommandLineExample();
CommandLine cmd = new CommandLine(app);
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cmd.parse(args);
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if (cmd.isUsageHelpRequested()) {
cmd.usage(System.out);
return;
}
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if (cmd.isVersionHelpRequested()) {
cmd.printVersionHelp(System.out);
return;
}
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if (app.verbose) {
System.out.println("Verbose mode enabled");
}
}
}
In the above examples, we use the Picocli annotation driver to define an command line application.Use -mixinstandardhelPoptions parameters can automatically generate help information, and define a -V or-Verbose option by @Option annotation.
3. JCOMMANDER:
JCOMMANDER is another popular command line processing framework, which has simple and easy -to -use characteristics.It defines the command line options and parameters by annotation, and provides a simple way to analyze and process the command line input.The following is an example of using JCOMMANDER:
import com.beust.jcommander.JCommander;
import com.beust.jcommander.Parameter;
public class CommandLineExample {
@Parameter(names = {"-v", "--verbose"}, description = "Enable verbose mode")
private boolean verbose = false;
public static void main(String[] args) {
CommandLineExample app = new CommandLineExample();
JCommander cmd = JCommander.newBuilder()
.addObject(app)
.build();
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cmd.parse(args);
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if (cmd.getParsedCommand() == null) {
cmd.usage();
return;
}
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if (app.verbose) {
System.out.println("Verbose mode enabled");
}
}
}
In the above examples, we use the JCOMMANDER annotation method to define an command line application.Create a JCOMMANDER instance through newBuilder (). AddObject (app) .build () method, and use the PARSE method to analyze the command line parameters.
in conclusion:
This article introduces three commonly used Java command line processing frameworks: Apache Commons Cli, Picocli, and JCOMMANDER.They provide a series of categories and methods to help us analyze and handle the command line options and parameters, and provide the function of automatically generating help information.According to the needs of the project and personal preferences, choosing a suitable framework can improve the efficiency and maintenance of command line processing.
I hope this article can help you understand and choose the suitable Java command line processing framework!
