How to use the "command line parameter parser" framework in the Java library for parameter analysis
How to use the "command line parameter parser" framework in the Java library for parameter analysis
Overview:
Command line parameter analysis is a task that often needs to be processed when developing Java applications.In order to simplify the process of parameter analysis, the Java class library provides many excellent "command line parameter parsers" framework.This article will introduce how to use these frameworks to analyze the command line parameters.
1. Apache Commons Cli framework
Apache Commons Cli is a powerful command line parameter parser, which provides a set of simple and intuitive APIs to resolve and handle command line parameters.
1. Introduce dependencies
First, the dependency item of the Apache Commons Cli needs to be introduced in the project.Add the following code to the pom.xml file:
<dependency>
<groupId>commons-cli</groupId>
<artifactId>commons-cli</artifactId>
<version>1.4</version>
</dependency>
2. Create Options objects
In the Java code, the Options object is first to define the option to define the command line parameters.In the following examples, we define three options: -C, -F and -H.
Options options = new Options();
options.addOption("c", "create", false, "Create something");
options.addOption("f", "file", true, "Specify a file");
options.addOption("h", "help", false, "Show help");
3. Create CommandLineParser objects and analyze command line parameters
Next, create a CommandLineParser object and use the object to analyze the command line parameters.In the following example, we use defaultParser to analyze the parameters.
CommandLineParser parser = new DefaultParser();
CommandLine cmd = parser.parse(options, args);
4. Processing the results of the analysis
Finally, process the corresponding logic based on the analytic results.In the following example, we execute the corresponding logic according to the option.
if (cmd.hasOption("c")) {
// Execute the creation logic
}
if (cmd.hasOption("f")) {
String file = cmd.getOptionValue("f");
// Use files to operate
}
if (cmd.hasOption("h")) {
// Display help information
}
Second, JCOMMANDER framework
JCOMMANDER is another popular command line parameter parser framework. It provides simple and robust APIs to analyze and process command line parameters.
1. Introduce dependencies
First, the dependencies of the JCOMMANDER framework need to be introduced in the project.Add the following code to the pom.xml file:
<dependency>
<groupId>com.beust</groupId>
<artifactId>jcommander</artifactId>
<version>1.81</version>
</dependency>
2. Create a parameter model class
In the Java code, a parameter model class is created to define the command line parameters.In the following example, we define a parameter model class containing multiple options.
public class MyArgs {
@Parameter(names = {"-c", "--create"}, description = "Create something")
public boolean create;
@Parameter(names = {"-f", "--file"}, description = "Specify a file")
public String file;
@Parameter(names = {"-h", "--help"}, description = "Show help")
public boolean help;
}
3. Analyze the command line parameters
Next, use JCOMMANDER to parse the command line parameters.In the following example, we created a MyARGS object and passed ARGS to JCOMMANDER to parse the parameters.
MyArgs myArgs = new MyArgs();
JCommander jCommander = new JCommander(myArgs);
jCommander.parse(args);
4. Processing the results of the analysis
Finally, process the corresponding logic based on the analytic results.In the following example, we execute the corresponding logic according to the option.
if (myArgs.create) {
// Execute the creation logic
}
if (myArgs.file != null) {
String file = myArgs.file;
// Use files to operate
}
if (myArgs.help) {
// Display help information
}
in conclusion:
This article introduces two command line parameter parser frameworks using the Java library: Apache Commons Cli and JCOMMANDER.By using these frameworks, the process of analysis of the command line parameters can be simplified, the development workload is reduced, and the readability and maintenance of the code can be improved.By using the command line parameter parser framework, Java applications can be developed more efficiently.
