What is Commons CLI library?

Overview

The Apache Commons CLI library provides an API for parsing command line options passed to Java programs. It also provides support for options available for a command line tool in different formats like POSIX , GNU etc.

More information about the library, please visit : https://commons.apache.org/proper/commons-cli/index.html

Maven dependency:

<!– https://mvnrepository.com/artifact/commons-cli/commons-cli –>

<dependency>
<groupId>commons-cli</groupId>
<artifactId>commons-cli</artifactId>
<version>1.4</version>
</dependency>

 

For other build tools :

https://commons.apache.org/proper/commons-cli/dependency-info.html

Let’s us assume we are developing a sample automation framework which can be run from the command line and accepts command line options for Test Environment and Test type. Test environment could be QA , STAGE or PROD etc. Test Types could be BVT, P1 , Regression etc.

Sample Program Code

CommandLine class represents list of arguments parsed against Options descriptor.

Options class represents a collection of objects, which describe the possible options for a command-line.

CommandLineParser interface: A class that implements this parser interface can parse a String array according to the Options specified and return a command line object.

 

public class CommandLineExample {

private static Options options = null;

private static final String envOption = "e";
 private static final String testOption = "t";
 private static final String helpOption = "h";
 private CommandLine cmd = null; 
 public static String envType ;
 public static String testType ;

static{
 options = new Options();
 options.addOption(envOption, true, 
 "QA or STAGE or PROD");
 options.addOption(testOption, true, "BVT or Regression");
 options.addOption(helpOption, false,"help option");

}



public static void main(String[] args) {
 CommandLineExample cliProg = new CommandLineExample();
 cliProg.loadArgs(args);
 }



private void loadArgs(String[] args){
 //CommandLineParser parser = new PosixParser();
 CommandLineParser parser = new DefaultParser();
 try {
 cmd = parser.parse(options, args);
 } catch (ParseException e) {
 System.err.println("Error parsing arguments");
 e.printStackTrace();
 System.exit(1);
 }

// Check for mandatory arguments

if (!cmd.hasOption(envOption)){
 HelpFormatter formatter = new HelpFormatter();
 formatter.printHelp("java -jar SampleAutomationFramework.jar", options);
 System.exit(1);
 }
 if (!cmd.hasOption(testOption)){
 HelpFormatter formatter = new HelpFormatter();
 formatter.printHelp("java -jar SampleAutomationFramework.jar", options);
 System.exit(1);
 }
 if ( cmd.hasOption(helpOption)){
 HelpFormatter formatter = new HelpFormatter();
 formatter.printHelp("java -jar SampleAutomationFramework.jar", options);
 System.exit(1);
 }



// Look for optional arguments.
 if (cmd.hasOption(envOption)){
 envType = cmd.getOptionValue(envOption);
 System.out.println(envType);}

if (cmd.hasOption(testOption)){
 testType = cmd.getOptionValue(testOption);
 System.out.println(testType);}
 }
}

 

Running the program:

/>java -jar SampleAutomationFramework.jar -h
usage: java -jar SampleAutomationFramework.jar
-e <arg> QA or STAGE or PROD
-h help option
-t <arg> BVT or Regression

/>java -jar SampleAutomationFramework.jar -e QA
usage: java -jar SampleAutomationFramework.jar
-e <arg> QA or STAGE or PROD
-h help option
-t <arg> BVT or Regression

/>
C:\EclipseWorkspace>java -jar SampleAutomationFramework.jar -e QA -t BVT
QA
BVT

 

 

Java Tutorial on this website:

https://www.testingdocs.com/java-tutorial/

For more information on Java, visit the official website :

https://www.oracle.com/in/java/