Commons-CLI Define options using builder

Option class provides builder to define options. If an object has more properties to initialize, builder design pattern is used to instantiate object conveniently.

https://self-learning-java-tutorial.blogspot.com/2016/11/when-to-use-builder-pattern.html

Example

Option option1 = Option.builder("A").longOpt("almost-all").desc("do not list implied . and ..").hasArg(false).build();

Following is the complete working application.

OptionDemo.java

import java.io.OutputStream;
import java.io.PrintWriter;

import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.Options;

public class OptionDemo {

 public static void printHelp(final Options options, final int width, final String cmdLineSyntax,
   final String header, final String footer, final int leftPad, final int descPad, final boolean autoUsage,
   final OutputStream out) {
  PrintWriter writer = new PrintWriter(out);
  final HelpFormatter helpFormatter = new HelpFormatter();
  helpFormatter.printHelp(writer, width, cmdLineSyntax, header, options, leftPad, descPad, footer, autoUsage);
  writer.flush();
 }

 public static void main(String args[]) {

  Option option1 = Option.builder("A").longOpt("almost-all").desc("do not list implied . and ..").hasArg(false).build();
  Option option2 = Option.builder("b").longOpt("block-size").argName("SIZE").desc("use SIZE-byte blocks").hasArg(true).build();
  Option option3 = Option.builder("c").desc("with -lt: sort by, and show, ctime (time of last modification of file status information) with -l:show ctime and sort by name otherwise: sort by ctime").hasArg(false).build();

  Options options = new Options();
  options.addOption(option1).addOption(option2).addOption(option3);

  printHelp(options, 100, "ls", "", "", 5, 5, true, System.out);

 }
}

Output

usage: ls [-A] [-b <SIZE>] [-c]
     -A,--almost-all            do not list implied . and ..
     -b,--block-size <SIZE>     use SIZE-byte blocks
     -c                         with -lt: sort by, and show, ctime (time of last modification of
                                file status information) with -l:show ctime and sort by name
                                otherwise: sort by ctime

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