Java Hello World cli using args4j

A simple example of how to use args4j to add command line args to a simple “Hello World” type java application.

For example below command line execution would print “Hello arg4j!” instead of the default “Hello World!” if you don’t pass any args.

$ java -jar helloWorldParamaterized --msg='Hello arg4j!' 
import org.kohsuke.args4j.CmdLineParser;
import org.kohsuke.args4j.Option;
* Hello world! class that is paramaterized (with defaults) using arg4j.
* Example cli usage: java -jar helloWorldParamaterized –msg='Hello arg4j!'
public class helloWorldParamaterized
private String msg = "Hello World!";
public static void main(String[] args) throws Exception {
new helloWorldParamaterized().doMain(args);
public void doMain(String[] args) throws Exception {
// make a parser
CmdLineParser parser = new CmdLineParser(this);
// parse args
// print message passed in from args

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