The three minor hurdles to configuring Jetty 7 and Maven are making sure port 80 is not already taken, getting the right connector implementation configured, and running Maven as sudo so that Jetty has permission to run on Port 80. In OS X, you can see if anything is already running on port 80 by running the following command from Terminal:

If you're on OS X and see something running on Port 80 yet you didn't install a webserver, chances are it's Sharing. Go to System Preferences > Sharing and disable it. Otherwise, figure out what process is running on port 80 and make it go away.

Now to configure the Jetty Maven plug-in, here is what my configuration looks like which you should replicate in your pom.xml under the plugins section (and adjust to your particular directory structure and desired context):

One of the difficulties I encountered was getting the connector working correctly. Since Maven has moved to be an Eclipse project, the package structure for the connector has changed and thus the reason most of the existing documentation on getting custom connectors to work did not work for me.

The last remaining hurdle to overcome is that running a standard “mvn jetty:run” doesn't work on OS X (and likely Linux as well). You'll see the error message “Embedded error: Permission denied”. If you run Maven with error stacktraces enabled, you'll see an exception that looks like this:

This is because you need elevated permissions to run applications on lower ports on *nix based systems. Simply run it as sudo, “sudo mvn jetty:run” and you'll be good to go.

Not a terribly tough problem to overcome on your own, but I thought I'd try and try to save someone some time if they run across the same issues.

Basically in any Unix type derivative such as Linux such (Ubuntu, RedHat, SuSe, etc.), as well as Mac OS X, all that you need to type this at the command line:

I remember there being a couple of commands in Windows which you could do this with, but it's been so long since I've used Windows on a regular basis I honestly don't remember how to do it. I do know you can use TCPView to accomplish the same thing, however.

... you've came to the right place.

There are many ways to setup your package structure under Maven2 to build EAR's, but essentially what I do is create a root level project which packages a given application into an EAR, and nothing more. Once you have the maven-ear-plugin setup for the most part, all that you need to do is to tell the Maven EAR Plugin to treat the various Axis2 pieces of shit packages like JAR's:

This is just one of many gotcha's I learned about while working on an aforementioned project. In fact it's really pretty hard to find any comprehensive documentation on getting EJB3, Spring, and Hibernate working together on JBoss with a typical Java web application, especially while using Maven. I have a sample project I used to work through some of the integration issues with this, and will hopefully be able to wrap it up and add it to Google Code in the next few weeks to provide an example of getting all of these technologies to play together.

I've been working on a sizable project at work that uses NIO under the hood, but luckily I'm using a 3rd party library which provides the network connectivity for me. It seems that NIO is very hard to implement correctly, but if you can, the performance advantages are definitely worth the effort. I'm only a few days away from starting to do some load testing on my work, so I'll be interested in seeing the performance improvement over the section of code I'm replacing which uses standard IO (not to mention the various synchronization and thread consumption problems I'll be fixing).

Being able to quickly handle a large number of concurrent connections is definitely a requirement for today's AJAX applications, and it's good to see an NIO based connector from someone other than Jetty.

I've always been weary of the MySQL licensing scheme and have used PostgreSQL instead when possible, and if true this would be yet another reason I will continue to choose PostgreSQL over MySQL.