Executable WARs with Jetty

Executable WARs with Jetty

Today I want to talk about one of the younger members in the Eclipse family: Jetty. It is great to have such an interesting project on board and it is yet another example of how Eclipse has become more than just an IDE.

What I wanted to with jetty was to create an executable, standalone and self-contained WAR. I first encountered this concept in Hudson. The hudson.war contains an embedded Winstone servlet container, which makes it possible to run the application by executing

java -jar hudson.war

This makes test driving the application really simple. The idea was to do the same with Jetty. Embedding the Jetty runtime in the war proved to be the easy part, as it was just a matter of declaring the jetty dependencies in the maven pom.xml.

The tricky part was telling jetty where to find the war-file to serve. My first try was to hardcode the filename, but that left a foul aftertaste. Finding a solution took quite some time, which is why I am posting this for future reference. This is the Main-Class used to bootstrap Jetty (adapted from the Wicket quickstart archetype):

import org.mortbay.jetty.Connector;
import org.mortbay.jetty.Server;
import org.mortbay.jetty.bio.SocketConnector;
import org.mortbay.jetty.webapp.WebAppContext;

public class Start {

  public static void main(String[] args) throws Exception {
    Server server = new Server();
    SocketConnector connector = new SocketConnector();

    // Set some timeout options to make debugging easier.
    connector.setMaxIdleTime(1000 * 60 * 60);
    connector.setSoLingerTime(-1);
    connector.setPort(8080);
    server.setConnectors(new Connector[] { connector });

    WebAppContext context = new WebAppContext();
    context.setServer(server);
    context.setContextPath("/");

    ProtectionDomain protectionDomain = Start.class.getProtectionDomain();
    URL location = protectionDomain.getCodeSource().getLocation();
    context.setWar(location.toExternalForm());

    server.addHandler(context);
    try {
      server.start();
      System.in.read();
      server.stop();
      server.join();
    } catch (Exception e) {
      e.printStackTrace();
      System.exit(100);
    }
  }
}

The interesting bit is the getProtectionDomain()/getCodeSource() part, which tells us the location of the war-file. That’s all there is to it. Presto, executable web-application powered by Jetty in jar.

Edit: Added the import statements as per Tim’s suggestion.