Loading a Grizzly/Jersey server in a JAR

Question

I have a main application in a jar file, and it dynamically loads 'plug-ins', which are separate jar files.

I want one of these plug-ins to be a REST server, so I'm using jersey. The problem is when I load a plug-in with jersey, I can run the http server, but when I go to ../myapp/myresource, I get nothing. The browser hangs.

If I put a main method in the plug-in jar, and run the plug-in directly, it works. The page shows my static text in the browser.

Here is the code in the main.jar that loads plug-ins. I then call Start on each plug-in.

    Vector<IPlugin> plugins = new Vector<IPlugin>();

    // Get all files in directory "plugins"
    File pluginDir = new File("plugins");
    File [] pluginFiles = pluginDir.listFiles();

    for(File file: pluginFiles)
        {
        // Load the file
        URL url = null;
        try
            {
            url = file.toURI().toURL();
            } catch (MalformedURLException e)
            {
            System.out.println("Failed to get URL of .jar file");
            continue;
            }
        ClassLoader loader = URLClassLoader.newInstance(
                new URL[]{url},
                Main.class.getClassLoader());


        // Load the plug-in interface
        try
            {
            Class cPluginClass = Class.forName("com.company.plugin_test.Plugin", true, loader);
            IPlugin plugin = (IPlugin) cPluginClass.newInstance();

            // Success, add the plugin to the plugin list
            plugins.add(plugin);
            }
        catch (Exception e)
            {
            System.out.println(e.toString());
            }
        }

Here is the plug-in code.

public class Plugin
    implements IPlugin
{
private IServer m_server;

public void Start ()
    {
    System.out.println("Loaded the http_plugin");

    String BASE_URI = "http://localhost:8080/myapp/";

    final ResourceConfig rc = new ResourceConfig().packages ("com.company.plugin_test");
    HttpServer httpServer = GrizzlyHttpServerFactory.createHttpServer(URI.create(BASE_URI), rc);

    this.start ();
    }

public void SetServerInterface(IServer server)
    {
    this.m_server = server;
    }

public void Stop ()
    {
    }
}

I'm guessing it's a classloader issue, but I'm new to java (native C++ background). Any ideas? I'll keep chipping away at it.

EDIT //---------------------------- So changing the above jersey code to the following works...

final ResourceConfig rc = new ResourceConfig().register (MyResource.class);

The question is, how do I set the resource config to the current jar context? Also, currently everything has the same package name (com.company.plugin_test).

Answer 1

This worked. I have yet to find a way to do this generically (ie scan all classes in a package or directory). Truth is I won't have that many web resources, so calling each out is fine.

final ResourceConfig rc = new ResourceConfig().register (MyResource.class);