Can't get Jetty to scan for annotated classes

Question

I have an application with an embedded jetty server which I'm starting up like this (placed in main() and launched with eclipse):

Server server = new Server(port);

WebAppContext context = new WebAppContext();
context.setResourceBase("web/");
context.setDescriptor("web/WEB-INF/web.xml");
context.setConfigurations(new Configuration[]{
            new AnnotationConfiguration(), new WebXmlConfiguration(),
            new WebInfConfiguration(), new TagLibConfiguration(),
            new PlusConfiguration(), new MetaInfConfiguration(),
            new FragmentConfiguration(), new EnvConfiguration()});

context.setContextPath("/");
context.setParentLoaderPriority(true);
server.setHandler(context);
server.start();
server.join();

My web.xml looks like this (empty for now, I'm not sure if I can remove it completely):

<web-app 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    metadata-complete="false"
    version="3.0">
</web-app>

And I have a simple class set up like this:

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet(urlPatterns={"/test"})
public class TestServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException  {
        request.getRequestDispatcher("/WEB-INF/html/index.html").forward(request,response);
    }
}

My application works fine when I use traditional servlet mappings in web.xml. But when I remove the web.xml mappings and use annotations, I only get 404s. It doesn't look like it's scanning for annotations at all. The console looks like this:

2012-08-01 17:40:37.021:INFO:oejs.Server:jetty-8.1.5.v20120716
2012-08-01 17:40:37.227:INFO:oejpw.PlusConfiguration:No Transaction manager found - if your webapp requires one, please configure one.
2012-08-01 17:40:37.294:INFO:oejsh.ContextHandler:started o.e.j.w.WebAppContext{/,file:/Users/me/project/web/}
2012-08-01 17:40:37.547:INFO:oejsh.ContextHandler:started o.e.j.w.WebAppContext{/,file:/Users/me/project/web/}
2012-08-01 17:40:37.547:INFO:oejsh.ContextHandler:started o.e.j.w.WebAppContext{/,file:/Users/me/project/web/}
2012-08-01 17:40:37.547:INFO:oejsh.ContextHandler:started o.e.j.w.WebAppContext{/,file:/Users/me/project/web/}
2012-08-01 17:40:37.641:INFO:oejs.AbstractConnector:Started SelectChannelConnector@0.0.0.0:8080

Some things that I have checked already from my research:

servlet-3.0 jar is in the classpath
metadata-complete set to false in web.xml
I made sure to include AnnotationConfiguration in web app context

I've run out of ideas and am about to just revert back to the old web.xml, but it's killing me why I can't get this to work.

Not for me (Jetty 9.0). Same as @user1569803, and all dependencies in place. I'm investigating alternate routes. — LSerni, Oct 14 '13 at 00:04
Unfortunately I no longer have access to the project which had this issue, so I can't verify the answer for my situation. If some old co-workers try the solution and have success, I'll mark the answer for them. — Ryan Silva, Oct 18 '13 at 01:19

Joakim Erdfelt · Answer 1 · 2021-11-12T12:02:15.593

Update: June 2021

The example project has been updated to be Jetty version neutral.

https://github.com/jetty-project/embedded-servlet-server

It has branches for specific versions of Jetty now.

The older example projects have been archived.

Update: June 2015

The example project has been updated for Jetty 9 and Servlet 3.1

See: https://github.com/jetty-project/embedded-servlet-3.1

Original Answer:

From your description, and a sample project I whipped up using your code, you are doing everything correctly.

Sample project: https://github.com/jetty-project/embedded-servlet-3.0

In order for this to work, you'll want the following (only mentioning this as your question didn't include this detail)

JDK 1.6+
jetty-webapps jar (+ dependencies) from Jetty 8.1.x (or newer)
jetty-annotations jar (+ dependencies) from Jetty 8.1.x (or newer)

Just from these limited requirements you'll see the following list of dependencies present.

$ mvn dependency:tree
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building sample-webapp 1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-dependency-plugin:2.1:tree (default-cli) @ sample-webapp ---
[INFO] com.company.sample:sample-webapp:war:1-SNAPSHOT
[INFO] +- org.eclipse.jetty.orbit:javax.servlet:jar:3.0.0.v201112011016:provided
[INFO] +- org.eclipse.jetty:jetty-webapp:jar:8.1.5-SNAPSHOT:test
[INFO] |  +- org.eclipse.jetty:jetty-xml:jar:8.1.5-SNAPSHOT:test
[INFO] |  |  \- org.eclipse.jetty:jetty-util:jar:8.1.5-SNAPSHOT:test
[INFO] |  \- org.eclipse.jetty:jetty-servlet:jar:8.1.5-SNAPSHOT:test
[INFO] |     \- org.eclipse.jetty:jetty-security:jar:8.1.5-SNAPSHOT:test
[INFO] |        \- org.eclipse.jetty:jetty-server:jar:8.1.5-SNAPSHOT:test
[INFO] |           +- org.eclipse.jetty:jetty-continuation:jar:8.1.5-SNAPSHOT:test
[INFO] |           \- org.eclipse.jetty:jetty-http:jar:8.1.5-SNAPSHOT:test
[INFO] |              \- org.eclipse.jetty:jetty-io:jar:8.1.5-SNAPSHOT:test
[INFO] \- org.eclipse.jetty:jetty-annotations:jar:8.1.5-SNAPSHOT:test
[INFO]    +- org.eclipse.jetty:jetty-plus:jar:8.1.5-SNAPSHOT:test
[INFO]    |  +- org.eclipse.jetty.orbit:javax.transaction:jar:1.1.1.v201105210645:test
[INFO]    |  \- org.eclipse.jetty:jetty-jndi:jar:8.1.5-SNAPSHOT:test
[INFO]    |     \- org.eclipse.jetty.orbit:javax.mail.glassfish:jar:1.4.1.v201005082020:test
[INFO]    |        \- org.eclipse.jetty.orbit:javax.activation:jar:1.1.0.v201105071233:test
[INFO]    +- org.eclipse.jetty.orbit:javax.annotation:jar:1.1.0.v201108011116:test
[INFO]    \- org.eclipse.jetty.orbit:org.objectweb.asm:jar:3.1.0.v200803061910:test
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.771s
[INFO] Finished at: Fri Aug 10 18:17:46 MST 2012
[INFO] Final Memory: 6M/180M
[INFO] ------------------------------------------------------------------------

It is quite likely that you are just missing a dependency or JDK requirement.

I had the same problem and your answer solved it; I was missing jetty-annotations on classpath AND I didn't have the appropriate `Configuration` set (AnnotationConfiguration). Thanks! — Merchuk Hul, Aug 26 '14 at 07:45

score 8 · Answer 2 · answered Oct 06 '14 at 16:31

AnntationConfiguration class scans annotations via its scanForAnnotations(WebAppContext) method. In the method AnnotationConfiguration class scans following path.

container jars
WEB-INF/classes
WEB-INF/libs

So if you want your servlet classes in your production code(i.e. the sources in the directory src/main/java) to be scanned, add your production code into the WebAppContext's metadata as WEB-INF/classes.

Try the code bellow, for adding your code into WebAppContext's metadata.

URL classes = getClass()
        .getProtectionDomain()
        .getCodeSource()
        .getLocation();

WebAppContext context = new WebAppContext();
context.getMetaData()
    .setWebInfClassesDirs(
        Arrays.asList(Resource.newResource(classes)));

score 5 · Answer 3 · answered Nov 03 '13 at 00:41

I had this same problem, but after many reads I got the solution! IMPORTANT: remember to have in your build path the following jars:

jetty-all-9.0.6.v20130930.jar

jetty-annotations-9.0.6.v20130930.jar

org.objectweb.asm-3.1.0.v200803061910.jar

javax.servlet-api-3.0.1.jar

jetty-plus-9.0.6.v20130930.jar

public class Main {

   public static void main(String[] args) throws Exception {

       //Create the server
       Server server = new Server(8080);

       ClassList clist = ClassList.setServerDefault(server);

       //clist.addAfter("org.eclipse.jetty.webapp.FragmentConfiguration", "org.eclipse.jetty.plus.webapp.EnvConfiguration",    "org.eclipse.jetty.plus.webapp.PlusConfiguration");
       clist.addBefore(JettyWebXmlConfiguration.class.getName(), AnnotationConfiguration.class.getName());

       //Here is the trick to scan current classpath!
       webapp.setAttribute("org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern", 
            ".*/build/classes/");

       webapp.setContextPath("/");
       webapp.setResourceBase("./WebContent");


       server.setHandler(webapp);

       server.start();
       server.join();

   }

}

More details on [ContainerIncludeJarPattern](http://eclipse.org/jetty/documentation/current/configuring-webapps.html#container-include-jar-pattern) — ursa, May 16 '15 at 17:41
for me it works though the webapp variable is not defined! I got it working because the webapp is an instance of org.eclipse.jetty.webapp.WebAppContext — Dirk Schumacher, Nov 11 '16 at 09:58

score 1 · Answer 4 · answered Aug 03 '14 at 09:41

Based on the previous example provided by Joakim, I've uploaded a modified version that supports annotations in an embedded jetty without packaging the project into a war file. This project is ready to deploy to Heroku just running:

$java -cp target/classes:"target/dependency/*" com.example.Launcher

If you are interested in the details, the important lines are these ones from com.example.Launcher:

context.setConfigurations(new Configuration[] {
            new AnnotationConfiguration(), new WebXmlConfiguration(),
            new WebInfConfiguration(),
            new PlusConfiguration(), new MetaInfConfiguration(),
            new FragmentConfiguration(), new EnvConfiguration() });

// Important! make sure Jetty scans all classes under ./classes looking for annotations. 
//'Classes' directory is generated running 'mvn package'
context.setAttribute("org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern",".*/classes/.*");

You can change accordingly the JarPattern depending on the classes you want to scan for annotations.

Here you have the full example: https://github.com/pablormier/embedded-jetty-annotations-example

The line context.setAttribute("org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern",".*/classes/.*"); was the key for me. Just setup the configurations didn't work. Thanks. — reinaldoluckman, Sep 25 '14 at 16:14

score 1 · Answer 5 · answered Mar 03 '16 at 12:45

I have come up with a different approach rather specific to Jetty & Spring. Instead of letting Jetty scan for classes, I manually called initializer classes in startContext() method of a custom Jetty ServletContextHandler. Code is as follows:

public class CustomServletContextHandler extends ServletContextHandler {

   @Override
   protected void startContext() throws Exception {

       SpringServletContainerInitializer initer = new SpringServletContainerInitializer();

        HashSet<Class<?>> classes = new HashSet<>();
        // Add annotated classes here such as
        //classes.add(SpringSecurityInitializer.class);
        //classes.add(SpringWebInitilializer.class);

        try {
            initer.onStartup(classes, this.getServletContext());
        }catch(Exception e)
        {
            e.printStackTrace();
        }

        super.startContext();
    }
}

And then when creating context, use custom handler:

 ServletContextHandler ctx = new CustomServletContextHandler();
 ctx.setContextPath("/");
 ...

score 1 · Answer 6 · edited Feb 02 '20 at 01:29

You can

provide EmptyResource.INSTANCE if you do not need static resources

add AnnotationConfiguration and override scanForAnnotations method, adding classpath resource to WebAppContext Metadata, possibly with path to root package for a scan

WebAppContext webapp = new WebAppContext();
    webapp.setContextPath("/");
    webapp.setBaseResource(EmptyResource.INSTANCE);
    webapp.setConfigurations(new Configuration[]{
            new AnnotationConfiguration(){
                @Override
                protected void scanForAnnotations(WebAppContext context) throws Exception {
                    Resource classPathResource =    Resource.newResource(EmbeddedServerApp.class.getResource("/my/learn/jetty/servlet").toURI());
                    context.getMetaData().addContainerResource(classPathResource);
                    super.scanForAnnotations(context);
                }
            },
    });
    server.setHandler(webapp);
    server.start();

score 0 · Answer 7 · answered Oct 17 '14 at 09:41

In our case these lines helped in Jetty startup code:

    ClassList cl = Configuration.ClassList.setServerDefault(server);
    cl.addBefore("org.eclipse.jetty.webapp.JettyWebXmlConfiguration", "org.eclipse.jetty.annotations.AnnotationConfiguration");

Can't get Jetty to scan for annotated classes

7 Answers7

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