jetty-maven-plugin:11.0.0 not picking up @WebServlet

[wh81752]

Jetty version
11.0.0

Java version

$ java -version
openjdk version "11.0.8" 2020-07-14
OpenJDK Runtime Environment GraalVM CE 20.2.0 (build 11.0.8+10-jvmci-20.2-b03)
OpenJDK 64-Bit Server VM GraalVM CE 20.2.0 (build 11.0.8+10-jvmci-20.2-b03, mixed mode, sharing)

OS type/version

$ uname -a
Darwin MacBook-Pro.fritz.box 19.6.0 Darwin Kernel Version 19.6.0: Tue Jan 12 22:13:05 PST 2021; root:xnu-6153.141.16~1/RELEASE_X86_64 x86_64

Description
I have a (simple) Servlet 3.0 servlet, i.e. @WebServlet instead of web.xml. I use jetty-maven-plugin to test my servlet during development.

This works as expected using Jetty version 9.4.36.v20210114 and 10.0.0. It does not work any longer using Jetty 11.0.0. It looks like @WebServlet is not picked up:

> mvn clean package jetty:run
[..]
[INFO] --- jetty-maven-plugin:11.0.0:run (default-cli) @ cxf-spring ---
[INFO] Configuring Jetty for project: CXF Spring Demo
[INFO] Classes = /Users/geronimo1/ws/cxf-samples/java_first_spring_support/target/classes
[INFO] Context path = /
[INFO] Tmp directory = /Users/geronimo1/ws/cxf-samples/java_first_spring_support/target/tmp
[INFO] web.xml file = null
[INFO] Webapp directory = /Users/geronimo1/ws/cxf-samples/java_first_spring_support/src/main/webapp
[INFO] Web defaults = org/eclipse/jetty/webapp/webdefault.xml
[INFO] Web overrides =  none
[INFO] jetty-11.0.0; built: 2020-12-02T21:37:29.286Z; git: 432f896d7a4555fcc81f38108757ea0aca8788e6; jvm 11.0.8+10-jvmci-20.2-b03
[WARNING] javax.activation.ActivationDataFlavor scanned from multiple locations: jar:file:///Users/geronimo1/.m2/repository/com/sun/activation/jakarta.activation/1.2.2/jakarta.activation-1.2.2.jar!/javax/activation/ActivationDataFlavor.class, jar:file:///Users/geronimo1/.m2/repository/jakarta/activation/jakarta.activation-api/1.2.2/jakarta.activation-api-1.2.2.jar!/javax/activation/ActivationDataFlavor.class
[... many further warnings, all (?) related to jakarta.activation-api ..]
Feb 10, 2021 10:56:31 PM org.eclipse.jetty.util.log.Log initialized
INFO: Logging initialized @8292ms to org.eclipse.jetty.util.log.Slf4jLog
[INFO] Session workerName=node0
[INFO] Started o.e.j.m.p.MavenWebAppContext@52035328{/,[file:///Users/geronimo1/ws/cxf-samples/java_first_spring_support/src/main/webapp/],AVAILABLE}{file:///Users/geronimo1/ws/cxf-samples/java_first_spring_support/src/main/webapp/}
[INFO] Started ServerConnector@2ec23ec3{HTTP/1.1, (http/1.1)}{0.0.0.0:9002}
[INFO] Started Server@2d3bb944{STARTING}[11.0.0,sto=0] @8444ms
[INFO] Scan interval ms = 1000

The jetty-maven-plugin is really basic:

            <plugin>
                <groupId>org.eclipse.jetty</groupId>
                <artifactId>jetty-maven-plugin</artifactId>
<!--                <version>9.4.36.v20210114</version>-->
<!--                <version>10.0.0</version>-->
                <version>11.0.0</version>
                <configuration>
                    <scan>1000</scan>       <!-- changed from 10.x to 11.x for unkown reason -->
                    <httpConnector>
                        <port>9002</port>
                    </httpConnector>
                </configuration>
            </plugin>

[wh81752]

A reference project demonstrating the problem is available here: https://github.com/wh81752/cxf-spring-servlet/tree/servlet-3.0 => The problem is shown when changing fom version 10.0.0 to 11.0.0

[joakime]

Jetty 11 is based on Jakarta Servlet 5.0

That means you have to use the jakarta.servlet.annotation.WebServlet annotation (look at the package namespace)

https://github.com/eclipse-ee4j/servlet-api/blob/5.0.0-RELEASE/api/src/main/java/jakarta/servlet/annotation/WebServlet.java

There is no backward compatibility with javax.servlet.annotation.WebServlet (notice the package namespace difference?)

The old javax.servlet namespace is dead. There will never be another update or release under that namespace.
Oracle got rid of the entire Java EE project, and moved it over to the Eclipse Foundation a few year ago.
The old namespaces starting with "javax" are not allowed to be used by the Eclipse Foundation (so says Oracle lawyers) going forward.
So that means we got the new namespace starting with jakarta.* to work with.

[joakime]

Some more information about this change ..

• https://www.eclipse.org/community/eclipse_newsletter/2019/may/jakartafuture.php
• https://www.eclipse.org/community/eclipse_newsletter/2019/may/javax.php
• https://www.eclipse.org/community/eclipse_newsletter/2020/may/1.php
• https://eclipse-foundation.blog/2020/12/08/jakarta-ee-9-delivers-the-big-bang/
• https://www.infoworld.com/article/3600158/enterprise-java-gets-a-new-namespace.html

[wh81752]

That means you have to use the jakarta.servlet.annotation.WebServlet annotation (look at the package namespace)

Ahhhh, the namespace of course. Didn't think one second on that, my Intellij even hides all import statements.

The old namespaces starting with "javax" are not allowed to be used by the Eclipse Foundation (so says Oracle lawyers) going forward.

I wonder whether it would also be disallowed to scan for the presence of javax.* annotations and log warnings about being ignored?

So that means we got the new namespace starting with jakarta.* to work with.
All fine if that jakarta.* namespace stays forever.

Anyway, thx for your swift & helpfull response and let's close this issue.