Jetty Server not Working for War with JSPs - jetty

Question

I am trying to create a simple jetty server/container that will take a war file and deploy. This is not embedded jetty with spring-boot.
Here is my build.gradle dependencies:
dependencies {
def jettyVersion = "9.4.34.v20201102"
implementation "org.eclipse.jetty:jetty-server:$jettyVersion"
implementation "org.eclipse.jetty:jetty-security:$jettyVersion"
implementation "org.eclipse.jetty:jetty-servlet:$jettyVersion"
implementation "org.eclipse.jetty:jetty-webapp:$jettyVersion"
implementation "org.eclipse.jetty:jetty-annotations:$jettyVersion"
implementation "org.eclipse.jetty:jetty-jmx:$jettyVersion"
}
Here is my main class:
public static void main(String[] args) throws Exception {
Server server = new Server(8080);
MBeanContainer mbContainer = new MBeanContainer(getPlatformMBeanServer());
server.addBean(mbContainer);
WebAppContext webapp = new WebAppContext();
webapp.setContextPath("/");
webapp.setWar(warFile()); // LOGIC TO UPLOAD WAR FILE
webapp.setExtractWAR(true);
Configuration.ClassList classList = Configuration.ClassList.setServerDefault(server);
classList.addBefore("org.eclipse.jetty.webapp.JettyWebXmlConfiguration",
"org.eclipse.jetty.annotations.AnnotationConfiguration");
webapp.setAttribute("org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern",
".*/[^/]*servlet-api-[^/]*\\.jar$|.*/javax.servlet.jsp.jstl-.*\\.jar$|.*/[^/]*taglibs.*\\.jar$");
server.setHandler(webapp);
server.start();
server.dumpStdErr();
server.join();
}
However, when I try to go to the app (http://localhost:8080/index), I keep getting the following error message:
URI: /index
STATUS: 500
MESSAGE: JSP support not configured
SERVLET: jsp
There is only one line of error message in the console:
2020-12-11 09:49:51.563:INFO:oejshC.ROOT:qtp2025864991-33: No JSP support. Check that JSP jars are in lib/jsp and that the JSP option has been specified to start.jar
What JSP Jars that it is referring to? I am at a loss as to what dependencies I need to add to make it work for JSPs.
Thx.

Answer 1

You will have to add apache-jsp so that your server will support jsps. If your web app uses jstl, you should also add apache-jstl.

Answer 2

For WebAppContext usage (which is a bit easier to setup than ServletContextHandler usage) you'll need the following artifacts ...
https://search.maven.org/artifact/org.eclipse.jetty/apache-jsp (for the Jetty specific JettyJspServlet which extends from the Jasper JspServlet)
https://search.maven.org/artifact/org.eclipse.jetty/apache-jstl (to support Taglibs custom and standard)
Make sure your org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern can reference the apache-jsp artifact properly, otherwise the internal javax.servlet.ServletContextInitializer will not load properly.
If nothing happens by simply adding those artifacts, you'll need to verify your default descriptor setup on your WebAppContext.setDefaultsDescriptor(String) to ensure that you pass in a resource reference (path or uri) to the Jetty default descriptor XML.
https://github.com/eclipse/jetty.project/blob/jetty-9.4.35.v20201120/jetty-webapp/src/main/config/etc/webdefault.xml
Enabling JSP support in embedded mode can be quite tricky if you use the ServletContextHandler instead of the WebAppContext.
If you ever decide to use the ServletContextHandler instead of a WebAppContext (to have a single fat/uber jar, to speed up load/deploy time, to ease unit testing, etc...), then check out the Jetty maintained example project at ...
https://github.com/jetty-project/embedded-jetty-jsp