Embedded Jetty Server - NO JSP Support for /, did not find org.apache.jasper.servlet.JspServlet

Question

I've have the following code to use an embedded Jetty server alongside a simple servlet and .jsp webpage. However, after compiling and running the code:

javac -cp lib/servlet-api.jar:lib/jetty-all.jar com/test/MyServlet.java 
javac -cp lib/servlet-api.jar:lib/jetty-all.jar com/test/ServerMain.java 
java -cp .:lib/servlet-api.jar:lib/jetty-all.jar com/test/ServerMain

I get an error:

INFO:oejw.StandardDescriptorProcessor:main: NO JSP Support for /, did not find org.apache.jasper.servlet.JspServlet

And navigating to /index.jsp gives a 500 error.

HTTP ERROR 500
Problem accessing /index.jsp. 
Reason:
JSP support not configured

I've read this post but I don't think the solution applies here because I'm running Jetty embedded rather than using the start.jar.

How can I resolve this error so that the server will run and serve .jsp pages successfully?

ServerMain.java

package com.test;

import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.webapp.WebAppContext;

public class ServerMain {

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

        Server server = new Server(8080);
        WebAppContext webApp = new WebAppContext();
        webApp.setDescriptor("web.xml");
        webApp.setResourceBase("");
        webApp.setParentLoaderPriority(true);
        server.setHandler(webApp);

        try {
            server.start();
        } catch (Exception e) {
            e.printStackTrace();
            System.exit(-1);
        }
        server.join();
    }
}

MyServlet.java

package com.test;

import java.io.IOException;
import java.util.Properties;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MyServlet extends HttpServlet {
    @Override
    public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {

        resp.setContentType("text/plain");
        resp.getWriter().println("Hello, this is a testing servlet. \n\n");
        Properties p = System.getProperties();
        p.list(resp.getWriter());

    }
}

web.xml

   <?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE web-app PUBLIC "-//Oracle Corporation//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd">

<web-app xmlns="http://java.sun.com/xml/ns/javaee" version="2.5">
    <servlet>
        <servlet-name>MyServlet</servlet-name>
        <servlet-class>com.test.MyServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>MyServlet</servlet-name>
        <url-pattern>/test</url-pattern>
    </servlet-mapping>
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
</web-app>

This is my project structure:

webapp
----com
    ----test
        ----MyServlet.java
        ----ServerMain.java
        ----index.jsp
        ----web.xml
----lib
    ----jetty-all.jar
    ----servlet-api.jar  

Solution 1

It seems like you're missing an JAR-file that includes the class org.apache.jasper.servlet.JspServlet. Download a JAR file containing it (look here) and add it to your classpath. Also, on a side note, you should replace com/test/ServerMain with the real class name, com.test.ServerMain. You java statement should look like this:

java -cp ".:lib/servlet-api.jar:lib/jetty-all.jar:lib/apache-jasper.jar" com.test.ServerMain

Solution 2

Haven't tried for embedded Jetty but when running Jetty 9.3 as a service you need to add JSP support.

cd $JETTY_BASE
$JAVA_HOME/bin/java -jar $JETTY_HOME/start.jar --add-to-startd=jsp

Where JETTY_BASE is your folder where you deploy application which is separate from JETTY_HOME. So I'm guessing embedded Jetty would need similar configuration.

Solution 3

Incidentally, there's a github project, maintained by the Jetty Project, demonstrating JSP support in Jetty Embedded.

https://github.com/jetty-project/embedded-jetty-jsp