Eclipse, tomcat, 404 error

Question

I am learning servlets and follow this tutorial (I follow step by step but I named the project "SampleServlet" instead of "de.vogella.wtp.filecounter"). When I start the server (step 5.4) I get 404 page error:

HTTP Status 404 - /SampleServlet/servlet/de.vogella.wtp.filecounter.servlets.FileCounter
type Status report
message /SampleServlet/servlet/de.vogella.wtp.filecounter.servlets.FileCounter
description The requested resource (/SampleServlet/servlet/de.vogella.wtp.filecounter.servlets.FileCounter) is not available.

Where to start debugging? There were several "INFO" in the console when server started and one warning:

29.08.2011 21:03:44 org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:SampleServlet' did not find a matching property.

Do I need to change any preferences?

Solution 1

The tutorial is suggesting you to invoke it by http://localhost:8080/de.vogella.wtp.filecounter/FileCounter. The project name defaults to context name de.vogella.wtp.filecounter which you've changed to SampleServlet, so you need to invoke the servlet by http://localhost:8080/SampleServlet/FileCounter.

See also:

• Our Servlets wiki page

---

As to the SetPropertiesRule warning, just ignore it, that's normal. Eclipse is just adding an extra attribute to Tomcat's <Context> element to be able to associate the deployed webapp with a particular project. Tomcat is just jerking because it don't recognize it as one of the predefined <Context> attributes. It's however trying to be helpful for the case the enduser actually made a typo and so on. Just ignore it. You won't see it when you export the webapp and deploy it on a real production server.

Solution 2

Okay according to your web.xml it seems like you're missing a servlet definition and a servlet-mapping. I Don't know why this is not generated by your ide. It should be something like this:

<servlet>
    <servlet-name>SampleServlet</servlet-name>
    <servlet-class>your.package.SampleServlet</servlet-class> <!-- The full qualified package path to your Servlet class -->        
</servlet>

<servlet-mapping> 
    <servlet-name>SampleServlet</servlet-name>
    <url-pattern>/mysample</url-pattern>
</servlet-mapping>

In the servlet-mapping Element you just map any url to your servlet defined above. So if you now call http://yourserver:8080/projectname/mysample the Servlet your.package.SampleServlet will be called.

I hope that helps.

Comments

[BalusC]

Please note that the OP posted the web.xml of Tomcat itself, not of the webapp.

[bancer]

When I right click on the FileCounter.java file in the Project Explorer tab and select "Run As"->"Run on Server" the internal browser opens localhost:8080/SampleServlet/servlet/… with 404 error. localhost:8080/SampleServlet/FileCounter results with the same error.

[bancer]

Super! That works! I wonder why these changes in web.xml file were not generated by Eclipse.

[BalusC]

Please note that you should not edit the web.xml of the server! You should edit or create the one of your webapp.

[BalusC]

I now understand why you run into problems. That tutorial is targeted on Servlet 2.5 while you've created a Servlet 3.0 project which by default get built without web.xml. You would need the @WebServlet annotation instead. Put this line @WebServlet(urlPatterns={"/FileCounter"}) on top of the servlet class declaration. And please, undo all changes you made in Tomcat's own web.xml. This is not the right way to declare your own servlets, it makes your webapp unportable!

[Chris]

Yes BalusC is right! Look for the web.xml file located in your project directory under WEB-INF/web.xml.

[boettger1]

@BalusC's answer brought me back from the brink of suicide. When creating the servlet from WebContent, simply don't overwrite the auto-generated @WebServlet("/FileCounter") annotation in the servlet class. What I'm still puzzled by is why Eclipse (Indigo) is not appending /FileCounter to the URL... why do we have to add it manually?