java.lang.NoSuchMethodError: javax.servlet.ServletContext.getEffectiveSessionTrackingModes()Ljava/util/Set;

Question

i want to have a servlet to process inputs from a standalone java program. how to deploy this servlet in jboss. I put the servlet.class file in WEB-INF/classes and in web.xml i gave the servlet url mapping as ".do". From my Java client program i opened connected to the servlet using a URL object. using localhost:8080/.do. BUT i am getting the folowing error:

  ERROR [org.apache.catalina.connector.CoyoteAdapter] An exception or error occurred in the container during the request processing: 
  java.lang.NoSuchMethodError: javax.servlet.ServletContext.getEffectiveSessionTrackingModes()Ljava/util/Set;
            at
     org.apache.catalina.connector.CoyoteAdapter.postParseRequest(CoyoteAdapter.java:567)
            at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:359)
            at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877)
            at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:654)
            at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:951)

web.xml file contents :

<?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN" "java.sun.com/j2ee/dtds/web-app_2_2.dtd">; 
<web-app> 
     <servlet>
         <servlet-name>ReverseServlet</servlet-name> 
         <servlet-class>ReverseServlet</servlet-class> 
     </servlet> 
     <servlet-mapping>
          <servlet-name>ReverseServlet</servlet-name> 
          <url-pattern>/*.do</url-pattern> 
     </servlet-mapping> 
</web-app>

Solution

java.lang.NoSuchMethodError: javax.servlet.ServletContext.getEffectiveSessionTrackingModes()Ljava/util/Set;

This method is introduced in Servlet 3.0. This error can have at least the following causes:

1. Your web.xml is not declared conform at least Servlet 3.0.

2. Your servlet container does not support at least Servlet 3.0.

3. You have servlet container specific libraries of an older version in /WEB-INF/lib.

To solve this problem,

1. Ensure that your web.xml root declaration conforms Servlet 3.0:

   <?xml version="1.0" encoding="UTF-8"?>
   <web-app 
       xmlns="http://java.sun.com/xml/ns/javaee"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
       version="3.0">
   
       <!-- Config here. -->
   
   </web-app>
   

2. Ensure that you're deploying to a Servlet 3.0 compatible container. In case of JBoss AS that would be at least version 6.0.0.

3. Ensure that you don't have those libraries in /WEB-INF/lib. They do not belong there. This is a common beginner's mistake to "solve" compilation errors they faced in their IDE. See also How do I import the javax.servlet API in my Eclipse project?

You've declared your web.xml conform Servlet 2.2. This is definitely wrong. Fix it accordingly.

Comments

[ruakh]

I feel like this is only half the answer. Obviously it's possible to run a Servlet 2.2 app without encountering this exception; it's not as though all sites were perma-broken until Servlet 3.0 was released.

[BalusC]

@ruakh: I'm nowhere telling that this isn't possible. If you're actually unable to run a Servlet 2.2 webapp on a Servlet 3.0 container yourself, then your webapp conflicts point 3 in the answer.

[ruakh]

The OP didn't specify that (s)he was trying to use Servlet 3.0. Your answer even says "You've declared your web.xml conform Servlet 2.2. This is definitely wrong", but I don't see any basis for that. The problem is apparently a version mismatch between two things; your answer is about changing the 2.2 stuff to 3.0, but the OP might actually need the 3.0 stuff changed to 2.2.

[BalusC]

@ruakh: the line <!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN" "java.sun.com/j2ee/dtds/web-app_2_2.dtd"> in OP's web.xml does that.

[ruakh]

No, you misunderstand me. the "You've declared your web.xml conform Servlet 2.2" part is obviously correct; it's the "This is definitely wrong" part that I don't see any basis for.

[ruakh]

(The reason I bring this up is -- I got to this question by Google because of a problem in one of my services. As far as I can tell, it's set up identically to two other services that do work, and all of their web.xml-s say 2.x. So I'm trying to figure out what's wrong with this third service. From your answer, I gather that it's that some sort of 3.0+ has snuck in, but your answer is silent about that possibility or how to address it.)