Async Servlet Exception

Question

I'm new to JavaEE 6 and I learnt that it support asynchronous servlets called AsyncServlets. So I tried to create a small program using JavaEE6.

Here is my code for the servlet

@WebServlet(name = "AsyncServlet", urlPatterns = {"/AsyncServlet"}, asyncSupported=true)
public class AsyncServlet extends HttpServlet {


    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        AsyncContext aCtx = request.startAsync(request, response);
        Executor executor = Executors.newSingleThreadExecutor();
        executor.execute(new MyClass(aCtx));
        System.out.println("Original thread is freed");
    }




} 

But when I try to run the servlet I get an exception java.lang.IllegalStateException: Not supported. I'm using tomcat 7.0.14 as the server. i did not create a web.xml. Where is the problem in this code?

EDIT:

This is the full stack-trace of the exception

SEVERE: Servlet.service() for servlet [AsyncServlet] in context with path [/AsyncTest] threw exception
java.lang.IllegalStateException: Not supported.
at org.apache.catalina.connector.Request.startAsync(Request.java:1618)
at org.apache.catalina.connector.RequestFacade.startAsync(RequestFacade.java:1031)
at javax.servlet.ServletRequestWrapper.startAsync(ServletRequestWrapper.java:379)
at com.icbt.demo.servlet.AsyncServlet.doGet(AsyncServlet.java:30)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:563)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:399)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:317)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:204)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:311)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662) 

Answer 1

if you use tomcat as your web server then you should maintion that you are going to use asyc request to tomcat

before start async request put this line code

request.setAttribute("org.apache.catalina.ASYNC_SUPPORTED", true);

i hope you can get what u want from it

Answer 2

An IllegalStateException will be thrown if an application tries to start an asynchronous operation and there is a servlet or servlet filter in the request processing chain that does not support asynchronous processing.So there might be have some mistake.plz check your code.