java.lang.VerifyError: Expecting a stackmap frame

Is there a way to load a custom HttpServlet to GAE? I uploaded a project that included an HttpServlet in the .server package and added it to the web.xml...

<servlet>
   <servlet-name>testServlet</servlet-name>
   <servlet-class>gwtone.server.TestServlet</servlet-class>
</servlet>

<servlet-mapping>
   <servlet-name>testServlet</servlet-name>
   <url-pattern>/tester/greet</url-pattern>
</servlet-mapping>

Is there something else I am missing, or is it not possible?

--------EDIT--------

some things that appear when i init my server, which im not used to seeing...

Jan 22, 2012 4:23:44 AM com.google.apphosting.utils.jetty.JettyLogger info
INFO: Logging to JettyLogger(null) via com.google.apphosting.utils.jetty.JettyLogger
Jan 22, 2012 4:23:44 AM com.google.apphosting.utils.config.AppEngineWebXmlReader readAppEngineWebXml
INFO: Successfully processed E:\Program Files\eclipse-SDK-3.7.1-win32-x86_64\Workspace\gwtone\war\WEB-INF/appengine-web.xml
Jan 22, 2012 4:23:44 AM com.google.apphosting.utils.config.AbstractConfigXmlReader readConfigXml
INFO: Successfully processed E:\Program Files\eclipse-SDK-3.7.1-win32-x86_64\Workspace\gwtone\war\WEB-INF/web.xml
Jan 21, 2012 10:23:44 PM com.google.appengine.tools.development.DevAppServerImpl start
INFO: The server is running at http://localhost:8888/
Jan 21, 2012 10:23:44 PM com.google.appengine.tools.development.DevAppServerImpl start
INFO: The admin console is running at http://localhost:8888/_ah/admin

and here is what shows when it crashes..

WARNING: Error for /tester/greet
java.lang.VerifyError: Expecting a stackmap frame at branch target 14 in method gwtone.server.TestServlet.doGet(Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;)V at offset 0
    at java.lang.Class.getDeclaredConstructors0(Native Method)
    at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
    at java.lang.Class.getConstructor0(Unknown Source)
    at java.lang.Class.newInstance0(Unknown Source)
    at java.lang.Class.newInstance(Unknown Source)
    at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153)
    at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:428)
    at org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:339)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:35)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:60)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:122)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
    at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:78)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:362)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

EDIT #2

package gwtone.server;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class TestServlet extends HttpServlet {

public TestServlet(){}

@Override
public void doGet(HttpServletRequest req, HttpServletResponse resp) 
        throws ServletException, IOException {
    System.out.println("0");
    try {
        System.out.println("1");
        resp.getWriter().println("IT WORKED");
        resp.getWriter().flush();
        System.out.println("2");
    } catch (IOException e) {
        e.printStackTrace();
    }
    System.out.println("3");
}
}

As BalusC pointed out, one solution to the problem is to just use JDK6.

Another solution, if you want to stay with JDK7, would be to use "-XX:-UseSplitVerifier" as an argument for the VM. Go to

Window → Preferences → Java → Installed JREs → Edit... → Default VM arguments

and add it there.

Installed JREsJRE Definition


GAE uses Java 1.6, but you've compiled the code with Java 1.7. You need to recompile with Java 1.6. As per the comments, you're using Eclipse; you can set the Java compiler level in Java > Compiler section of project's properties.

enter image description here


Using -XX:-UseSplitVerifier is a temporary solution. Now java uses the previous version of the bytecode verifier which tolerates this bad or missing stackmap frames. Java8 doesnt support this option.