Webapp with embedded jetty giving exception

Question

I am trying to maintain a java web app that is run standalone using embedded jetty, using Java 7 and Jetty 9.1.3. Everything runs except all of the links in one of the JSP pages. Each link on that page is supposed to fetch a png file or a text file and display it below the link. When run through Netbeans, each link just hangs when clicked and the console gives the following errors:

Apr 10, 2014 4:23:34 PM org.apache.struts.chain.commands.AbstractExceptionHandler execute
WARNING: Unhandled exception
java.lang.IllegalStateException: Form too many keys
at org.eclipse.jetty.util.UrlEncoded.decodeUtf8To(UrlEncoded.java:526)
at org.eclipse.jetty.util.UrlEncoded.decodeTo(UrlEncoded.java:625)
at org.eclipse.jetty.server.Request.extractParameters(Request.java:344)
at org.eclipse.jetty.server.Request.getParameterNames(Request.java:852)
at org.apache.struts.util.RequestUtils.populate(RequestUtils.java:426)
at org.apache.struts.chain.commands.servlet.PopulateActionForm.populate(PopulateActionForm.java:50)
at org.apache.struts.chain.commands.AbstractPopulateActionForm.execute(AbstractPopulateActionForm.java:60)
at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:304)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:711)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:552)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:568)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:221)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1112)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:479)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:183)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1046)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.HandlerList.handle(HandlerList.java:52)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.Server.handle(Server.java:462)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:281)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:232)
at org.eclipse.jetty.io.AbstractConnection$1.run(AbstractConnection.java:505)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:607)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:536)
at java.lang.Thread.run(Thread.java:744)

Apr 10, 2014 4:23:34 PM org.apache.struts.chain.commands.ExceptionCatcher postprocess
WARNING: Exception from exceptionCommand 'servlet-exception'
java.lang.IllegalStateException: Form too many keys
at org.eclipse.jetty.util.UrlEncoded.decodeUtf8To(UrlEncoded.java:526)
at org.eclipse.jetty.util.UrlEncoded.decodeTo(UrlEncoded.java:625)
at org.eclipse.jetty.server.Request.extractParameters(Request.java:344)
at org.eclipse.jetty.server.Request.getParameterNames(Request.java:852)
at org.apache.struts.util.RequestUtils.populate(RequestUtils.java:426)
at org.apache.struts.chain.commands.servlet.PopulateActionForm.populate(PopulateActionForm.java:50)
at org.apache.struts.chain.commands.AbstractPopulateActionForm.execute(AbstractPopulateActionForm.java:60)
at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:304)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:711)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:552)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:568)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:221)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1112)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:479)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:183)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1046)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.HandlerList.handle(HandlerList.java:52)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.Server.handle(Server.java:462)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:281)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:232)
at org.eclipse.jetty.io.AbstractConnection$1.run(AbstractConnection.java:505)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:607)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:536)
at java.lang.Thread.run(Thread.java:744)

2014-04-10 16:23:34.438:WARN:oejs.ServletHandler:qtp2008751570-30: 
javax.servlet.ServletException: java.lang.IllegalStateException: Form too many keys
at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:286)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:711)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:552)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:568)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:221)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1112)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:479)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:183)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1046)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.HandlerList.handle(HandlerList.java:52)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.Server.handle(Server.java:462)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:281)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:232)
at org.eclipse.jetty.io.AbstractConnection$1.run(AbstractConnection.java:505)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:607)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:536)
at java.lang.Thread.run(Thread.java:744)
Caused by: 
java.lang.IllegalStateException: Form too many keys
at org.eclipse.jetty.util.UrlEncoded.decodeUtf8To(UrlEncoded.java:526)
at org.eclipse.jetty.util.UrlEncoded.decodeTo(UrlEncoded.java:625)
at org.eclipse.jetty.server.Request.extractParameters(Request.java:344)
at org.eclipse.jetty.server.Request.getParameterNames(Request.java:852)
at org.apache.struts.util.RequestUtils.populate(RequestUtils.java:426)
at org.apache.struts.chain.commands.servlet.PopulateActionForm.populate(PopulateActionForm.java:50)
at org.apache.struts.chain.commands.AbstractPopulateActionForm.execute(AbstractPopulateActionForm.java:60)
at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:304)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:711)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:552)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:568)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:221)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1112)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:479)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:183)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1046)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.HandlerList.handle(HandlerList.java:52)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.Server.handle(Server.java:462)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:281)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:232)
at org.eclipse.jetty.io.AbstractConnection$1.run(AbstractConnection.java:505)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:607)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:536)
at java.lang.Thread.run(Thread.java:744)

I did some research and found that this often (or always) is related to the form being to large for the default jetty parameters. The fix suggested is to override the defaults by creating an xml file called jetty-web.xml and placing it in the web/WEB-INF folder. Here is my newly created jetty-web.xml:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE Configure PUBLIC
"-//Eclipse//DTD Configure//EN"
"http://jetty.eclipse.org/configure.dtd">

<Configure id="WebAppContext" class="org.eclipse.jetty.webapp.WebAppContext">
   <Set name="maxFormContentSize">600000</Set>
   <Set name="maxFormKeys">20000</Set>
</Configure>

I rebuilt the web app with this file in place and it did not fix the problem. I have tried using larger numbers but it seems to have no effect. I'm not familiar enough with jetty, or even the underlying way that embedded jetty interacts with java, to know what to try next.

I will be happy to post any code from the offending JSP page or the supporting java code that handles requests, but I thought perhaps the console errors would be enough for now. Thanks so much for any help.

Answer 1

try

-Dorg.eclipse.jetty.server.Request.maxFormKeys=2000

in jvm arguments

Answer 2

for jetty 9.2 you can configure the form limits for a sinlge webapplication. In this case the context handler (or webappContext) instance must be configured using the following methods:

ContextHandler.setMaxFormContentSize(int maxSizeInBytes);
ContextHandler.setMaxFormKeys(int formKeys);    

These methods may be called directly when embedding jetty, but more commonly are configured from a context XML file or WEB-INF/jetty-web.xml file:

<Configure class="org.eclipse.jetty.webapp.WebAppContext">

  ...

  <Set name="maxFormContentSize">200000</Set>
  <Set name="maxFormKeys">2000</Set>
</Configure>    

You can configure Form Limits for the Server

If a context does not have specific form limits configured, then the server attributes are inspected to see if a server wide limit has been set on the size or keys. The following XML shows how these attributes can be set in jetty.xml:

<configure class="org.eclipse.jetty.server.Server">

  ...

  <Call name="setAttribute">
    <Arg>org.eclipse.jetty.server.Request.maxFormContentSize</Arg>
    <Arg>100000</Arg>
   </Call>
  <Call name="setAttribute">
    <Arg>org.eclipse.jetty.server.Request.maxFormKeys</Arg>
    <Arg>2000</Arg>
   </Call>
</configure>