title: java.lang.IllegalArgumentException: URLDecoder: Incomplete trailing escape () pattern
body: <p>I have a URL like,</p>
  
  <p><code>http://localhost:8080/Project-war/utility/Login.jsf?fallback=%2FProject-war%2Fpublic_resources%2FShowDetails.jsf%3Fid%3D9</code></p>
  
  <p>This URL is formed, when a login page is requested. The return URL to which the request is to be redirected after successful login is appended as a query-string parameter to the URL.</p>
  
  <hr>
  
  <p>If this URL is deliberately changed by a user like so,</p>
  
  <p><code>http://localhost:8080/Project-war/utility/Login.jsf?fallback=%2FProject-war%2Fpublic_resources%2FShowDetails.jsf%3Fid%</code></p>
  
  <p>A few trailing characters have been removed. It is a mal-formed URL. In this case, it causes the following exception to be thrown.</p>
  
  <pre><code>WARNING:   Error invoking requestInitialized method on ServletRequestListener org.jboss.weld.servlet.WeldListener
  java.lang.IllegalArgumentException: URLDecoder: Incomplete trailing escape (%) pattern
      at org.glassfish.grizzly.http.util.URLDecoder.decode(URLDecoder.java:488)
      at org.glassfish.grizzly.http.util.Parameters.processParameters(Parameters.java:654)
      at org.glassfish.grizzly.http.util.Parameters.processParameters(Parameters.java:692)
      at org.glassfish.grizzly.http.util.Parameters.handleQueryParameters(Parameters.java:335)
      at org.glassfish.grizzly.http.server.Request.parseRequestParameters(Request.java:1995)
      at org.glassfish.grizzly.http.server.Request.getParameter(Request.java:1052)
      at org.apache.catalina.connector.Request.getParameter(Request.java:1547)
      at org.apache.catalina.connector.RequestFacade.getParameter(RequestFacade.java:448)
      at org.jboss.weld.servlet.ConversationContextActivator.getConversationId(ConversationContextActivator.java:115)
      at org.jboss.weld.servlet.ConversationContextActivator.activateConversationContext(ConversationContextActivator.java:82)
      at org.jboss.weld.servlet.WeldListener.requestInitialized(WeldListener.java:201)
      at org.apache.catalina.core.StandardContext.fireRequestInitializedEvent(StandardContext.java:5225)
      at org.apache.catalina.core.StandardHostValve.preInvoke(StandardHostValve.java:647)
      at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:166)
      at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:357)
      at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
      at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
      at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
      at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
      at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
      at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
      at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
      at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
      at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
      at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
      at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
      at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
      at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
      at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
      at java.lang.Thread.run(Thread.java:722)
  
  SEVERE:   Error Rendering View[/utility/Login.xhtml]
  java.lang.IllegalStateException: A request must be associated with the context in order to load the known conversations
      at org.jboss.weld.context.AbstractConversationContext.getCurrentConversation(AbstractConversationContext.java:390)
      at org.jboss.weld.jsf.ConversationAwareViewHandler.getActionURL(ConversationAwareViewHandler.java:102)
      at com.sun.faces.renderkit.html_basic.FormRenderer.getActionStr(FormRenderer.java:250)
      at com.sun.faces.renderkit.html_basic.FormRenderer.encodeBegin(FormRenderer.java:143)
      at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:864)
      at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1854)
      at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
      at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
      at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:456)
      at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
      at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
      at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
      at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
      at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
      at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
      at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
      at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:344)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
      at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:70)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
      at filter.LoginNocacheFilter.doFilter(LoginNocacheFilter.java:39)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
      at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316)
      at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
      at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
      at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
      at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
      at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
      at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:357)
      at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
      at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
      at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
      at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
      at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
      at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
      at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
      at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
      at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
      at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
      at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
      at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
      at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
      at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
      at java.lang.Thread.run(Thread.java:722)
  
  WARNING:   Error invoking requestDestroyed method on ServletRequestListener org.jboss.weld.servlet.WeldListener
  java.lang.NullPointerException
      at org.jboss.weld.context.AbstractBoundContext.deactivate(AbstractBoundContext.java:71)
      at org.jboss.weld.context.http.HttpRequestContextImpl.deactivate(HttpRequestContextImpl.java:70)
      at org.jboss.weld.servlet.WeldListener.requestDestroyed(WeldListener.java:154)
      at org.apache.catalina.core.StandardContext.fireRequestDestroyedEvent(StandardContext.java:5261)
      at org.apache.catalina.core.StandardHostValve.postInvoke(StandardHostValve.java:255)
      at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:359)
      at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
      at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
      at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
      at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
      at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
      at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
      at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
      at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
      at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
      at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
      at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
      at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
      at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
      at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
      at java.lang.Thread.run(Thread.java:722)
  </code></pre>
  
  <p>This exception occurs internally and is not caused by the code I wrote. This exception should not occur.</p>
  
  <p>How to tackle/handle this exception?</p>