upload large file error

My application aften error,when upload large file.Recently,this error arise more and more.I can’t find this error in my code.
my code is simple:
private void createUploadUI(final String uploadButton,String title,Upload upload,final ProgressIndicator pIndicator)
{

    upload.setCaption(title);
    upload.setButtonCaption("上传");
    upload.setReceiver(new Upload.Receiver()
    {
        
        @Override
        public OutputStream receiveUpload(String filename, String mimeType)
        {
            // TODO Auto-generated method stub
            return excuteReceiver(filename, mimeType,uploadButton);
        }
    });
    
    upload.addStartedListener(new Upload.StartedListener()
    {
        
        @Override
        public void uploadStarted(StartedEvent event)
        {
            // TODO Auto-generated method stub
        
            pIndicator.setVisible(true);
            pIndicator.setValue(0f);
            
        }
    });
    upload.addFailedListener(new Upload.FailedListener()
    {
        
        @Override
        public void uploadFailed(FailedEvent event)
        {
            // TODO Auto-generated method stub
            pIndicator.setVisible(false);
            
        }
    });
    upload.addProgressListener(new Upload.ProgressListener()
    {
        
        @Override
        public void updateProgress(long readBytes, long contentLength)
        {
            // TODO Auto-generated method stub
            pIndicator.setValue(new Float(readBytes / (float) contentLength));
        }
    });
    upload.addSucceededListener(new Upload.SucceededListener()
    {
        
        @Override
        public void uploadSucceeded(SucceededEvent event)
        {
            // TODO Auto-generated method stub
            excuteSucceeded(event,uploadButton);
        }
    });
}

errors:
Apr 1, 2014 12:12:09 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Flashcloudserver]
in context with path threw exception [com.vaadin.server.ServiceException: ClientAbortException: java.net.SocketException: Broken pipe]
with root cause
java.net.SocketException: Broken pipe
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:109)
at java.net.SocketOutputStream.write(SocketOutputStream.java:153)
at org.apache.coyote.ajp.AjpProcessor.output(AjpProcessor.java:295)
at org.apache.coyote.ajp.AbstractAjpProcessor$SocketOutputBuffer.doWrite(AbstractAjpProcessor.java:1082)
at org.apache.coyote.Response.doWrite(Response.java:533)
at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:383)
at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:462)
at org.apache.catalina.connector.OutputBuffer.doFlush(OutputBuffer.java:334)
at org.apache.catalina.connector.OutputBuffer.close(OutputBuffer.java:283)
at org.apache.catalina.connector.CoyoteOutputStream.close(CoyoteOutputStream.java:108)
at com.vaadin.server.communication.FileUploadHandler.sendUploadResponse(FileUploadHandler.java:643)
at com.vaadin.server.communication.FileUploadHandler.doHandleSimpleMultipartFileUpload(FileUploadHandler.java:402)
at com.vaadin.server.communication.FileUploadHandler.handleRequest(FileUploadHandler.java:280)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1371)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:238)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:701)
Apr 1, 2014 12:27:22 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Flashcloudserver]
in context with path threw exception [com.vaadin.server.ServiceException: java.lang.NullPointerException]
with root cause
java.lang.NullPointerException
at com.vaadin.server.communication.FileUploadHandler.handleRequest(FileUploadHandler.java:266)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1371)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:238)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:701)
Apr 1, 2014 12:28:05 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Flashcloudserver]
in context with path threw exception [com.vaadin.server.ServiceException: ClientAbortException: java.net.SocketException: Broken pipe]
with root cause
java.net.SocketException: Broken pipe
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:109)
at java.net.SocketOutputStream.write(SocketOutputStream.java:153)
at org.apache.coyote.ajp.AjpProcessor.output(AjpProcessor.java:295)
at org.apache.coyote.ajp.AbstractAjpProcessor$SocketOutputBuffer.doWrite(AbstractAjpProcessor.java:1082)
at org.apache.coyote.Response.doWrite(Response.java:533)
at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:383)
at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:462)
at org.apache.catalina.connector.OutputBuffer.doFlush(OutputBuffer.java:334)
at org.apache.catalina.connector.OutputBuffer.close(OutputBuffer.java:283)
at org.apache.catalina.connector.CoyoteOutputStream.close(CoyoteOutputStream.java:108)
at com.vaadin.server.communication.FileUploadHandler.sendUploadResponse(FileUploadHandler.java:643)
at com.vaadin.server.communication.FileUploadHandler.doHandleSimpleMultipartFileUpload(FileUploadHandler.java:402)
at com.vaadin.server.communication.FileUploadHandler.handleRequest(FileUploadHandler.java:280)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1371)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:238)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:701)
Apr 1, 2014 12:30:20 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Flashcloudserver]
in context with path threw exception [com.vaadin.server.ServiceException: java.lang.NullPointerException]
with root cause
java.lang.NullPointerException
at com.vaadin.server.communication.FileUploadHandler.handleRequest(FileUploadHandler.java:266)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1371)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:238)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:701)
Apr 1, 2014 12:44:50 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Flashcloudserver]
in context with path threw exception [com.vaadin.server.ServiceException: ClientAbortException: java.net.SocketException: Broken pipe]
with root cause
java.net.SocketException: Broken pipe
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:109)
at java.net.SocketOutputStream.write(SocketOutputStream.java:153)
at org.apache.coyote.ajp.AjpProcessor.output(AjpProcessor.java:295)
at org.apache.coyote.ajp.AbstractAjpProcessor$SocketOutputBuffer.doWrite(AbstractAjpProcessor.java:1082)
at org.apache.coyote.Response.doWrite(Response.java:533)
at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:383)
at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:462)
at org.apache.catalina.connector.OutputBuffer.doFlush(OutputBuffer.java:334)
at org.apache.catalina.connector.OutputBuffer.close(OutputBuffer.java:283)
at org.apache.catalina.connector.CoyoteOutputStream.close(CoyoteOutputStream.java:108)
at com.vaadin.server.communication.FileUploadHandler.sendUploadResponse(FileUploadHandler.java:643)
at com.vaadin.server.communication.FileUploadHandler.doHandleSimpleMultipartFileUpload(FileUploadHandler.java:402)
at com.vaadin.server.communication.FileUploadHandler.handleRequest(FileUploadHandler.java:280)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1371)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:238)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:701)
Apr 1, 2014 12:50:20 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Flashcloudserver]
in context with path threw exception [com.vaadin.server.ServiceException: java.lang.NullPointerException]
with root cause
java.lang.NullPointerException
at com.vaadin.server.communication.FileUploadHandler.handleRequest(FileUploadHandler.java:266)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1371)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:238)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:701)
Apr 1, 2014 12:50:51 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Flashcloudserver]
in context with path threw exception [com.vaadin.server.ServiceException: java.lang.NullPointerException]
with root cause
java.lang.NullPointerException
at com.vaadin.server.communication.FileUploadHandler.handleRequest(FileUploadHandler.java:266)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1371)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:238)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:701)
Apr 1, 2014 1:12:26 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Flashcloudserver]
in context with path threw exception [com.vaadin.server.ServiceException: java.lang.NullPointerException]
with root cause
java.lang.NullPointerException
at com.vaadin.server.communication.FileUploadHandler.handleRequest(FileUploadHandler.java:266)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1371)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:238)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:701)
Apr 1, 2014 1:27:38 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Flashcloudserver]
in context with path threw exception [com.vaadin.server.ServiceException: ClientAbortException: java.net.SocketException: Broken pipe]
with root cause
java.net.SocketException: Broken pipe
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:109)
at java.net.SocketOutputStream.write(SocketOutputStream.java:153)
at org.apache.coyote.ajp.AjpProcessor.output(AjpProcessor.java:295)
at org.apache.coyote.ajp.AbstractAjpProcessor$SocketOutputBuffer.doWrite(AbstractAjpProcessor.java:1082)
at org.apache.coyote.Response.doWrite(Response.java:533)
at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:383)
at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:462)
at org.apache.catalina.connector.OutputBuffer.doFlush(OutputBuffer.java:334)
at org.apache.catalina.connector.OutputBuffer.close(OutputBuffer.java:283)
at org.apache.catalina.connector.CoyoteOutputStream.close(CoyoteOutputStream.java:108)
at com.vaadin.server.communication.FileUploadHandler.sendUploadResponse(FileUploadHandler.java:643)
at com.vaadin.server.communication.FileUploadHandler.doHandleSimpleMultipartFileUpload(FileUploadHandler.java:402)
at com.vaadin.server.communication.FileUploadHandler.handleRequest(FileUploadHandler.java:280)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1371)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:238)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:701)
Apr 1, 2014 1:30:38 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Flashcloudserver]
in context with path threw exception [com.vaadin.server.ServiceException: java.lang.NullPointerException]
with root cause
java.lang.NullPointerException
at com.vaadin.server.DefaultErrorHandler.findComponent(DefaultErrorHandler.java:95)
at com.vaadin.server.DefaultErrorHandler.findAbstractComponent(DefaultErrorHandler.java:74)
at com.vaadin.server.DefaultErrorHandler.doDefault(DefaultErrorHandler.java:45)
at com.vaadin.server.DefaultErrorHandler.error(DefaultErrorHandler.java:31)
at com.vaadin.server.LegacyCommunicationManager.handleConnectorRelatedException(LegacyCommunicationManager.java:416)
at com.vaadin.server.communication.FileUploadHandler.doHandleSimpleMultipartFileUpload(FileUploadHandler.java:399)
at com.vaadin.server.communication.FileUploadHandler.handleRequest(FileUploadHandler.java:280)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1371)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:238)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:701)

I use vaadin7.1.5