Salve a tutti.
Sto facendo un progetto j2ee, ora, ho una servlet che mi crea un pdf e lo butta in output.
uso il getOutputStrem per far in modo che compaia il salva con nome nel browser.


codice:
          
..code..    
esponse.setContentType("application/pdf");
response.setHeader("Content-Disposition","attachment; filename=Report_utenti.pdf");
..code..
ora, ogni tanto mi da questa eccezione (il programma funzia lo stesso, ma vorrei toglierla),
come posso fare??

codice:
GRAVE: Servlet.service() for servlet jsp threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
	at org.apache.catalina.connector.Response.getWriter(Response.java:604)
	at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:198)
	at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112)
	at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:125)
	at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:118)
	at org.apache.jasper.runtime.JspWriterImpl.flush(JspWriterImpl.java:173)
	at org.apache.struts.tiles.taglib.InsertTag$InsertHandler.doEndTag(InsertTag.java:893)
	at org.apache.struts.tiles.taglib.InsertTag.doEndTag(InsertTag.java:465)
	at org.apache.jsp.layout.Layout_jsp._jspx_meth_tiles_005finsert_005f0(Layout_jsp.java:125)
	at org.apache.jsp.layout.Layout_jsp._jspService(Layout_jsp.java:76)
	at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
	at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
	at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:654)
	at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:557)
	at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:481)
	at org.apache.struts.action.RequestProcessor.doInclude(RequestProcessor.java:1105)
	at org.apache.struts.tiles.TilesRequestProcessor.doForward(TilesRequestProcessor.java:292)
	at org.apache.struts.tiles.TilesRequestProcessor.processTilesDefinition(TilesRequestProcessor.java:271)
	at org.apache.struts.tiles.TilesRequestProcessor.processForwardConfig(TilesRequestProcessor.java:332)
	at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:232)
	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:710)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:654)
	at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:445)
	at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:379)
	at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:292)
	at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1078)
	at org.apache.struts.tiles.TilesRequestProcessor.doForward(TilesRequestProcessor.java:295)
	at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:396)
	at org.apache.struts.tiles.TilesRequestProcessor.processForwardConfig(TilesRequestProcessor.java:347)
	at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:232)
	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:710)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:525)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:263)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:584)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
	at java.lang.Thread.run(Thread.java:619)
grazie ciao.