Salve a tutti,
sto cercando di capire perchè il server mi tira fuori la seguente eccezione: SRVE0199E: OutputStream already obtained
In sostanza credo di averlo già capito, ma non so come raggirare l'ostacolo.

Dalla JSP invoco un metodo della Action in cui riapro lo stream " outZip= new ZipOutputStream(httpResponse.getOutputStream());" quando il metodo termina ritorna sulla stessa pagina aggiornandola, pero' il server si accorge che nella action lo stream è stato già aperto per cui lancia l'eccezione in esame.
Per ovviare a tale problema bisogna dichiarare il metodo nella action di tipo void, ma questo rappresenterebbe nel mio caso solo una soluzione non ottimale , perchè io vorrei che la pagina si aggiornasse.
Qualcuno ha già risolto un problema simile?

codice:
10:18:23,656 ERROR ClosingUIBean:38 - Could not open template
java.lang.IllegalStateException: SRVE0199E: OutputStream already obtained
	at com.ibm.ws.webcontainer.srt.SRTServletResponse.getWriter(SRTServletResponse.java:531)
	at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:187)
	at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:175)
	at org.apache.jasper.runtime.JspWriterImpl.write(JspWriterImpl.java:343)
	at java.io.PrintWriter.write(PrintWriter.java:375)
	at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:176)
	at org.apache.jasper.runtime.JspWriterImpl.write(JspWriterImpl.java:359)
	at org.apache.struts2.components.template.FreemarkerTemplateEngine$1.write(FreemarkerTemplateEngine.java:143)
	at java.io.Writer.write(Writer.java:171)
	at java.io.Writer.write(Writer.java:147)
	at freemarker.core.DollarVariable.accept(DollarVariable.java:76)
	at freemarker.core.Environment.visit(Environment.java:210)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:210)
	at freemarker.core.ConditionalBlock.accept(ConditionalBlock.java:79)
	at freemarker.core.Environment.visit(Environment.java:210)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:210)
	at freemarker.core.IfBlock.accept(IfBlock.java:82)
	at freemarker.core.Environment.visit(Environment.java:210)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:210)
	at freemarker.core.Environment.include(Environment.java:1483)
	at freemarker.core.Include.accept(Include.java:169)
	at freemarker.core.Environment.visit(Environment.java:210)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:210)
	at freemarker.core.Environment.process(Environment.java:190)
	at freemarker.template.Template.process(Template.java:237)
	at org.apache.struts2.components.template.FreemarkerTemplateEngine.renderTemplate(FreemarkerTemplateEngine.java:157)
	at org.apache.struts2.components.UIBean.mergeTemplate(UIBean.java:559)
	at org.apache.struts2.components.ClosingUIBean.start(ClosingUIBean.java:59)
	at org.apache.struts2.views.jsp.ComponentTagSupport.doStartTag(ComponentTagSupport.java:53)
	at com.ibm._jsp._pagamentoLottiPage._jspx_meth_s_submit_1(_pagamentoLottiPage.java:273)
	at com.ibm._jsp._pagamentoLottiPage._jspx_meth_s_if_1(_pagamentoLottiPage.java:306)
	at com.ibm._jsp._pagamentoLottiPage._jspx_meth_s_form_0(_pagamentoLottiPage.java:344)
	at com.ibm._jsp._pagamentoLottiPage._jspService(_pagamentoLottiPage.java:90)
	at com.ibm.ws.jsp.runtime.HttpJspBase.service(HttpJspBase.java:85)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
	at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:966)
	at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:907)
	at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:118)
	at com.ibm.ws.webcontainer.filter.WebAppFilterChain._doFilter(WebAppFilterChain.java:87)
	at com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:701)
	at com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:646)
	at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:475)
Grazie 1000