problem with getOutputStream() has already been called for this response

[Theeranit Pongtongmuang]

I got java.lang.IllegalStateException and don't know how to solve this problem.

public ActionForward exportToBtmu(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {


byte[] buf = new byte[1024];

try {
// Create the ZIP file


response.setContentType("application/zip");
response.setHeader("Content-Disposition","attachment;filename=export.zip;");


ZipOutputStream out = new ZipOutputStream(response.getOutputStream());

// Compress the files

FileInputStream in = new FileInputStream(txt1.txt);

// Add ZIP entry to output stream. only file Name not full path
out.putNextEntry(new ZipEntry(txt1.txt));

// Transfer bytes from the file to the ZIP file
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}

// Complete the entry
out.closeEntry();
in.close();

// delete file after complete add to zip
fileToZip.delete();

out.flush();
// Complete the ZIP file
out.close();

} catch (IOException e) {
e.printStackTrace();

}



return mapping.findForward(FORWARD_view);

}


and this is exception message that I got



java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:610)
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.taglib.tiles.InsertTag$InsertHandler.doEndTag(InsertTag.java:889)
at org.apache.struts.taglib.tiles.InsertTag.doEndTag(InsertTag.java:462)
at org.apache.jsp.pages.template_jsp._jspx_meth_tiles_005finsert_005f0(template_jsp.java:251)
at org.apache.jsp.pages.template_jsp._jspx_meth_logic_005fnotEmpty_005f0(template_jsp.java:223)
at org.apache.jsp.pages.template_jsp._jspx_meth_html_005fhtml_005f0(template_jsp.java:158)
at org.apache.jsp.pages.template_jsp._jspService(template_jsp.java:84)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
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:630)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:535)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:472)
at org.apache.struts.action.RequestProcessor.doInclude(RequestProcessor.java:1116)
at org.apache.struts.tiles.TilesRequestProcessor.doForward(TilesRequestProcessor.java:260)
at org.apache.struts.tiles.TilesRequestProcessor.processTilesDefinition(TilesRequestProcessor.java:239)
at org.apache.struts.tiles.TilesRequestProcessor.processForwardConfig(TilesRequestProcessor.java:302)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:241)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
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:191)
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:286)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Unknown Source)
Aug 20, 2009 6:33:06 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet action threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:610)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:198)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112)
at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:125)
at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:118)
at org.apache.jasper.runtime.JspWriterImpl.flush(JspWriterImpl.java:173)
at org.apache.struts.taglib.tiles.InsertTag$InsertHandler.doEndTag(InsertTag.java:889)
at org.apache.struts.taglib.tiles.InsertTag.doEndTag(InsertTag.java:462)
at org.apache.jsp.pages.template_jsp._jspx_meth_tiles_005finsert_005f0(template_jsp.java:251)
at org.apache.jsp.pages.template_jsp._jspx_meth_logic_005fnotEmpty_005f0(template_jsp.java:223)
at org.apache.jsp.pages.template_jsp._jspx_meth_html_005fhtml_005f0(template_jsp.java:158)
at org.apache.jsp.pages.template_jsp._jspService(template_jsp.java:84)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
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:630)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:535)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:472)
at org.apache.struts.action.RequestProcessor.doInclude(RequestProcessor.java:1116)
at org.apache.struts.tiles.TilesRequestProcessor.doForward(TilesRequestProcessor.java:260)
at org.apache.struts.tiles.TilesRequestProcessor.processTilesDefinition(TilesRequestProcessor.java:239)
at org.apache.struts.tiles.TilesRequestProcessor.processForwardConfig(TilesRequestProcessor.java:302)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:241)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
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:191)
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:286)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Unknown Source)

I 'm waiting for your good suggestion.

Amm

[Ankit Garg]

You are writing a custom response to the client, so some output is sent to the client. Then when you return an ActionForward from your method, you get the exception. You can't write something to the client and then forward a request. You should return null from your action method. The basic use of your action seems to me is to return a zip file. Then do you also want to display a page with this??

[Ankit Garg]

Also please Use Code Tags when you post a source code to make your program readable...

[Theeranit Pongtongmuang]

Thank you for your reply.

However, I want the page refresh after download zip file completely.

So, I try to return view(mapping, exportForm, request, response);
to get the page refresh and got this problem.

Please give me some suggestion.