getOutputStream() has already been called for this response

[srinivasmallabathula]

try {

			reportFile = request.getRealPath("/")+"WEB-INF/Documents/TestCases/ScenarioDetails.jrxml";
			 
			JasperDesign jasperDesign = JRXmlLoader.load(reportFile); 
			JasperReport report = JasperCompileManager.compileReport(jasperDesign);
			conn = dataSource.getConnection();
			JasperPrint jasperPrint = JasperFillManager.fillReport(report,map, conn);
			conn.close();

			ByteArrayOutputStream baos = new ByteArrayOutputStream();

			
			response.setContentType("application/pdf");
			response.setHeader("Content-Disposition"," attachment; filename="+OfficeName+".pdf\"");
			export(jasperPrint,baos);
			writeReportToResponseStream(response,baos);
		}catch(Exception e) {
			e.printStackTrace();
		}
			
		
		 return new ModelAndView("top","model",model);

private void writeReportToResponseStream(HttpServletResponse response,ByteArrayOutputStream baos) {		
		System.out.println("Writing report to the stream");
		ServletOutputStream outputStream = null;
		try {
			// Retrieve the output stream
			outputStream = response.getOutputStream();
			// Write to the output stream
			baos.writeTo(outputStream);
			// Flush the stream
			outputStream.flush();
			outputStream.close();

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

public void export(JasperPrint jasperPrint, ByteArrayOutputStream baos)  throws JRException {
		
		JRPdfExporter exporter=new JRPdfExporter();
		exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
        exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, baos);
        exporter.exportReport();
}

For generating PDF reports I have used above code(jasper reports).Reports are generated properly but in server console it shows following exception.

ERROR [[jsp]] 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(R esponse.java:604)
at org.apache.catalina.connector.ResponseFacade.getWr iter(ResponseFacade.java:198)
at javax.servlet.ServletResponseWrapper.getWriter(Ser vletResponseWrapper.java:112)
at org.apache.jasper.runtime.JspWriterImpl.initOut(Js pWriterImpl.java:125)
at org.apache.jasper.runtime.JspWriterImpl.flushBuffe r(JspWriterImpl.java:118)
at org.apache.jasper.runtime.PageContextImpl.release( PageContextImpl.java:178)
at org.apache.jasper.runtime.JspFactoryImpl.internalR eleasePageContext(JspFactoryImpl.java:117)
at org.apache.jasper.runtime.JspFactoryImpl.releasePa geContext(JspFactoryImpl.java:76)


how to fix this problem..Thanks in advance

[Tolls]

writeReportToResponseStream(response,baos); 
...
return new ModelAndView("top","model",model);

You've written to the output stream, but you then pass a model and view back up to Spring, presumably referencing a JSP page.
Spring tells Tomcat to forward to that JSP, and so Tomcat attempts to write it out....which it can't do as you've already written to the response stream.

So the solution is don't return the ModelAndView. Return 'null', which should tell Spring not to bother forwarding anywhere.

[zed420]

This has solved my issue too, thank you