render Pdf in IE 7

[p792]

For some reasons, the application can render pdf in firefox but not in IE 7. I hope someone can tell me what I did wrong.

my url: http://<localhost>/<applicationName>/listDoc/viewpdf.htm?filename=test.pdf

@RequestMapping(value="/listDoc/viewPdf",method=RequestMethod.GET)
	public @ResponseBody String streamPdf(HttpServletRequest request,
			HttpServletResponse response,			
			@RequestParam(value = "fileName", required = false) String fileName,
			SessionStatus status, ModelMap modelMap) throws Exception{
		ServletOutputStream outstream = response.getOutputStream();
		try{			 
			logger.debug("Prepare to view pdf");
			File tempDir = WebUtils.getTempDir(getServletContext());
			String filePath = tempDir.getCanonicalPath()+"/"+fileName;			
			File generatePdfFile = new File(filePath);
			if ((generatePdfFile.exists() && (generatePdfFile.canRead()))){				
				FileInputStream fileInputStream = new FileInputStream(generatePdfFile);
				response.setContentType("application/pdf");				
				response.setContentLength((int)generatePdfFile.length());
			        response.setHeader("Content-Disposition","inline; filename=test.pdf");
				int readBytes=0;
				while((readBytes = fileInputStream.read()) != -1) {  
					outstream.write(readBytes);					
				}				
				fileInputStream.close();				
				outstream.flush();
				outstream.close();				
				
			} else {
				throw new Exception("Either document doesn't exist or can not be read");
			}
			
			
		}catch(Exception e){
			e.printStackTrace();
			logger.error(e.getMessage(),e.fillInStackTrace());
			throw new Exception ("Unable to stream pdf.  Please contact your administrator");
		}finally{
			outstream.close();
			outstream.flush();
		}	
		
	}

My web.xml

<servlet>
		<servlet-name>sampleapplication</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<init-param>
			<param-name>contextConfigLocation</param-name>
			<param-value>
					classpath:sampleapplication-web.xml								
				</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>sampleapplication</servlet-name>
		<url-pattern>*.htm</url-pattern>
	</servlet-mapping>

Thank for reading...