JasperReport erro de java.io.FileNotFoundException

public class RelatorioAluno {
	private Integer matricula;
	private String nome;
	private String curso;
	private Double nota1;
	private Double nota2; 
	private static List <Aluno> listAluno;   
	       
	       
	       
	     @SuppressWarnings("unchecked")
		public void execute(ServletContext sc, HttpServletRequest request, HttpServletResponse response) {          
	         try {  
	             List <RelatorioAluno> listRelAluno = new ArrayList<RelatorioAluno>();  
	             AlunoDao dao = new AlunoDao();
	             listAluno = dao.getAllAlunos();   
	               
	             for(int i=0; i < listAluno.size(); i++){  
	                 RelatorioAluno relAluno = new RelatorioAluno();  
	                 relAluno.setMatricula((listAluno.get(i).getMatricula()));  
	                 relAluno.setNome((listAluno.get(i).getNome()));  
	                 relAluno.setCurso((listAluno.get(i).getCurso()));  
	                 relAluno.setNota1((listAluno.get(i).getNota1()));  
	                 relAluno.setNota2((listAluno.get(i).getNota2()));
	                 
	                 listRelAluno.add(relAluno);  
	             }  
	               
	             JRDataSource jrds = new JRBeanCollectionDataSource(listRelAluno);  
	                           
	             // parametros do relatorio  
	             HashMap parameters = new HashMap();  
	             // lendo arquivo jasper  
	             File reportFile = new File(sc.getRealPath("/rel"));  
	             
	             byte[] bytes = null;  
	             try {                  
	                 bytes = JasperRunManager.runReportToPdf(reportFile+"/aluno.jasper", parameters, jrds);  
	                 //JasperPrint print = JasperFillManager.fillReport(reportFile.getPath(), parameters, jrds);  
	               
	                 //bytes = JasperExportManager.exportReportToPdf(print);  
	                 //JasperViewer.viewReport( reportFile.getName() + ".pdf", false );  ]
	                 JasperViewer.viewReport(reportFile + "/aluno.jrprint", false);
	             } catch (Exception e) {                  
	                 e.printStackTrace();  
	                 return;  
	             }                                
	             //  
	             if (bytes != null && bytes.length > 0) {  
	                 response.setContentType("application/pdf");  
	                 response.setContentLength(bytes.length);  
	                 ServletOutputStream ouputStream = response.getOutputStream();  
	                 ouputStream.write(bytes, 0, bytes.length);  
	                 ouputStream.flush();  
	                 ouputStream.close();  
	             }  
	         } catch (Exception e) {  
	             e.printStackTrace();  
	         }  
	     }