Data pass dispatcherServlet

Question

I am trying to perform data export from Log to Excel only it is presenting me the following error:

2019-03-18 10:16:16.022 ERROR 252 --- [nio-8080-exec-4] o.a.c.c.C.[.[.[.[dispatcherServlet]      : Servlet.service() for servlet [dispatcherServlet] in context with path [/mv-fatur] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause

The implementation is being done as follows:

Logacessoutil.java

@Override
@SuppressWarnings("unchecked")
public List<LogAcessoDTO> getLogAcessoExcel(String cdCliente) {

    LocalDateTime agora = LocalDateTime.now();
    DateTimeFormatter formatterData = DateTimeFormatter.ofPattern("dd/MM/uuuu");
    String dataFormatada = formatterData.format(agora);

    StringBuilder sql = new StringBuilder();
    sql.append("select * from cli");

    List<LogAcessoDTO> returnQuery = em.createNativeQuery(sql.toString(), "LogAcessoDTOMapping").getResultList();

    return (List<LogAcessoDTO>) returnQuery;
}

Globalcontroller.java

@Autowired
private LogAcessoUtil logAcessoUtil;

@Autowired
private ExportFileService<LogAcessoDTO> exportFileServiceDetalhe;

@GetMapping("/getlogacesso/excel")
    public ResponseEntity<List<LogAcessoDTO>> getLogAcessoExcel(@RequestParam String cdCliente, HttpServletResponse response) {
        try {
            List<LogAcessoDTO> dtos = logAcessoUtil.getLogAcessoExcel(cdCliente);

            exportFileServiceDetalhe.exportExcelFile(dtos, response, "LogAcesso", "", "Cod. Cliente: " + cdCliente.toString());

            return new ResponseEntity<>(HttpStatus.OK);
        } catch (NoSuchMethodException | SecurityException | IllegalAccessException | IllegalArgumentException
            | InvocationTargetException | IOException ex) {
            log.error(ex.toString());
            return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }

Answer 1

The data you provided is not enough to be sure about the issue, but the exception launched (NullPointerException) indicates that a method is being invoked (called) by a null object or attribute.

Make sure you have (new NomeDaClasse()) or noted (with @Autowired, for example) variables/attributes logAcessoUtil and exportFileServiceDetalhe correctly.

The parameters cdCliente and response should not be null either.