javaspring-bootopencsvoffsetdatetime

How To Parse OffsetDateTime From Csv File


I am trying to use opencsv to parse a csv file like this:

2020-09-18 06:50:00.000000

I am trying to add the parsed data following this tutorial: https://attacomsian.com/blog/spring-boot-upload-parse-csv-file. This is my model:

public class MyIndPrd implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    @CsvBindByName
    private String service;
    @CsvBindByName
    private OffsetDateTime time;
    @CsvBindByName
    private Long nbAppels;
    @CsvBindByName
    private Double tempsDeReponseMoyenMillisecondes;
    @CsvBindByName
    private Long volume;
    @CsvBindByName
    private Double tempsDeReponseMoyenSecondes;
}

I try to parse the offsetDateTime

by doing :

OffsetDateTime odt = OffsetDateTime.parse (myIndPrds.get (i) .getTime ());

before recording it

but it doesn't seem like you want to do it

@PostMapping("/upload-csv-file")
    public String uplaodCSVFile(@RequestParam("file") MultipartFile file, Model model){
        if (file.isEmpty()){
            model.addAttribute("message", "Veuillez selectionner un fichier csv à importer.");
            model.addAttribute("status", false);
        }else try (Reader reader = new BufferedReader(new InputStreamReader(file.getInputStream()))) {

            // create csv bean reader
            CsvToBean<MyIndPrd> csvToBean = new CsvToBeanBuilder(reader)
                    .withType(MyIndPrd.class)
                    .withSeparator(';')
                    .withIgnoreLeadingWhiteSpace(true)
                    .build();

            // convert CsvToBean object
            List<MyIndPrd> myIndPrds = csvToBean.parse();
            for (int i = 0;i<myIndPrds.size();i++){

                OffsetDateTime odt = OffsetDateTime.parse(myIndPrds.get(i).getTime());

                MyIndPrd ind = new MyIndPrd();
                ind.setService(myIndPrds.get(i).getService());
                ind.setTime(odt);
                ind.setNbAppels(Long.valueOf(myIndPrds.get(i).getNbAppels()));
                ind.setVolume(Long.valueOf(myIndPrds.get(i).getVolume()));
                ind.setTempsDeReponseMoyenMillisecondes(Double.valueOf(myIndPrds.get(i).getTempsDeReponseMoyenMillisecondes()));
                ind.setTempsDeReponseMoyenSecondes(Double.valueOf(myIndPrds.get(i).getTempsDeReponseMoyenSecondes()));
                iMyIndPrdService.saveMyData(ind);
            }


            model.addAttribute("myIndProdCsv", myIndPrds);
            model.addAttribute("status", true);


        } catch (Exception ex) {
            model.addAttribute("message", "An error occurred while processing the CSV file.");
            model.addAttribute("status", false);
        }
        return "mon-dasboard";
    }

Thanks for your help


Solution

  • Your date-time string (e.g. 2020-09-18 06:50:00.000000 as you have mentioned in the question) in the CSV does not have timezone-offset and therefore the most appropriate type to parse it into would be LocalDateTime.

    You can define a converter class to convert the date-time string from the CSV into LocalDateTime.

    public class LocalDateTimeConverter extends AbstractBeanField {
        @Override
        protected Object convert(String s) throws CsvDataTypeMismatchException, CsvConstraintViolationException {
            DateTimeFormatter dtf = DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss.n");
            LocalDateTime ldt = LocalDateTime.parse(strDate, dtf);
            return ldt;
        }
    }
    

    and then you can annotate the field as

    @CsvBindByName(converter = LocalDateTimeConverter.class)
    private LocalDateTime time;
    

    However, if you still want to parse your date-time string into OffsetDateTime, here is how you can do it:

    public class OffsetDateTimeConverter extends AbstractBeanField {
        @Override
        protected Object convert(String s) throws CsvDataTypeMismatchException, CsvConstraintViolationException {
            DateTimeFormatter dtf = DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss.n").withZone(ZoneId.systemDefault());
            ZonedDateTime zdt = ZonedDateTime.parse(strDate, dtf);
            OffsetDateTime odt = zdt.toOffsetDateTime();
            return odt
        }
    }
    

    and then you can annotate the field as

    @CsvBindByName(converter = OffsetDateTimeConverter.class)
    private OffsetDateTime time;
    

    A quick demo of how this parsing works:

    import java.time.OffsetDateTime;
    import java.time.ZoneId;
    import java.time.ZonedDateTime;
    import java.time.format.DateTimeFormatter;
    
    public class Main {
        public static void main(String[] args) {
            String strDate = "2020-09-18 06:50:00.000000";
            DateTimeFormatter dtf = DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss.n").withZone(ZoneId.systemDefault());
            ZonedDateTime zdt = ZonedDateTime.parse(strDate, dtf);
            OffsetDateTime odt = zdt.toOffsetDateTime();
            System.out.println(zdt);
            System.out.println(odt);
        }
    }
    

    If you are using OpenCSV 5

    You do not need to define a converter class. You can simply do it as

    @CsvDate(value = "uuuu-MM-dd HH:mm:ss.n")
    @CsvBindByName
    private LocalDateTime time;