How To Parse OffsetDateTime From Csv File

Question

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

Answer 1

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;