read data from MultipartFile which has csv uploaded from browser

Question

May be I am doing it worng by using MultipartFile upload feature.

I have to read data from csv file which will be chosen by the client through the browser. I used Mu

Answer 1

I used a buffer to read line by line and get from multipart the inputstream. Maybe is more code, but I find helpful read text file by lines.

BufferedReader br;
List<String> result = new ArrayList<>();
try {

     String line;
     InputStream is = multipart.getInputStream();
     br = new BufferedReader(new InputStreamReader(is));
     while ((line = br.readLine()) != null) {
          result.add(line);
     }

  } catch (IOException e) {
    System.err.println(e.getMessage());       
  }

Answer 2

The best solution that I found was

@PostMapping(value="/csv")
public ResponseEntity<Void> processUpload(@RequestParam MultipartFile file) {

BufferedReader fileReader = new BufferedReader(new 
InputStreamReader(file.getInputStream(), "UTF-8"));
CSVParser csvParser = new CSVParser(fileReader, CSVFormat.DEFAULT);

Iterable<CSVRecord> csvRecords = csvParser.getRecords();

for (CSVRecord csvRecord : csvRecords) {
    System.out.println(csvRecord);
}
...

This is an adaptative solution from https://bezkoder.com/spring-boot-upload-csv-file/

Answer 3

I figured out a workaround. I converted the file to bytes and then converted the bytes to String. From String I applied string.split() to get what I wanted out of the file.

    @RequestMapping(value = "/uploadFile", method = RequestMethod.POST)
public String uploadFileHandler(@RequestParam("file") MultipartFile file) {
    if (!file.isEmpty()) {
        try {
            byte[] bytes = file.getBytes();
            String completeData = new String(bytes);
            String[] rows = completeData.split("#");
            String[] columns = rows[0].split(",");