JAVA

api to accept a csv file spring boot

package com.bezkoder.spring.files.csv.controller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
import com.bezkoder.spring.files.csv.service.CSVService;
import com.bezkoder.spring.files.csv.helper.CSVHelper;
import com.bezkoder.spring.files.csv.message.ResponseMessage;
import com.bezkoder.spring.files.csv.model.Tutorial;
@CrossOrigin("http://localhost:8081")
@Controller
@RequestMapping("/api/csv")
public class CSVController {
  @Autowired
  CSVService fileService;
  @PostMapping("/upload")
  public ResponseEntity<ResponseMessage> uploadFile(@RequestParam("file") MultipartFile file) {
    String message = "";
    if (CSVHelper.hasCSVFormat(file)) {
      try {
        fileService.save(file);
        message = "Uploaded the file successfully: " + file.getOriginalFilename();
        return ResponseEntity.status(HttpStatus.OK).body(new ResponseMessage(message));
      } catch (Exception e) {
        message = "Could not upload the file: " + file.getOriginalFilename() + "!";
        return ResponseEntity.status(HttpStatus.EXPECTATION_FAILED).body(new ResponseMessage(message));
      }
    }
    message = "Please upload a csv file!";
    return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(new ResponseMessage(message));
  }
  @GetMapping("/tutorials")
  public ResponseEntity<List<Tutorial>> getAllTutorials() {
    try {
      List<Tutorial> tutorials = fileService.getAllTutorials();
      if (tutorials.isEmpty()) {
        return new ResponseEntity<>(HttpStatus.NO_CONTENT);
      }
      return new ResponseEntity<>(tutorials, HttpStatus.OK);
    } catch (Exception e) {
      return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
    }
  }
}