I am looking to build a Restful application using Spring Boot to convert CSV items to JSON objects and I want to understand the best approach to do it.

If CSV or CSV items can be passed through getMapping() method and then converted to JSON.

CodePudding user response：

The best approach would be using POST Mapping, GET Mapping is not considered a good approach. Also I am using jackson library to read csv file and conversion as it make lot of things easier. Hope this generic code will help.

Controller

@PostMapping("/api/file-upload")
public ResponseEntity<String> uploadSingleFile (@RequestParam("csvFile") MultipartFile csvFile) {
  try{        
    serviceClass.convertCsvToJson(csvFile);
    return ResponseEntity.status(HttpStatus.OK).body("File uploaded");
  }catch(Exception e){
     return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body("File upload failed");
  }         
}

Service class method

public void convertCsvToJson(MultipartFile csvFile){
CsvSchema csvSchema = CsvSchema.emptySchema().withHeader();
CsvMapper csvMapper = new CsvMapper();
try {
        List<Map<?, ?>> list;
        try (MappingIterator<Map<?, ?>> mappingIterator = csvMapper.reader()
                .forType(Map.class)
                .with(csvSchema)
                .readValues(csvFile)) {
            list = mappingIterator.readAll();
        }

        ObjectMapper objectMapper = new ObjectMapper();
        // You can also map csv content to you own pojo
        String jsonPretty = objectMapper.writerWithDefaultPrettyPrinter()
                .writeValueAsString(list);
                
        // Do something with json string        
    } catch (IOException e) {
        e.printStackTrace();
        throw e;
    }
}