java

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;
import java.util.HashMap;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class CSVReader<Stringbuilder> {
    BufferedReader reader;
    String delimiter;
    boolean hasHeader;
    String[]current;
    // nazwy kolumn w takiej kolejności, jak w pliku
    List<String> columnLabels = new ArrayList<>();
    // odwzorowanie: nazwa kolumny -> numer kolumny
    Map<String,Integer> columnLabelsToInt = new HashMap<>();

    /**
     *
     * @param filename - nazwa pliku
     * @param delimiter - separator pól
     * @param hasHeader - czy plik ma wiersz nagłówkowy
     */

    public CSVReader(String filename,String delimiter, boolean hasHeader) throws IOException {
        reader = new BufferedReader(new FileReader(filename));
        this.delimiter = delimiter;
        this.hasHeader = hasHeader;
        if(hasHeader)parseHeader();
    }

    public CSVReader(String filename, String delimiter) throws IOException {
        this(filename, delimiter, false);
    }

    public CSVReader(String filename) throws IOException {
        this(filename, ",", false);
    }

    public CSVReader(Reader reader, String delimiter, boolean hasHeader) throws IOException {
        this.reader = new BufferedReader(reader);
        this.delimiter = delimiter;
        this.hasHeader = hasHeader;
        if(hasHeader)parseHeader();
    }

    void parseHeader() throws IOException {
        // wczytaj wiersz
        String line = reader.readLine();
        if (line == null) {
            return;
        }

        // podziel na pola
        String[] header = line.split(delimiter);
        // przetwarzaj dane w wierszu
        for (int i = 0; i < header.length; i++) {
            columnLabels.add(header[i]);
            columnLabelsToInt.put(header[i], i);
        }
    }

    boolean next() throws IOException{
        String line = reader.readLine();
        if (line == null) {
            return false;
        }
        this.current = line.split(delimiter);
        return true;
    }

    List<String> getColumnLabels() {
        return columnLabels;
    }

    int getRecordLength() {
        return current.length;
    }

    boolean isMissing(int columnIndex){
        if (current[columnIndex] == "") return true;
        return false;
    }

    boolean isMissing(String columnLabel){
        if (current[columnLabelsToInt.get(columnLabel)] == "") return true;
        return false;
    }

    String get(int columnIndex){
        return current[columnIndex];
    }

    String get(String columnLabel){
        return current[columnLabelsToInt.get(columnLabel);
    }






    public static void main(String[] args) throws IOException {
        CSVReader reader = new CSVReader("with-header.csv",",",true);

        List<String> labels;
        labels = reader.getColumnLabels();
        for (String l : labels) System.out.println(l);

        while(reader.next()){
            //System.out.printf(Locale.Us,"%d %s %d",id, name, fare);
        }
    }
}