使用 CSV 文件将对象添加到 arrayList，但对象的值返回 null

Question

I'm trying to use a CSV file to create a list of employee objects, but I'm currently getting null for every value. The values being: username, firstname, lastname, email, gender, race, id, and ssn. I can read in the CSV file and parse it fine, but when I try to populate the list with the objects, It fills them but every value is still null. The main method:

public static void main(String[] args) {
    String csvFile = "employee_data.csv";
    BufferedReader br = null;
    String line = "";
    String cvsSplitBy = ",";
    List<Entry> People = new ArrayList<>();
    try {
        br = new BufferedReader(new FileReader(csvFile));
        while ((line = br.readLine()) != null) {
            // use comma as separator
            String[] Labels = line.split(cvsSplitBy);                 
            Entry entry = new Entry(Labels[0], Labels[1], Labels[2], Labels[3], Labels[4], Labels[5], Labels[6], Labels[7]);
            People.add(entry);
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if (br != null) {
            try {
                br.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    System.out.print(People);
}

The Entry class:

public class Entry {
    private String Username, Firstname, Lastname, Email, Gender, Race, ID, SSN;
    public Entry(String Username, String Firstname, String Lastname, String Email, String Gender, String Race, String ID, String SSN) {
        this.Username=null;
        this.Firstname=null;
        this.Lastname=null;
        this.Email=null;
        this.Gender=null;
        this.Race=null;
        this.ID=null;
        this.SSN=null;
    }
    @Override
    public String toString() {
        return ("Username:"+this.Username);
    }
}

I'm not sure why the Entry objects are being properly added to the List, but the values from the Labels array is not being transferred, so username, firstname, etc are all being labeled null and I cant figure out why

Answer 1

I think the constructor on your Entry class needs to assign the parameters to the fields in your class. How about the following:

public class Entry {

    private String Username, Firstname, Lastname, Email, Gender, Race, ID, SSN;

    public Entry(String Username, String Firstname, String Lastname, String Email, String Gender, String Race, String ID, String SSN) {
        this.Username = Username;
        this.Firstname = Firstname;
        this.Lastname = Lastname;
        this.Email = Email;
        this.Gender = Gender;
        this.Race = Race;
        this.ID = ID;
        this.SSN = SSN;
    }

    @Override
    public String toString() {
        return ("Username:" + this.Username);
    }
}