Using getters and setters with ArrayLists in java

Question

I'm trying to read a csv and storing the records in an ArrayList. Since I know the no. of records in the csv file I'm specifying the size i.e. 600 when creating the object. I want the program to be able to read files of unknown no. of records. How do I make it dynamic.

Here's the working code for the file with 600 records.

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.io.*;


public class BankRecords extends Client{
//Create objects for processing data
//private static int count;
static BankRecords[] obj=new BankRecords[600];
static List<List<String>> array = new ArrayList<List<String>>();
@Override
void readData() {
    // TODO Auto-generated method stub
    String line=" ";
    //int i=0;

    //try with resources statement
    try(BufferedReader br = new BufferedReader(new FileReader("bank-Detail.csv"))){

        while((line=br.readLine()) != null) //read from file
        {   
            array.add(Arrays.asList(line.split(",")));
            //check data
            //count++;
            //System.out.println(array.get(i++));
        }

    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    processData();
}
@Override
void processData() {
    // TODO Auto-generated method stub

    int idx=0;
    for(List<String> bankData: array)
    {

        obj[idx]= new BankRecords();
        obj[idx].setId(bankData.get(0));
        obj[idx].setAge(Integer.parseInt(bankData.get(1)));
        obj[idx].setSex(bankData.get(2));
        obj[idx].setRegion(bankData.get(3));
        obj[idx].setIncome(Double.parseDouble(bankData.get(4)));
        obj[idx].setMarried(bankData.get(5));
        obj[idx].setChild(Integer.parseInt(bankData.get(6)));
        obj[idx].setCar(bankData.get(7));
        obj[idx].setSact(bankData.get(8));
        obj[idx].setCact(bankData.get(9));
        obj[idx].setMort(bankData.get(10));
        obj[idx].setPep(bankData.get(11));


        idx++;

        //System.out.println(obj[idx].getId());
        }

    printData();
}





@Override
void printData() {

    //Printing First 25 ID, age, sex, region, income and mortgage
    System.out.println("ID\t\tAGE\t\tSEX\t\tREGION\t\tINCOME\t\tMORTGAGE\n");
    for(int i=0;i<25;i++){

        String s=String.format("%s\t\t%s\t\t%s\t\t%-10s\t%8.2f\t%2s", obj[i].getId(),obj[i].getAge(),obj[i].getSex(),obj[i].getRegion(),obj[i].getIncome(),obj[i].getMort());
        System.out.println(s);
    }
}
public String getId() {
    return id;
}




public void setId(String id) {
    this.id = id;
}




public int getAge() {
    return age;
}




public void setAge(int age) {
    this.age = age;
}




public String getSex() {
    return sex;
}




public void setSex(String sex) {
    this.sex = sex;
}




public String getRegion() {
    return region;
}




public void setRegion(String region) {
    this.region = region;
}




public double getIncome() {
    return income;
}




public void setIncome(double income) {
    this.income = income;
}




public String isMarried() {
    return married;
}




public void setMarried(String married) {
    this.married = married;
}




public int getChild() {
    return child;
}




public void setChild(int child) {
    this.child = child;
}




public String getCar() {
    return car;
}




public void setCar(String car) {
    this.car = car;
}




public String getSact() {
    return sact;
}




public void setSact(String sact) {
    this.sact = sact;
}




public String getCact() {
    return cact;
}




public void setCact(String cact) {
    this.cact = cact;
}




public String getMort() {
    return mort;
}




public void setMort(String mort) {
    this.mort = mort;
}




public String getPep() {
    return pep;
}




public void setPep(String pep) {
    this.pep = pep;
}




public static void main(String[] args) {
    // TODO Auto-generated method stub
    BankRecords bnk= new BankRecords();
    bnk.readData();
}

}

Answer 1

ArrayList can the elements dynamically, so it is not required to know the size in advance.

However, for the BankRecords array, do not initialize it with 600 initially. Instead do something like this:

static BankRecords[] obj = null;
static List<List<String>> array = new ArrayList<List<String>>();
void processData() {
    // TODO Auto-generated method stub
    obj=new BankRecords[array.size()];
    // TODO do your work here 
}