Notes

import java.io.*;
import java.util.*;

public class PFPUser { // usernameID,IDvirtualBank
private VirtualBank virtualBank = null;
private String usernameID;

public PFPUser(String usernameID) {
this.usernameID = usernameID;
this.virtualBank = this.findVirtualBank(this.usernameID);
}

private VirtualBank findVirtualBank(String usernameID) {
VirtualBank bank = null;
BufferedReader reader;
String data[];
try {
reader = new BufferedReader(new FileReader("PFPUser.txt"));
String line;
while ((line = reader.readLine()) != null) {
data = line.split(",");
if (data[0].equals(usernameID)) {
if (!data[1].equals("null")) {
bank = new VirtualBank(Integer.parseInt(data[1]));
}
}
}
} catch (NumberFormatException | IOException e) {
e.printStackTrace();
}
return bank;
}
public VirtualBank getVirtualBank() {
return this.virtualBank;
}

public void purchase(double amount, PFPUser user) {
if ((this.virtualBank != null && user.getVirtualBank() != null) == true) {
this.virtualBank.transfer(amount, user.getVirtualBank());
}
else {
System.out.println("Virtual Bank account couldn't found.");
}
}
public void defineNewVirtualBank(String ID, String virtualBankUsername, String virtualBankPassword) {
if (virtualBankUsername == VirtualBank.searchByID(ID)[1] && virtualBankPassword == VirtualBank.searchByID(ID)[2] && VirtualBank.searchByID(ID) != null) {
File file = new File("PFPUser.txt");
File tempFile = new File("temp.txt");
BufferedWriter writer = null;
BufferedReader reader = null;
String line;
try {
reader = new BufferedReader(new FileReader(file));
writer = new BufferedWriter(new FileWriter(tempFile));
while((line = reader.readLine()) != null) {
String[] data = line.split(",");
if (this.usernameID.equals(data[0])) {
data[1] = ID;
line = String.join(",", data);
}
writer.write(line);
writer.newLine();
}
}
catch (IOException e) {
e.printStackTrace();
}
finally {
try {
if (reader != null) {
reader.close();
}
if (writer != null) {
writer.close();
}
}
catch (IOException e) {
e.printStackTrace();
}
}
if (!file.delete()) {
System.out.println("Could not delete file");
return;
}
if (!tempFile.renameTo(file)) {
System.out.println("Could not rename file");
}
}
}
}