Question

(Reading & Writing Business Objects)

I need to have my Classes be able to talk to Files.

How do I make it such that I can look in a File for an account number and I am able to pull up all the details? The file should be delimited by colons (":"). The Code for testing 'Select' that goes in main is:

Account a1 = new Account();

a1.select(“90001”);

a1.display();

Below is what it should look like for accounts

90000:3003:SAV:8855.90

& Below for customers.

3003:6789:Terry:March:Texas:[email protected]

I have some Accounts saved in an Accounts.txt file and Customers in a Cutomers.txt file.

I have my code below.

**********************************************************************************************

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Scanner;
import java.util.StringTokenizer;

public class Account2{
//Properties
private int accountNo;
private int customerId;
private String accountType;
private double balance;
//Constructors
public Account2(){
accountNo = 0;
customerId = 0;
accountType = "";
balance = 0.0;
}
public Account2(int acc, int cid, String accType, double bal){
accountNo = acc;
customerId = cid;
accountType = accType;
balance = bal;
}
//Behaviors
public void setAccNo(int acc){
accountNo = acc;
}
public int getAccNo(){
return accountNo;
}
public void setCid(int cid){
customerId = cid;
}
public int getCid(){
return customerId;
}
public void setAccType(String accType){
accountType = accType;
}
public String getAccType(){
return accountType;
}
public void setBal(double bal){
balance = bal;
}
public double getBal(){
return balance;
}
public void display(){
System.out.println("===================== ");
System.out.println("Account Number: " + getAccNo());
System.out.println("Customer ID: " + getCid());
System.out.println("Account Type: " + getAccType());
System.out.println("Balance: $" + getBal());
System.out.println("");
}
public void select(String accNo){   
accountNo = 0;
accountType = "";
balance = 0;
customerId = 0;
try{
String line;
File f1 = new File("Accounts.txt");
Scanner inFile = new Scanner(f1);
while(inFile.hasNextLine()){
line = inFile.nextLine();
StringTokenizer tokenizer = new StringTokenizer(line, ":");
String token = tokenizer.nextToken();
System.out.println(token);
if(token.equals(accNo)){
accountNo = Integer.parseInt(token);
customerId = Integer.parseInt(tokenizer.nextToken());
accountType = tokenizer.nextToken();
balance = Double.parseDouble(tokenizer.nextToken());
break;
}
}
inFile.close();
}
catch(IOException ie){
System.out.println(ie);
}
}
public static void main(String[] args){
Account2 a1 = new Account2();
a1.select("90001");
a1.display();
}
}

*******************************************************************************************

public class Person2{
//Properties
private String firstName;
private String lastName;
private String address;
private String email;
//Constructors
public Person2(){
firstName = "";
lastName = "";
address = "";
email = "";
}
public Person2(String fn, String ln, String addr, String em ){
firstName = fn;
lastName = ln;
address = addr;
email = em;
}
//Behaviors
public void setFn(String fn){
firstName = fn;
}
public String getFn(){
return firstName;
}
public void setLn(String ln){
lastName = ln;
}
public String getLn(){
return lastName;
}
public void setAddr(String addr){
address = addr;
}
public String getAddr(){
return address;
}
public void setEm(String em){
email = em;
}
public String getEm(){
return email;
}
public void display(){
System.out.println("");
System.out.println("First Name: " + getFn());
System.out.println("Last Name: " + getLn());
System.out.println("Address: " + getAddr());
System.out.println("E-Mail: " + getEm());
System.out.println("");
}

public static void main(String[] args){
Person2 p2;
p2 = new Person2("Billy","Carter","Georgia","[email protected]");
p2.display();
Person2 p3;
p3 = new Person2("Tony","Danza","Atlanta","[email protected]");
p3.display();
}
}

******************************************************************************************************

import java.io.File;
import java.io.IOException;
import java.util.Scanner;
import java.util.StringTokenizer;

public class Customer2 extends Person2{
//Properties
public int password;
public int customerID;
public AccountList2 list;
//Constructors
public Customer2(){
super();
list = new AccountList2();
password = 0;
customerID = 0;
}
public Customer2(int pw, int cid ,String fn, String ln, String addr, String em){
super(fn, ln, addr, em);
password = pw;
customerID = cid;
list = new AccountList2();
}
//Behaviors
public void setPw(int pw){
password = pw;
}
public int getPw(){
return password;
}
public void setList(AccountList2 li){
list = li;
}
public AccountList2 getList(){
return list;
}
public void setCid(int cid){
customerID = cid;
}
public int getCid(){
return customerID;
}
public void addAccount(Account2 acc){
list.addAccount2(acc);
}

public void display(){
System.out.println("");
System.out.println("Password: " + getPw());
System.out.println("Customer ID: " + getCid());
super.display();
list.display();
System.out.println("");
}
public void select(String custId){
try{
customerID = 0;
password = 0;
setFn(null);
setLn(null);
setEm(null);
setAddr(null);
  
String line;
File f1 = new File("Customer.txt");
Scanner inFile = new Scanner(f1);
while(inFile.hasNextLine()){
line = inFile.nextLine();
StringTokenizer tokenizer = new StringTokenizer(line, ":");
String token = tokenizer.nextToken();
System.out.println(token);
if(token.equals(custId)){
customerID = Integer.parseInt(token);
password = Integer.parseInt(tokenizer.nextToken());
setFn(tokenizer.nextToken());
setLn(tokenizer.nextToken());
setAddr(tokenizer.nextToken());
setEm(tokenizer.nextToken());
list = new AccountList2();
Scanner accFile = new Scanner(new File("Accounts.txt"));
while(accFile.hasNextLine())
{
tokenizer = new StringTokenizer(accFile.nextLine(), ":");
String accNo = tokenizer.nextToken(); // acount number
String cid = tokenizer.nextToken();
if(cid.equals(custId))
{
acc.setAccNo(Integer.parseInt(accNo));
acc.setCid(Integer.parseInt(cid));
acc.setAccType(tokenizer.nextToken());
acc.setBal(Double.parseDouble(tokenizer.nextToken()));
list.add(Integer.parseInt(accNo));
}
}
accFile.close();
break;
}
}
inFile.close();
}
catch(IOException ie){
System.out.println(ie);
}   
}
public static void main(String[] args){
Customer2 c2;
c2 = new Customer2();
c2.display();

c2.select("3003");
c2.display();
}
}

******************************************************************************************************************

public class AccountList2{
//Properties
public int count = 0;
public Account2 aList[] = new Account2[4];
//Constructors
public AccountList2(){
}
//Behaviors
public void addAccount2(Account2 a2){
aList[count] = a2;
count++;
}
public void display(){
System.out.println("=====================");
System.out.println("Account List Display");
for(int x = 0; x < count; x++){
aList[x].display();
}
}
public static void main(String[] args){
AccountList2 myList = new AccountList2();
myList.addAccount2(new Account2(90000,3003,"SAV",8855.90));
myList.addAccount2(new Account2(90001,3003,"CHK",786.54));
myList.display();
}
}

*****************************************************************************************************************************

Answer 1

Hi, Inorder to open your file in a scanner you must follow these steps.

//get the url of your text file
URL path = ClassLoader.getSystemResource("Customer.txt");
// give the path to file
File f = new File(path.toURI());
//open the file in scanner

Scanner inFile = new Scanner(f);

YOUR CODE:

Customer2.java

/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/

package Accounts;

/**
*
* @author miracle
*/
import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Scanner;
import java.util.StringTokenizer;
public class Customer2 extends Person2{
//Properties
public int password;
public int customerID;
public AccountList2 list;
//Constructors
public Customer2(){
super();
list = new AccountList2();
password = 0;
customerID = 0;
}
public Customer2(int pw, int cid ,String fn, String ln, String addr, String em){
super(fn, ln, addr, em);
password = pw;
customerID = cid;
list = new AccountList2();
}
//Behaviors
public void setPw(int pw){
password = pw;
}
public int getPw(){
return password;
}
public void setList(AccountList2 li){
list = li;
}
public AccountList2 getList(){
return list;
}
public void setCid(int cid){
customerID = cid;
}
public int getCid(){
return customerID;
}
public void addAccount(Account2 acc){
list.addAccount2(acc);
}
public void display(){
System.out.println("");
System.out.println("Password: " + getPw());
System.out.println("Customer ID: " + getCid());
super.display();
list.display();
System.out.println("");
}
public void select(String custId) throws URISyntaxException{
try{
customerID = 0;
password = 0;
setFn(null);
setLn(null);
setEm(null);
setAddr(null);
Account2 acc=new Account2();
String line;

URL path = ClassLoader.getSystemResource("Customer.txt");
System.out.println("path is "+path);
File f = new File(path.toURI());


// Scanner input = new Scanner(f);
// File f1 = new File("Customer.txt");
Scanner inFile = new Scanner(f);
while(inFile.hasNextLine()){
line = inFile.nextLine();
StringTokenizer tokenizer = new StringTokenizer(line, ":");
String token = tokenizer.nextToken();
System.out.println(token);
if(token.equals(custId)){
customerID = Integer.parseInt(token);
password = Integer.parseInt(tokenizer.nextToken());
setFn(tokenizer.nextToken());
setLn(tokenizer.nextToken());
setAddr(tokenizer.nextToken());
setEm(tokenizer.nextToken());
list = new AccountList2();

URL path1 = ClassLoader.getSystemResource("Accounts.txt");
System.out.println("path1 is "+path);
File f1 = new File(path1.toURI());


// Scanner input = new Scanner(f);
Scanner accFile = new Scanner(f1);
while(accFile.hasNextLine())
{
tokenizer = new StringTokenizer(accFile.nextLine(), ":");
String accNo = tokenizer.nextToken(); // acount number
String cid = tokenizer.nextToken();
if(cid.equals(custId))
{
acc.setAccNo(Integer.parseInt(accNo));
acc.setCid(Integer.parseInt(cid));
acc.setAccType(tokenizer.nextToken());
acc.setBal(Double.parseDouble(tokenizer.nextToken()));
//list.add(Integer.parseInt(accNo));
}
}
accFile.close();
break;
}
}
inFile.close();
}
catch(IOException ie){
System.out.println(ie);
}   
}
public static void main(String[] args) throws URISyntaxException{
Customer2 c2;
c2 = new Customer2();
c2.display();

c2.select("3003");
c2.display();
}
}

Account2.java

/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/

package Accounts;

/**
*
* @author miracle
*/

import java.io.*;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Scanner;
import java.util.StringTokenizer;
public class Account2{
//Properties
private int accountNo;
private int customerId;
private String accountType;
private double balance;
//Constructors
public Account2(){
accountNo = 0;
customerId = 0;
accountType = "";
balance = 0.0;
}
public Account2(int acc, int cid, String accType, double bal){
accountNo = acc;
customerId = cid;
accountType = accType;
balance = bal;
}
//Behaviors
public void setAccNo(int acc){
accountNo = acc;
}
public int getAccNo(){
return accountNo;
}
public void setCid(int cid){
customerId = cid;
}
public int getCid(){
return customerId;
}
public void setAccType(String accType){
accountType = accType;
}
public String getAccType(){
return accountType;
}
public void setBal(double bal){
balance = bal;
}
public double getBal(){
return balance;
}
public void display(){
System.out.println("===================== ");
System.out.println("Account Number: " + getAccNo());
System.out.println("Customer ID: " + getCid());
System.out.println("Account Type: " + getAccType());
System.out.println("Balance: $" + getBal());
System.out.println("");
}
public void select(String accNo) throws FileNotFoundException, URISyntaxException{   
accountNo = 0;
accountType = "";
balance = 0;
customerId = 0;
try{
String line;

URL path = ClassLoader.getSystemResource("Account.txt");
System.out.println("path is "+path.toString());
File f = new File(path.toURI());
Scanner inFile = new Scanner(f);
while(inFile.hasNextLine()){
line = inFile.nextLine();
StringTokenizer tokenizer = new StringTokenizer(line, ":");
String token = tokenizer.nextToken();
System.out.println(token);
if(token.equals(accNo)){
accountNo = Integer.parseInt(token);
customerId = Integer.parseInt(tokenizer.nextToken());
accountType = tokenizer.nextToken();
balance = Double.parseDouble(tokenizer.nextToken());
break;
}
}
inFile.close();
}
catch(IOException ie){
System.out.println(ie);
}
}
public static void main(String[] args) throws FileNotFoundException, URISyntaxException{
Account2 a1 = new Account2();
a1.select("9000");
a1.display();
}
}

Please do comment in case of queries. Thanks.