Develop Reference

Simple program for making shifts

My dad asked me to make a program for him that will randomly take a name, surname etc. from Excel (or CSV file) and assign employees to the work. Each person must be at work minimum once and maximum 4 times a month. Program output should look like this:
Day 1: John Smith, James Smith Day 2: Charlie Smith, Thomas Smith
And this is how my code looks like right now
public static void main(String[] args) {
String FileName = "excel.csv";
File f = new File(FileName);
String read = "";
Map<Integer, Surname>SurnameArray = new HashMap<Integer, Surname>();
try {
Scanner scanner = new Scanner(f);
while(scanner.hasNextLine()) {
read = scanner.nextLine();
String[] arraySplit = read.split(",");
int kod = Integer.parseInt(tablicaSplit[0]);
String rank = tablicaSplit[1];
String name = tablicaSplit[2];
String surname = tablicaSplit[3];
SurnameArray.put(kod, new Nazwiska(kod, rank, name, surname));
SurnameArray.get(kod).getAll();
}
} catch (FileNotFoundException e) {
System.out.println("No file!");
}
}
}
And the second class looks like this:
Class Surnames {
private int kod;
private String rank;
private String name;
private String surname;
public Surnames(int kod, String rank, String name, String surname) {
super();
this.kod = kod;
this.rank = rank;
this.name = name;
this.surname = surname;
}
public void getAll() {
System.out.println(rank + " " + name + " " + surname);
}
public int getKod() {
return kod;
}
public void setKod(int kod) {
this.kod = kod;
}
public String getRank() {
return rank;
}
public void setRank(String rank) {
this.rank = rank;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSurname() {
return surname;
}
public void setNazwisko(String surname) {
this.surname = surname;
}
}
I'm stuck at this moment. I think that this code is more complicated than it should be. If someone could show me how can i make it or maybe there is simpler way to make something like this.

I would do it this way:
class Surnames{
private final HashSet<String> EMPLOYEES;
private ArrayList<String> positions;
Surnames(String csv){
HashSet<String> tempEMPLOYEES = new HashSet<>();
ArrayList<String> tempPositions = new ArrayList<>();
/*here the code for putting csv data ino an tempEMPLOYEE hashSet, or a static setter method doing this, as well for tempPositions, containing array list of positions remember to check
if the hashset's size is equal or lower than arrayList's*/
EMPLOYEES = tempEMPLOYEES;
positions = tempPosition;
}
public void printShift(){
for(int i = 0; i < EMPLOYEES.size(); i++){
System.out.println(positions.get(i) + "- " + EMPLOYEES.get(i));
}
}
}
Since hashSet gives different object position in the set every single run of the program, placing EMPLOYEES to positions will be random. I mentioned checking that HashSet EMPLOYEES should be less size than positions. I iterate on the hashset- every employee should get a position.

how to add strings from different arrays into one array in java

Hello I'm a bit confused with some coding problem I am trying to solve.
I have a few string arrays:
String[] firstNames= {"Fred","John","Amir", "James","Bob","Jay","Amber"};
String[] lastNames = {"Bond","Kates","Memar", "White","Marley","Brown","Nogofski"};
String[] idNumbers = {"R111111","A222222","AB11111", "KR22121","V311133","L242434","P102432"};
String[] employeeNum = {"1111","2222","3333", "4444","5555","6666","7777"};
I have to create one array and somehow organize the corresponding pieces of information provided above in the method Employee[] list = new Employee[firstNames.length];
list = listOfEmployees(firstNames,lastNames,idNumbers); // create the list of employees in one array
I started writing out the method:
public static Employee[] listOfEmployees(String[] firstName, String[]
lastName, String[] idNumber){
}
but not sure how to approach this. also not sure if my parameters are correct.
the end result is supposed to look like this:
Employee #1
first name:Fred Last Name:Bond
Id number:R111111
.
.
.
Employee #2
first name:John Last Name:Kates
Id number:A222222
and so on..
thanks in advance.
EDIT:
Employee class:
public class Employee{
private String firstName;
private String lastName;
private String idNumber;
private String employeeNumber;
private int employeeCount;
/**
* Constructor
* #param firstName first name
* #param lastName last name
* #param idNumber id number
*/
public Employee(String firstName, String lastName, String idNumber){
this.firstName = firstName;
this.lastName = lastName;
this.idNumber = idNumber;
employeeCount = 0;
}
/**
* Accessors here
*/
public String getFirstName(){
return firstName;
}
public String getLastName(){
return lastName;
}
public String getIdNumber(){
return idNumber;
}
public String getEmployeeNumber(){
return employeeNumber;
}
// mutators here
/**
* #param firstName first name
*/
public void setFirstName(String firstName){
this.firstName = firstName;
}
/**
* #param lastName last name
*/
public void setLastName(String lastName){
this.lastName = lastName;
}
/**
* #param idNumber id number
*/
public void setIdNumber(String idNumber){
this.idNumber = idNumber;
}
/**
* #param employeeNumber employee number
*/
public void setEmployeeNumber(String employeeNumber){
this.employeeNumber = "";
}
#Override
public String toString(){
String result = "First name: " + getFirstName() + "\nLast name: " + getLastName()
+ "\nId number: " + getIdNumber() + "\nEmployee number: ";
if(getEmployeeNumber() == null){
return result + "No employee number has been assigned yet!";
}
return result + getEmployeeNumber();
}
}

Please try the following:
private static Employee[] listOfEmployees(String[] firstNames, String[] lastNames, String[] idNumbers){
Employee[] list = new Employee[firstNames.length];
for(int i=0; i<list.length; i++){
list[i]=new Employee(firstNames[i], lastNames[i], idNumbers[i]);
}
return list;
}
To print the array returned by the above function, you may use:
private static void printEmployees(Employee[] employees){
for (Employee employee : employees) {
System.out.println("ID: "+employee.getIdNumber());
System.out.println("Name : "+employee.getFirstName()+" "+employee.getLastName());
System.out.println("------------------------------------");
}
}
And call them by following statement:
printEmployees(listOfEmployees(firstNames,lastNames,idNumbers));

Do a for loop and use the Employee constructor to initialize the objects:
Employee[] list = new Employee[firstNames.length];
for (int i = 0; i < firstName.length; i++) {
list[i] = new Employee(firstName[i], lastName[i] ...
}

Try this
public class Test{
public static void main(String[] args){
String[] firstNames= {"Fred","John","Amir", "James","Bob","Jay","Amber"};
String[] lastNames = {"Bond","Kates","Memar", "White","Marley","Brown","Nogofski"};
String[] idNumbers = {"R111111","A222222","AB11111", "KR22121","V311133","L242434","P102432"};
String[] employeeNum = {"1111","2222","3333", "4444","5555","6666","7777"};
List<Employee> list = new ArrayList<>();
for(int i=0;i<firstName.length();i++){
list.add(new(Employee(firstName[i],lastName[i],idNumbers[i],employeeNumber[i]))}
}}

"cannot be converted to String[] by method invocation conversion"

I am sure this is something stupid, but I can't figure it out for the life of me.... In the main method, when I am trying to create new artists, I keep getting an error on the creating a new "Recording" line (ie: surfacing and pop). It is saying it requires String, String[] but is getting String, MusicCollection.Artist. And it says "actual argument MusicCollection.Artist cannot be converted to String[] by method invocation conversion.
public class MusicCollection {
private Artist[] artists = new Artist[100];
private Recording[] recordings = new Recording[200];
private int artistCount = 0;
private int recordingCount = 0;
//toString method for MusicCollection
public String toString() {
StringBuffer sb = new StringBuffer();
if (recordingCount > 0) {
sb.append(recordings[0].toString());
for (int i = 1; i < recordingCount; i++) {
sb.append("\n" + recordings[i]);
}
}
return sb.toString();
}
public class Artist {
private String name;
/**
* Construct an artist object and add it to the collection.
*
* #param name the name of the Artist
*/
public Artist(String name) {
this.name = name;
artists[artistCount++] = this;
}
/**
* Retrieve the artist as a string
*
* #return the string representation of the artist
*/
public String toString() {
return name;
}
}
public class Recording {
private String name;
private Artist[] artists = new Artist[100];
private Track[] tracks = new Track[200];
private int trackCount = 0;
public class Track {
private String name;
/**
* Construct track object and add it to the collection.
*
* #param name the name of the track
*/
public Track(String name) {
this.name = name;
tracks[trackCount++] = this;
}
/**
* Retrieve the track as a string
*
* #return the string representation of the track
*/
public String toString() {
return name;
}
}
public Recording(String name, String Artist[]) {
this.name = name;
this.artists = artists;
recordings[recordingCount++] = this;
}
public String toString() {
StringBuffer sb = new StringBuffer(name);
sb.append(" by " + artists + ": ");
if (trackCount > 0) {
sb.append(tracks[0].toString());
for (int i = 1; i < trackCount; i++) {
sb.append(", " + tracks[i]);
}
}
return sb.toString();
}
}
public static void main(String[] args) {
MusicCollection mc = new MusicCollection();
Artist sarahM = mc.new Artist("Sarah McLachlan");
Recording surfacing = mc.new Recording("Surfacing", sarahM);
Recording.Track surfacing1 = surfacing.new Track("Building a Mystery");
Recording.Track surfacing4 = surfacing.new Track("Adia");
Artist u2 = mc.new Artist("U2");
Recording pop = mc.new Recording("Pop", u2);
Recording.Track pop1 = pop.new Track("Discotheque");
Recording.Track pop5 = pop.new Track("Miami");
System.out.println(mc);
}
}

Needed to have:
public Recording(String name, Artist someArtist)
and in my Recording class, only have:
private Artist artist;
since I had already declared Artist as an array.
I also had to change this.artists = artists; to this.artists = someArtist;, since that was the variable I am passing. Worked like a charm after!

toString method and searching a list for string equality

This is an Object Oriented program with two classes Catalog and Products that reads a file that contains the product name, quantity, and price, adds them to a list array, and calculate the total Price of the items. Everything works with my program except that it has a toString method that when I ran the program it prints something like this #445ea7e I think this happens because the addProducts() and getProducts(String name) on the Catalog class has to do something with the toString() and I don't know how to connect them to work.
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class Catalog{
private static int MAX_ITEMS = 10;
/**
* List of Products objects.
*/
private Products[] list;
private int nextItem;
/**
* Default constructor
*/
public Catalog(){
list = new Products[MAX_ITEMS];
nextItem = 0;
}
/**
* Adds an item to the list
*/
public void addProducts (String name, int quantity, double price){
**//I tried this: list[nextItem] = new Products(name, quantity, price);
//but I'm not sure if that's ok.**
}
/**
* Reads items from an input file.
*/
public void loadList(String fileName)
throws FileNotFoundException {
if ( (fileName != null) && (!fileName.equals("")) ) {
Scanner input = new Scanner(new File(fileName));
String newLine = null;
String name = null;
int quantity = 0;
double price = 0.0;
while (input.hasNextLine() && nextItem < MAX_ITEMS) {
if (input.hasNext()) {
name = input.next();
} else {
System.err.println("ERROR Not a String");
System.exit(2);
}
if (input.hasNextInt()) {
quantity = input.nextInt();
} else {
System.err.println("ERROR Not an integer");
System.exit(2);
}
if (input.hasNextDouble()) {
price = input.nextDouble();
} else {
System.err.println("ERROR Not a double");
System.exit(2);
}
list[nextItem] = new Products(name, quantity, price);
newLine = input.nextLine();
nextItem += 1;
}
}
return;
}
/**
* Calculate the total cost of products.
*/
public double getTotalPrice(){
double total = 0.0;
for(int i=0; i < nextItem; i++){
Products products = list[i];
total+=products.getTotalPrice();
}
return total;
}
/**
* Search Catalog items with a product name
*/
public Products getProducts(String name){
**//search a list for string equality using the name of the product and returns it to the caller**
}
public static void main(String[] args)
throws FileNotFoundException {
Catalog catalog= new Catalog();
catalog.loadList(args[0]);
System.out.println();
//System.out.println(toString()); **I don't know how to call toString**
System.out.println();
System.out.format("Total Price = %9.2f\n", catalog.getTotalPrice());
}
}
This is the Products class with the toString() method.
public class Products {
private String name;
private int quantity;
private double price;
/**
* Constructor.
*/
public Products(String name, int quantity, double price){
this.name = name;
this.quantity = quantity;
this.price = price;
}
/**
* Gets name of the product.
*/
public String getName(){
return this.name;
}
/**
* Gets the quantity of products.
*/
public int getQuantity(){
return this.quantity;
}
/**
* Gets the cost per product.
*/
public double getPrice(){
return price;
}
/**
* set quantity of the products.
*/
public void setQuantity(int quantity){
this.quantity=quantity;
}
/**
* Calculate the total price.
*/
public double getTotalPrice(){
return quantity * price;
}
/**
* Returns a spaced-separated list of the attributes.
*/
public String toString(){
String s=null;
s+=getName();
s+=s + " ";
s+=getQuantity();
s+=s + " ";
s+=getPrice();
return s;
}
}
This is the file with the Products information
Football 2 15.50
ChapStick 1 3.87
Book 4 10.00

You add toString() to your Catalog class as Product class :
public class Catalog {
private static int MAX_ITEMS = 10;
/**
* List of Products objects.
*/
private Products[] list;
private int nextItem;
// your old code here
// new code
#Override
public String toString() {
return "this is a catalog";
}
}
You call catalog.toString():
public static void main(String[] args)
throws FileNotFoundException {
Catalog catalog= new Catalog();
catalog.loadList(args[0]);
System.out.println();
//System.out.println(toString()); **I don't know how to call toString**
// use this line
System.out.println(catalog.toString());
System.out.println();
System.out.format("Total Price = %9.2f\n", catalog.getTotalPrice());
}
In your toString() method of Product class. you should change initialize variable from s=null; to s="";. Here is sample :
public String toString(){
String s="";
s+=getName();
s+=s + " ";
s+=getQuantity();
s+=s + " ";
s+=getPrice();
return s;
}
Hope this help :)

In your toString() method (in products class), change
String s = null;
to
String s = "";
Also, you have to make a toString method for the Catalog class in order to call it.
An example toString method for catalog class can be:
public String toString(){
String toReturn = "";
for(Products current: list){
toReturn+=current.toString()+"\n";
}
return toReturn;
}
Then if main just call, System.out.println(catalog.toString());

Try adding override to your toString method this might be the solution base on your current output.
#Override
public String toString(){
String s=null;
s+=getName();
s+=s + " ";
s+=getQuantity();
s+=s + " ";
s+=getPrice();
return s;
}

can't get the personal customer class to compile, something wrong with the constructor? [closed]

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Closed 9 years ago.
It's a simple program to add/remove different types of customers.
I know it's probably something simple, but has had me for a while now.
Keep getting the error,
constructor Customer in class Customer cannot be applied to the given types; required; java.lang. String, Address, char found:no arguments reason: actual and formal argument lists differ in length
I'm guessing it's something to do with the customer constructor but don't know.
public class Address
{
private String street,town;
/**
* Constructor for Address
*
* #param street The street
* #param town The town
*/
public Address (String street, String town)
{
this.street = street;
this.town = town;
}
/**
* #return The street
*/
public String getStreet()
{
return street;
}
/**
* #return The town
*/
public String getTown()
{
return town;
}
/**
* Change the street part of the address
*
* #param street The new street
*/
public void setStreet(String street)
{
this.street = street;
}
/**
* Change the town part of the address
*
* #param street The new town
*/
public void setTown(String town)
{
this.town = town;
}
public String toString()
{
return street + "\n" + town;
}
}
public class Name
{
private String fName, lName;
/**
* Constructor for Name
*
* #param fName The first name
* #param lName The last name
*/
public Name(String fName, String lName)
{
this.fName = fName;
this.lName = lName;
}
/**
* #return The first name
*/
public String getFName()
{
return fName;
}
/**
* #return The last name
*/
public String getLName()
{
return lName;
}
/**
* Amend the first name
*
* #param fName The new first name
*/
public void setFName(String fName)
{
this.fName = fName;
}
/**
* Amend the last name
*
* #param lName The new last name
*/
public void setLName(String lName)
{
this.lName = lName;
}
public String toString()
{
return fName + " " + lName;
}
}
public class Customer
{
// instance variables - replace the example below with your own
private String accountNumber;
private Address address;
private int balance;
private char customerType;
/**
* Constructor for objects of class Customer
*/
public Customer(String accountNumber, Address address, char customerType)
{
// initialise instance variables
this.accountNumber= accountNumber;
this.address= address;
balance = 0;
this.customerType=customerType;
}
/**
* Adds money to the ammount in the account
*/
public void credit(int amt)
{
balance= balance + amt;
}
/**
* removes money from the ammount in the account
*/
public void debit(int amt)
{
balance= balance - amt;
}
/**
* Returns the account number of the customer
*/
public String getAccountNumber()
{
return accountNumber;
}
/**
* returns the address of the customer
*/
public Address getAddress()
{
return address;
}
/**
* returns the balance of the customer
*/
public int getBalance()
{
return balance;
}
/**
* Returns the type of customer Bussiness or Personal
*/
public char getCustomerType()
{
return customerType;
}
public void setAddress(Address address)
{
this.address=address;
}
public String toString()
{
String output ="Account Number: " + accountNumber + "Customer Type: " + customerType + "balance: " + getBalance() + "Address: " + super.toString();
return output;
}
}
public class PersonalCustomer extends Customer
{
// instance variables
private Name name;
public PersonalCustomer(String accountNumber, Address address, Name name)
{
// initialise instance variables
this.accountNumber= accountNumber;
this.address=address;
this.name= Name;
}
public Name getName()
{
return + "Address: " + super.toString();
}
public void print()
{
System.out.println(toString());
}
public String toString()
{
String output = getFName() + getLName() + "\n" + "Account Number: " + accountNumber + "\n"
+ "Customer Type: " + customerType + "\n" + "Address: " + super.toString() + "\n"
+ "balance: " + getBalance();
return output;
}
}

The error message is saying you are calling:
new Customer();
but the customer requires a String, Address and char eg:
new Customer("Bob", new Address("Cool Street","Awesome Town"), 'a');
This seems a bit odd but the reason is that your child class implicitly calls the parent constructor if you don't.
public PersonalCustomer(String accountNumber, Address address, Name name)
{
// super(); //calls the parent constructor with no arguments without you seeing
this.accountNumber= accountNumber;
this.address=address;
this.name= Name;
}
All you need to do is change the PersonalCustomer constructor to
public PersonalCustomer(String accountNumber, Address address, Name name)
{
super(accountNumber, address, 'p'); //or whatever customer type they are supposed to get
this.name= Name;
}

If you don't define a constructor, there's an implicit no-args constructor.
But, when you define a constructor with arguments, the implicit no-rags constructor disappears.
You must have had some code prior to defining the new constructor that used the default constructor, ie new Customer(). You must define a no-args constructor to fox your problem
This little gem catches out many a new java programmer.