Develop Reference

Java array list returning 0 value

I have created a class like this, which contains a bunch of arraylist as you can see. I've been setting the array with the methods add.. and then retrieving it with get.., when i tried to System.out.println numberofcitizen for example it is returning 0. Note that i have instantiated the class in another class to set the values.
public int numberOfCitizen;
private final ArrayList<Integer> citizenid = new ArrayList<>();
private final ArrayList<String> citizenName = new ArrayList<>();
private final ArrayList<Integer> citizenWaste = new ArrayList<>();
private final ArrayList<Float> longitude = new ArrayList<>();
private final ArrayList<Float> latitude = new ArrayList<>();
private final ArrayList<String> address = new ArrayList<>();
public void working() {
System.out.println("executing fine");
}
public void setnoOfcit(int number) {
this.numberOfCitizen = number;
}
public int getnumber() {
return this.numberOfCitizen;
}
public void addCitizenId(int citizen) {
citizenid.add(citizen);
}
public int getCitizenid(int i) {
int citId = citizenid.get(i);
return citId;
}
public void addCitizenName(String citizenname) {
citizenName.add(citizenname);
}
public String getCitizenName(int i) {
return citizenName.get(i);
}
public void addCitizenWaste(int waste) {
citizenWaste.add(waste);
}
public int getCitizenWaste(int i) {
return citizenWaste.get(i);
}
public void addLatitude(float lat) {
latitude.add(lat);
}
public float getLat(int i) {
return latitude.get(i);
}
public void addlng(float lng) {
longitude.add(lng);
}
public float getlng(int i) {
return longitude.get(i);
}
com.graphhopper.jsprit.core.problem.VehicleRoutingProblem.Builder vrpBuilder = com.graphhopper.jsprit.core.problem.VehicleRoutingProblem.Builder.newInstance();
public void runVPRSolver() {
System.out.println(numberOfCitizen);
System.out.println(getCitizenName(0));
//create a loop to fill parameters

Probable source of problem :
numberOfCitizen is a member attribute that you seem to never change. If you want it to represent the number of elements in your lists, either use citizenName.size() or increment the value of numberOfCitizen in one of the add methods.
Design flaw :
Your design takes for granted that your other class always use that one properly. Anytime you or someone uses that class, he must make sure that he add every single element manually. This adds code that could be grouped inside your class, which would be cleaner and easier to maintain.
So instead of several add method like this :
addCitizenid();
addCitizenName();
addCitizenWaste();
addLongitude();
addLatitude();
addAddress();
Design an other Citizen class which will contain those elements, and use a single list of instances of that class. That way you can use only one method :
private List<Citizen> citizenList = new ArrayList<>();
public void addCitizen(Citizen c) {
/*Add element in your list*/
citizenList.add(c);
}
This programming methodology is called "Encapsulation" which you can read about here

You need to increment numberOfCitizen in your add methods. For example:
public void addCitizenId(int citizen){
citizenid.add(citizen);
numberOfCitizen++;
}
I would also suggest encapsulating your variables into Objects, so create a citizen class:
public class Citizen {
private Integer id;
private Integer name;
private Integer waste;
}
And change your variable to an ArrayList of objects:
ArrayList<Citizen> citizens;

Detecting Class of an object implementing an interface

I'm writing a game, as part of this players should be able to click on various GUI items and see further details on a specific area of the GUI. I'm mangaing this through an interface Detailable which is implemented by suitable game obects and sends the appropriate information to the JPanel
There are also containers (all of which implement Detailable) that contain other (Detailable implementing) objects. The goal being it is possible to click on a container and, amongst its stats, see its contents which can then be in turn clicked on to see their stats, etc.
The problem I am having is in writing the addToContents(Detailable d) method of my containers. Each container as an ArrayList<String> of the "type" of container - wardrobe, bookcase, etc. I want to be able to add only certain classes to a given container - so a container with a type of "bookcase" will only accept objects of class Book or Curio for example.
What I currently have is:
public boolean addToContents(Detailable d){
if(this.types.contains("bookcase") && d.getClass().getName().equals("Book")){
//do some stuff
//I know "Book" isn't the right syntax, this is just to demo
return true;
}
else if(this.types.contains("bookcase") && d.getClass().getName().equals("Curio")){
//other stuff
return true;
}
//etc
else{
return false;
}
}
But this feels like the wrong way of doing it. Is there a better way? Ideally, for sake of easy code, I'd have something like (pseudocode)
Constructor:
private ArrayList<Class> classesAccepted = <list of classes>
addToContents:
if (classesAccepted.contains(d.getClass()){
add the thingie to contents
return true
}
else{
return false;
}
but I can't seem to find a way of adding a list of classes to the constructor - of translating the ArrayList of class names to an ArrayList of references to the actual class.
Containers are currently read from a JSON so comprise two classes:
public class FurnitureType {
private String name;
private List<String> type;
private int cost;
private String description;
private int comfortBonus;
private int capacity;
//plus getters for all the above
}
public class Furniture implements Detailable, ListSelectionListener{
private String name;
private List<String> types;
private int cost;
private String description;
private int comfortBonus;
private int capacity;
private ArrayList<Detailable> contents;
private transient DetailPanel dp = null;
public Furniture (FurnitureType type){
this.name=type.getName();
this.types = type.getType();
this.cost = type.getCost();
this.description = type.getDescription();
this.comfortBonus = type.getComfortBonus();
this.capacity = type.getCapacity();
this.contents = new ArrayList();
}
//appropriate getters
public boolean addToContents(Detailable d){
if(this.types.contains("bookcase") && d.getClass().getName().equals("Book")){
//do some stuff
//I know "Book" isn't the right syntax, this is just to demo
return true;
}
else if(this.types.contains("bookcase") && d.getClass().getName().equals("Curio")){
//other stuff
return true;
}
//etc
else{
return false;
}
}
#Override
public String toString(){
return description;
}
#Override
public Icon getBigPic() {
return null;
}
#Override
public JComponent getStats() {
Object [] objectContents = contents.toArray();
JList contentList = new JList(objectContents);
contentList.setPreferredSize(new Dimension (400, 300));
contentList.setFixedCellHeight(50);
contentList.addListSelectionListener(this);
contentList.setCellRenderer(new CustomCellRenderer());
//the CustomCellRenderer class simply makes long descriptions into multiline cells
return contentList;
}
#Override
public void addPanel(DetailPanel dp) {
this.dp = dp;
}
#Override
public void valueChanged(ListSelectionEvent lse) {
Detailable d = contents.get(lse.getFirstIndex());
dp.updatePanel(d);
}

You can actually use a Map as shown below:
private static Map<String, List<Class<? extends Detailable>>>
bookcaseContainer = new HashMap<>();
static {
//load the bookcaseContainer Map from properties/database
bookcaseContainer.put("bookcase", list1);
bookcaseContainer.put("wardrobe", list2);
}
if(bookcaseContainer.get("bookcase") != null &&
bookcaseContainer.get("bookcase").contains(d.getClass())) {
//do something here
} else if(bookcaseContainer.get("wardrobe") != null &&
bookcaseContainer.get("wardrobe").contains(d.getClass())) {
//do something here
}

If I understand your question correctly, you are looking for something like this
ArrayList <Class<? extends Detailable>> acceptedClasses = new ArrayList<>();
acceptedClasses.add(Bookcase.class);
acceptedClasses.add(OtherAcceptable.class);
and then do something akin to
boolean test =
acceptedClasses.stream().anyMatch(clazz -> aClass.isInstance(detailableInstance));
to check if the instance is of an acceptable type

Hibernate One-To-Many Mapping, printing mapped lists

I have used One-to-Many Mapping in my project. I have stored a list of clicks for every user.
But when I retrieve the list by calling getClicks() methodm Hibernate returns list in different format.
Something like this.
"[com.zednx.tech.persistence.Click#29df9a77]"
So I tried Reading Every value from the list and assign to a new List.
List<Click> clicks=new ArrayList<Click>();
for(Click c: e.getClicks()){
Click temp = new Click();
temp.setAff_source(c.getAff_source());
temp.setCb_to_award(c.getCb_to_award());
temp.setCb_type(c.getCb_type());
clicks.add(temp);
}
But when i print the items of new List it stills prints the same way.
I need to build a JSON from the resulting String of this list.
So if the list is returned in format, it wont help me.
I couldn't find anything regarding this except How to pretty print Hibernate query results?
I tried Arrays.ToString(Object o). But it doesn't work.
GSON builder part-
Gson gson = new GsonBuilder()
.registerTypeAdapter(Click.class, new MyTypeAdapter<Click>())
.create();
List<Click> clicks=new ArrayList<Click>();
for(Click c: e.getClicks()){
Click temp = new Click();
temp.setAff_source(c.getAff_source());
temp.setCb_to_award(c.getCb_to_award());
temp.setCb_type(c.getCb_type());
temp.setCom_to_recieve(c.getCom_to_recieve());
temp.setStore_name(c.getStore_name());
temp.setT_date(c.getT_date());
temp.setT_status(c.getT_status());
temp.setT_ticket(c.getT_ticket());
temp.setUid(c.getUid());
System.out.println(c.toString());
clicks.add(temp);
}
String json = gson.toJson(clicks, Click.class);
Click.java
#Entity
#Table(name="click")
public class Click {
#Id
#Column(name="t_ticket")
private String t_ticket;
#Column(name="uid",nullable=false)
private long uid;
public long getUid() {
return uid;
}
public void setUid(long uid) {
this.uid = uid;
}
#ManyToOne
#JoinColumn(name="uid",
insertable=false, updatable=false,
nullable=false)
private Earning earning;
#Column(name="store_name")
private String store_name;
#Column(name="t_status")
private String t_status;
#Column(name="aff_source")
private String aff_source;
#Column(name="com_to_recieve")
private float com_to_recieve;
#Column(name="t_date")
private Date t_date;
#Column(name="cb_to_award")
private float cb_to_award;
#Column(name="cb_type")
private String cb_type;
public String getT_ticket() {
return t_ticket;
}
public void setT_ticket(String t_ticket) {
this.t_ticket = t_ticket;
}
public Earning getEarning() {
return earning;
}
public void setEarning(Earning earning) {
this.earning = earning;
}
public String getStore_name() {
return store_name;
}
public void setStore_name(String store_name) {
this.store_name = store_name;
}
public String getT_status() {
return t_status;
}
public void setT_status(String t_status) {
this.t_status = t_status;
}
public String getAff_source() {
return aff_source;
}
public void setAff_source(String aff_source) {
this.aff_source = aff_source;
}
public float getCom_to_recieve() {
return com_to_recieve;
}
public void setCom_to_recieve(float com_to_recieve) {
this.com_to_recieve = com_to_recieve;
}
public Date getT_date() {
return t_date;
}
public void setT_date(Date t_date) {
this.t_date = t_date;
}
public float getCb_to_award() {
return cb_to_award;
}
public void setCb_to_award(float cb_to_award) {
this.cb_to_award = cb_to_award;
}
public String getCb_type() {
return cb_type;
}
public void setCb_type(String cb_type) {
this.cb_type = cb_type;
}
Any Help is appreciated.

You need to implement a toString method, as your current Click class likely doesn't have one, so it just prints as the name of the class and instance identifier.

Okay, I could solve my problem finally.
I made another POJO without any annotations and Mapped the List items to that POJO class.
I think the problem was with Annotation of mapping on another class which I had in original POJO.
Also getString() method only helps in changing format of identifier. So basically it has nothing to do with JSON building unless you format getString() in form of JSON.
Hope it helps. If anyone wants new temp POJO I made I can post it if requested.
Thanks.

Multiple products in a single client(arrayList)

I've been asked to program a small online sales aplication.
It sounds very simple in theory (but it's been a hell for me). I'm just supposed to have an arrayList with about 5 products and then have a client buy 1 to 5 products and print the sales total.
public class Product {
private String name;
private double price;
public Product(String name, double price) {
this.name = name;
this.price = price;
}
public String getName() {
return name;
}
public double getPrice() {
return price;
}
public String printInfo() {
return "Product: " + name + " Cost: " + price;
}
}
Then I have a client class:
public class Cliente {
private String name;
private int numPedido;
ArrayList<Producto> products = new ArrayList<Producto>();
public void listBuilder() {
Producto shirt = new Producto("Shirt", 30);
Producto tshirt = new Producto("T-Shirt", 40);
Producto sweater = new Producto("Sweater", 50);
}
public Cliente(String name, int numPedido) {
this.name = name;
this.numPedido = numPedido;
}
public Cliente() {
}
public String getName() {
return name;
}
public int getNumPedido() {
return (int) (Math.random() * 100);
}
public void addNewClient() {
name = JOptionPane.showInputDialog("Nombre: ");
}
public String printInfo() {
return "Nombre: " + name;
}
}
Right now I'm stuck thinking on how to make a client select a product and get that attached to him. I was thinking on making an arrayList of an arrayList but I'm sure that would complicate things. I know there is probably an easier way to connect them but I can't think of any. The option I have in mind is a method which shows numbers from 1 to 3(corresponding to each product) and when the user picks one it should return the price of the item.
Still not sure how to implement it in a way that the user can pick multiple products.
EDIT:
I also have an admin class that goes like this:
public class Admin {
private Client[] clientList;
public AdminPedidos() {
clientList = new Client[2];
}
public void AddContact() {
clienteList[0] = addProduct();
clienteList[1] = addProduct();
fillList();
}
public Cliente addProduct() {
String contactoString = JOptionPane.showInputDialog("Are you a new client? Press 1 if yes.");
if (contactoString.equals("1")) {
return new Cliente();
} else {
return new Cliente(); //just for testing
}
}
private void fillList() {
for (Client i : clientList) {
i.addNewClient();
}
}
public void printContact() {
for (Client i : clientList) {
System.out.println(i.printInfo());
}
}
}

You can have some purchaseProduct method attached to each Client.
public void purchaseProduct(Product product) { this.products.add(product); }
Then each Client you instantiate (Client client = new Client(name, id);) can add Products to his/her cart with the purchaseProduct method.
I'm assuming you are using some kind of user input method (Scanner). With that you can read the user's input of which Product they want and accordingly call the function with the right Product.
The listBuilder function doesn't quite make sense to me btw (and after your edit, it's really hard to make sense of what the Admin class should be/represent).
Edit: You would probably want to create an ArrayList<Product> which will be attached to each client, which you already have. I sense that you have a difficulty deciding where to put your actual Products. You should not put them inside your Client class for sure.
You should think about who/where they are going to be used. Probably in main right? So just instantiate them there first and then the Client could choose which one to purchase (via the method I introduced before):
client.purchaseProduct(product);

Using information from object selected in jList

I am having difficulty getting information from a jList so that it can be used to create an object in a different class when a button is clicked,
private void jButtonAddOrderActionPerformed(java.awt.event.ActionEvent evt) {
int noCopies;
String title, Name;
noCopies = Integer.parseInt(jTextFieldCopies.getText());
title = Book.bookInstances.get(jListPubBooks.getSelectedIndex()).getName();
Name = Book.bookInstances.get(jListPubBooks.getSelectedIndex()).getPublisherName();
new Order(noCopies, title, Name);
setjlistmodel(Order.orderItem);
I am sure there are no problems with my setjlistmodel method as this works elsewhere in my program when only getting information from text fields. I think my problem is with these two lines:
title = Book.bookInstances.get(jListPubBooks.getSelectedIndex()).getName();
Name = Book.bookInstances.get(jListPubBooks.getSelectedIndex()).getPublisherName();
}
This is my order class;
package bookstore;
import java.util.ArrayList;
public class Order {
int noOfBooks;
String bookTitle;
String pubName;
public static ArrayList<Order> orderItem = new ArrayList<>();
ArrayList<ArrayList<Order>> Order = new ArrayList<>();
public Order(int noBooks, String Title, String Name)
{
this.noOfBooks = noBooks;
this.bookTitle = Title;
this.pubName = Name;
orderItem.add(this);
}
public void addOrder(ArrayList ord)
{
Order.add(ord);
}
public int getNoBooks()
{
return noOfBooks;
}
public String getBookTitle()
{
return bookTitle;
}
public String getPubName()
{
return pubName;
}
}
setjlistmodel method:
private void setjlistmodel(ArrayList<Order> orderInstances){
DefaultListModel OrderList = new DefaultListModel();
for(int i = 0; i<=OrderList.size()-1;i++){
OrderList.addElement(orderInstances.get(i).getNoBooks());
System.out.println(orderInstances.get(i).getBookTitle());
System.out.println(OrderList.firstElement());
}
jListOrder.setModel(OrderList);
}
The problem is that it is not displaying anything in jListOrder when the button is clicked. I don't think the Order is being added to the orderItem ArrayList.

"The problem is that it is not displaying anything in jListOrder when the button is clicked. I don't think the Order is being added to the orderItem ArrayList."
I think adding an orderItem is fine.
OrderList size is zero when you first initialize it, which means your loops does absolutely nothing
DefaultListModel OrderList = new DefaultListModel();
for(int i = 0; i <= OrderList.size() - 1; i++)
You probably want
for(int i = 0; i <= orderInstances.size() - 1; i++)
Which is using the ArrayList size.
As a side note, please separate operators with space. It makes it easier to read.