We Keep Coding

Return more that one ArrayList

I'm trying to deal with this baking JSON:
in android app so this is the class to bring the JSON data from link:
OpenBakingJsonUtils.java:
public final class OpenBakingJsonUtils {
public static ArrayList<ArraysLists> getSimpleBakingStringsFromJson(Context context, String bakingJsonString)
throws JSONException {
final String ID = "id";
final String NAME = "name";
final String SERVINGS = "servings";
final String INGREDIENTS = "ingredients";
final String STEPS = "steps";
final String QUANTITY = "quantity";
final String MEASURE = "measure";
final String INGREDIENT = "ingredient";
final String IDSTEPS = "id";
final String SHORTDESCRIPTION = "shortDescription";
final String DESCRIPTION = "description";
final String VIDEOURL = "videoURL";
final String THUMBNAILURL = "thumbnailURL";
ArrayList<ArraysLists> parsedRecipeData = new ArrayList<ArraysLists>();
ArrayList<BakingItem> Baking = new ArrayList<BakingItem>();
JSONArray recipeArray = new JSONArray(bakingJsonString);
for (int i = 0; i < recipeArray.length(); i++) {
int id;
String name;
int servings;
double quantity;
String measure;
String ingredient;
int idSteps;
String shortDescription;
String description;
String videoURL;
String thumbnailURL;
JSONObject recipeObject = recipeArray.getJSONObject(i);
id = recipeObject.getInt(ID);
name = recipeObject.getString(NAME);
servings = recipeObject.getInt(SERVINGS);
ArrayList<IngredientsItem> Ingredients = new ArrayList<IngredientsItem>();
JSONArray ingredientsArray = recipeObject.getJSONArray(INGREDIENTS);
for(int j = 0 ; j< ingredientsArray.length(); j++) {
JSONObject ingredientsObject = ingredientsArray.getJSONObject(j);
quantity = ingredientsObject.getDouble(QUANTITY);
measure = ingredientsObject.getString(MEASURE);
ingredient = ingredientsObject.getString(INGREDIENT);
Ingredients.add(new IngredientsItem(quantity, measure, ingredient));
}
ArrayList<StepsItem> Steps = new ArrayList<StepsItem>();
JSONArray stepsArray = recipeObject.getJSONArray(STEPS);
for(int j = 0 ; j< stepsArray.length(); j++) {
JSONObject stepsObject = stepsArray.getJSONObject(j);
idSteps = recipeObject.getInt(IDSTEPS);
shortDescription = stepsObject.getString(SHORTDESCRIPTION);
description = stepsObject.getString(DESCRIPTION);
videoURL = stepsObject.getString(VIDEOURL);
thumbnailURL = stepsObject.getString(THUMBNAILURL);
Steps.add(new StepsItem(idSteps, shortDescription, description, videoURL, thumbnailURL));
}
Baking.add(new BakingItem(id, name, servings, Ingredients, Steps));
parsedRecipeData.add(new ArraysLists(Baking, Ingredients, Steps));
}
return parsedRecipeData;
}
}
as you see there are 3 ArrayList classes:
ArrayList<BakingItem>
ArrayList<IngredientsItem>
ArrayList<StepsItem>
and this is the code for each one:
BakingItem.java:
public class BakingItem implements Parcelable {
private int id;
private String name;
private int servings;
private ArrayList<IngredientsItem> ingredients = new ArrayList<IngredientsItem>();
private ArrayList<StepsItem> steps = new ArrayList<StepsItem>();
public BakingItem(int id, String name, int servings, ArrayList<IngredientsItem> ingredients, ArrayList<StepsItem> steps) {
this.id = id;
this.name = name;
this.servings = servings;
this.ingredients = ingredients;
this.steps = steps;
}
#Override
public void writeToParcel(Parcel out, int flags) {
out.writeInt(id);
out.writeString(name);
out.writeInt(servings);
out.writeTypedList(ingredients);
out.writeTypedList(steps);
}
private BakingItem(Parcel in) {
this.id = in.readInt();
this.name = in.readString();
this.servings = in.readInt();
ingredients = new ArrayList<IngredientsItem>();
in.readTypedList(ingredients, IngredientsItem.CREATOR);
}
public BakingItem() {
}
#Override
public int describeContents() {
return 0;
}
public static final Parcelable.Creator<BakingItem> CREATOR = new Parcelable.Creator<BakingItem>() {
#Override
public BakingItem createFromParcel(Parcel in) {
return new BakingItem(in);
}
#Override
public BakingItem[] newArray(int i) {
return new BakingItem[i];
}
};
public int getId() {
return id;
}
public String getName() {
return name;
}
public int getServings() {
return servings;
}
}
IngredientsItem.java:
public class IngredientsItem implements Parcelable {
private double quantity;
private String measure;
private String ingredient;
public IngredientsItem(double quantity, String measure, String ingredient) {
this.quantity = quantity;
this.measure = measure;
this.ingredient = ingredient;
}
#Override
public void writeToParcel(Parcel out, int flags) {
out.writeDouble(quantity);
out.writeString(measure);
out.writeString(ingredient);
}
private IngredientsItem(Parcel in) {
this.quantity = in.readDouble();
this.measure = in.readString();
this.ingredient = in.readString();
}
public IngredientsItem() {
}
#Override
public int describeContents() {
return 0;
}
public static final Parcelable.Creator<IngredientsItem> CREATOR = new Parcelable.Creator<IngredientsItem>() {
#Override
public IngredientsItem createFromParcel(Parcel in) {
return new IngredientsItem(in);
}
#Override
public IngredientsItem[] newArray(int i) {
return new IngredientsItem[i];
}
};
public double getQuantity() {
return quantity;
}
public String getMeasure() {
return measure;
}
public String getIngredient() {
return ingredient;
}
}
as well as the StepsItem class
and the forth is the ArraysLists.java which contain all the 3 arrays above and returned by the OpenBakingJsonUtils.java:
Then I'm trying to call these JSON data in different activities
so in MainActivity.java in loadInBackground:
Override
public ArrayList<BakingItem> loadInBackground() {
URL recipeRequestUrl = NetworkUtils.buildUrl();
try {
String jsonBakingResponse = NetworkUtils.getResponseFromHttpUrl(recipeRequestUrl);
ArrayList<ArraysLists> simpleJsonBakingData = OpenBakingJsonUtils.getSimpleBakingStringsFromJson(MainActivity.this, jsonBakingResponse);
return simpleJsonBakingData;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
I call the returned ArrayList from OpenBakingJsonUtils.java which is in this case the ArraysLists,
then in DetailActivity.java in doInBackground:
#Override
protected ArrayList<ArraysLists> doInBackground(Object... params) {
if (params.length == 0) {
return null;
}
URL reviewsRequestUrl = NetworkUtils.buildUrl();
try {
String jsonReviewResponse = NetworkUtils.getResponseFromHttpUrl(reviewsRequestUrl);
ArrayList<ArraysLists> simpleJsonReviewData = OpenBakingJsonUtils.getSimpleBakingStringsFromJson(DetailsActivity.this, jsonReviewResponse);
return simpleJsonReviewData;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
here I call the ArrayList of ArraysLists too but the problem in adapters of MainActivity.java and DetailsActivity.java in onBindViewHolder:
holder.CommentContent.setText(String.valueOf(mCommentsItems.get(position).getQuantity()));
it just says that cannot resolve method getQuantity() which is in IngredientsItem.java while I used the ArraysLists.java that returned by OpenBakingJsonUtils.java
so what should I do to call methods from BakingItem.java and IngredientsItem.java while I use the returned ArraysLists.java ?

Adding information into an array with super classes

The problem I'm having is with the superclass. I can't change the new Property(...) to another class called House. The only difference is the information in them, but once I change it I am getting an error stating that the constructor doesn't match but I thought that the super() should pass the information on.
This is how my Array is set up:
public static void main(String[] args) {
Property [] Properties = new Property[25];
Properties[0] = new Property (1001, 200, "58 Lackagh Park", "Dungiven", "BT47 4ND", new MyDate(15,05,2018), 5000.00, 800.50, 40.50);
Properties[1] = new Property (1002, 500, "24 Jop Lane", "Kelflar", "VT57 5LP", new MyDate(10,06,2018), 12000.00, 1000.00, 60.00);
Properties[2] = new Property (1003, 100, "Lot B", "Bandlebop", "LU49 3JU", new MyDate(01,07,2018), 450.00, 800.00, 50.50);
Properties[3] = new Property (1004, 200, "12 Back Lane", "Galafray", "GA1 1Fy", new MyDate(05,12,2018), 50000.00, 1000.00, 80.00);
Properties[4] = new Property (1005, 200, "43 Pop Street", "Jundar", "BY78 1JH", new MyDate(11,12,2018), 2500.00, 600.50, 32.90);
Properties[5] = new Property (1006, 200, "123 Fake Street", "Dunlem", "BL09 4PL", new MyDate(21,03,2018), 65000.00, 700.50, 56.50);
Properties[6] = new Property (1007, 200, "09012 Bakers Field", "Bristol", "LO87 D0N", new MyDate(15,05,2018), 5000.00, 200.50, 40.50);
Properties[7] = new Property (1008, 200, "Unit B high Street", "LA", "LA58 7NL", new MyDate(18,11,2018), 20000.00, 1000.00, 90.00);
Properties[8] = new Property (1009, 200, "1 Flabbergast Park", "Nubb", "HJ98 7NH", new MyDate(10,03,2018), 4958.00, 900.20, 20.50);
Properties[9] = new Property (1010, 200, "29 Bakers Field", "London Town", "HU84 2JO", new MyDate(02,05,2018), 1234.00, 800.00, 40.50);
Properties[10] = new Property (1011, 200, "20 Peliper Lane", "Dungiven", "BT47 4FE", new MyDate(15,05,2018), 4321.00, 900.00, 20.00);
Here is the Property class:
public class Property {
private int PropertyNumber, SquareFoot;
private String Address,Town,PostCode;
private MyDate DateListed;
public double Price;
private double Rates;
private double PricePerSquareFoot;
public Property() {
PropertyNumber = 0;
SquareFoot = 0;
Address = "";
Town = "";
PostCode = "";
DateListed = new MyDate();
Price = 0.0;
Rates = 0.0;
PricePerSquareFoot = 0.0;
}
public Property(int PropertyNumber, int SquareFoot, String Address, String Town, String PostCode, MyDate DateListed, double Price, double rates, double PricePerSquareFoot)
{
super();
this.PropertyNumber = PropertyNumber;
this.SquareFoot = SquareFoot;
this.Address = Address;
this.Town = Town;
this.PostCode = PostCode;
this.DateListed = DateListed;
this.Price = Price;
this.Rates = Rates;
this.PricePerSquareFoot = PricePerSquareFoot;
}
//--------Getters and setters----------------//
public void setPropertyNumber(int PropertyNumber)
{
this.PropertyNumber = PropertyNumber;
}
public int getPropertyNumber()
{
return PropertyNumber;
}
public void setSquareFoot(int SquareFoot)
{
this.SquareFoot = SquareFoot;
}
public int getSquareFoot()
{
return SquareFoot;
}
public void setAddress(String Address)
{
this.Address = Address;
}
public String getAddress()
{
return Address;
}
public void setTown( String Town)
{
this.Town = Town;
}
public String getTown()
{
return Town;
}
public void setPostcode( String PostCode)
{
this.PostCode = PostCode;
}
public String GetPostcode()
{
return PostCode;
}
public void setDateListed(MyDate DateListed)
{
this.DateListed = DateListed;
}
public MyDate getDateListed()
{
return DateListed;
}
public void setPrice(double Price)
{
this.Price = Price;
}
public double getPrice()
{
return Price;
}
public void setRates(double Rates)
{
this.Rates = Rates;
}
public double getRates()
{
return Rates;
}
public void setPricePerSquareFoot(double PricePerSqaureFoot)
{
this.PricePerSquareFoot = PricePerSquareFoot;
}
public double getPricePerSquareFoot()
{
return PricePerSquareFoot;
}
And this is what I am trying to put into the array along with the property information such as Property number price etc:
public class House extends Residential {
private int Garden;
private int Garage;
public House() {
super();
Garage = 0;
Garden = 0;
}
public House(int Garage, int garden) {
super();
this.Garage = 0;
this.Garden = 0;
}
public void setGarage(int Garage)
{
this.Garage = Garage;
}
public int getGarage()
{
return Garage;
}
public void setGarden(int Garden)
{
this.Garden = Garden;
}
public int getGarden()
{
return Garden;
}
.......
This is the residential class
public class Residential extends Property
{
private int NumberOfBedrooms;
private int NumberOfBathrooms;
public Residential()
{
super();
NumberOfBedrooms = 0;
NumberOfBathrooms = 0;
}
public void setNumberOfBedrooms(int NumberOfBedrooms)
{
this.NumberOfBedrooms = NumberOfBedrooms;
}
public int getNumberOfBedrooms()
{
return NumberOfBedrooms;
}
public void setNumberOfBathrooms(int NumberOfBathrooms)
{
this.NumberOfBathrooms = NumberOfBathrooms;
}
public int getNumberOfBathrooms()
{
return NumberOfBathrooms;
}
public Residential(int NumberOfBedrooms, int NumberOfBathrooms)
{
super();
NumberOfBedrooms = 0;
NumberOfBathrooms = 0;
}

Created add() method to insert objects into an array and all i get are null values

this is a class called Doglist to add the object to an array.
public class DogList {
private int numItems;
private DogItem[] dogListArray;
private int position;
DogList () {
numItems=0;
position = 0;
dogListArray = new DogItem[10];
}
public void add (DogItem item) {
dogListArray[numItems++]= new DogItem(item.getName(),
item.getBreed(),
item.getWeight(),
item.getOwner1(),
item.getOwner2()
);
}
public String toString() {
String result = "";
for (int i=0; i<numItems; i++) {
result += dogListArray[i].toString() + "\n";
}
return result;
}
public DogItem searchForDogItem (DogItem gi) {
System.out.println("Here is your obj value: " + gi );
return null;
}//This is the one im having trouble with.
}
I have all the setters and getters in the DogItem class.
and this is from the UI where i get the dog info(name, breed, weight, owners1&2 names)
public void searchForItem (String name ) {
DogItem gi = new DogItem (name);
gi = gl.searchForDogItem(gi);
if (gi==null) {
msgTextField.setText("Dog Not Found");
} else {
nameTextField.setText(String.valueOf(gi.getName()));
breedTextField.setText(String.valueOf(gi.getBreed()));
weightTextField.setText(String.valueOf(gi.getWeight()));
owner1TextField.setText(String.valueOf(gi.getOwner1()));
owner2TextField.setText(String.valueOf(gi.getOwner2()));
}
}
Ill try and clear things up as i go.
this is the output i get
Here is your obj value: null null 0.0 null null

Ok so here is what it probably should look like instead. Just from what I saw wrong already. However you'd probably want to override the toString() method of DogItem.
Main method example of this:
public class Main {
public static void main(String[] args) {
DogItem dogItem = new DogItem("Spot", "Dalmation", "45", "Bob", "Sandy");
DogItem.add(dogItem);
DogItem result = DogItem.searchForItem("Spot");
if (result == null) {
System.out.println("Dog not found");
// GUI error output goes here
} else {
System.out.println("Here is your obj value: " + result);
// Where your GUI stuff goes
}
}
}
DogItem example of this:
public class DogItem {
private static DogItem[] dogListArray = new DogItem[100];
private static int numItems = 0;
private String name;
private String breed;
private String weight;
private String owner1;
private String owner2;
public DogItem(String name, String breed, String weight, String owner1, String owner2) {
this.name = name;
this.breed = breed;
this.weight = weight;
this.owner1 = owner1;
this.owner2 = owner2;
}
public static void add(DogItem dogItem) {
dogListArray[numItems++] = dogItem;
}
public static DogItem searchForItem(String name) {
DogItem dogItem = null;
for (DogItem result : dogListArray) {
if (result != null) {
if (result.getName() == name) {
dogItem = result;
}
}
}
return dogItem;
}
#Override
public String toString() {
String result = name + ", " + breed + ", " + weight + ", " + owner1 + " " + owner2;
return result;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getBreed() {
return breed;
}
public void setBreed(String breed) {
this.breed = breed;
}
public String getWeight() {
return weight;
}
public void setWeight(String weight) {
this.weight = weight;
}
public String getOwner1() {
return owner1;
}
public void setOwner1(String owner1) {
this.owner1 = owner1;
}
public String getOwner2() {
return owner2;
}
public void setOwner2(String owner2) {
this.owner2 = owner2;
}
}
These would be recommended changes from me though:
private static ArrayList<String> owners;
private static ArrayList<DogItem> dogsList;
public DogItem(String name, String breed, String weight, String owner) {
this.name = name;
this.breed = breed;
this.weight = weight;
this.owners.add(owner);
}
public void init() {
owners = new ArrayList<String>();
dogsList = new ArrayList<DogItem>();
}
public void addDog(DogItem dogItem) {
dogsList.add(dogItem);
}
public DogItem searchForItem(String name) {
DogItem dogItem = null;
for (DogItem result : dogsList) {
if (result != null) {
if (result.getName() == name) {
dogItem = result;
}
}
}
return dogItem;
}
public void addOwner(String owner) {
owners.add(owner);
}
public String getOwner() {
return owners.get(owners.size() - 1);
}

Making a class-array dynamic in Java

I've created a Java class called 'Book'. Using this class I'm willing to update information about a new object 'book1'. I'm also wanting to add Author information into the object 'book1'. So, I've dynamically allocated memory using a class-array called 'Author[ ]'. By this I mean there's a separate code in which I've created a class called 'Author' with its own set of instance variables. I'm not getting into that now. However, when I'm testing the class 'Book' using another class called 'TestBook' there's no compilation error BUT I'm getting the following message in the console window when I'm running the code:
Exception in thread "main" java.lang.NullPointerException
at Book.addAuthors(Book.java:34)
at TestBook.main(TestBook.java:12)
The code for 'Book' is shown below:
public class Book {
private String name;
private Author[] A = new Author[];
private int numAuthors = 0;
private double price;
private int qtyInStock;
public Book(String n, Author[] authors, double p) {
name = n;
A = authors;
price = p;
}
public Book(String n, Author[] authors, double p, int qIS) {
name = n;
A = authors;
price = p;
qtyInStock = qIS;
}
public Book(String n, double p, int qIS) {
name = n;
price = p;
qtyInStock = qIS;
}
public String getName() {
return name;
}
/*
public Author getAuthors() {
return A;
}
*/
public void addAuthors(Author newAuthor) {
A[numAuthors] = newAuthor; // THIS LINE IS WHERE THE ERROR POINTS TO
++numAuthors;
}
public void printAuthors() {
/*
for (int i = 0; i < A.length; i++) {
System.out.println(A[i]);
}
*/
for (int i = 0; i < numAuthors; i++) {
System.out.println(A[i]);
}
}
public void setPrice(double p) {
price = p;
}
public double getPrice() {
return price;
}
public void setqtyInStock(int qIS) {
qtyInStock = qIS;
}
public int getqtyInStock() {
return qtyInStock;
}
/*
public String getAuthorName() {
return A.getName();
}
public String getAuthorEmail() {
return A.getEmail();
}
public char getAuthorGender() {
return A.getGender();
}
*/
public String toString() {
/*
return getName() + " " + getAuthor() + " Book price: " + getPrice() +
" Qty left in stock: " + getqtyInStock();
*/
//return getName() + " is written by " + A.length + " authors.";
return getName() + " is written by " + numAuthors + " authors.";
}
}
The code for 'TestBook' is shown below:
public class TestBook {
public static void main(String args[]) {
//Author[] authors = new Author[2];
//authors[0] = new Author("Tapasvi Dumdam Thapashki", "tapasvi#thapashki.com", 'M');
//authors[1] = new Author("Paul Rand", "paulie#aol.com", 'M');
Book book1 = new Book("The Quickie Man", 69.00, 5);
//System.out.println(book1.toString());
//book1.setqtyInStock(5);
//System.out.println(book1.toString());
//System.out.println(book1.getAuthorName() + " " + book1.getAuthorEmail());
//book1.printAuthors();
book1.addAuthors(new Author("Linda Lee", "lindalee#grinchtown.com", 'F'));
book1.addAuthors(new Author("Joseph Caputo", "caputo#lfp.com", 'M'));
System.out.println(book1.toString());
book1.printAuthors();
}
}
The code for 'Author' is shown below:
public class Author {
private String name;
private String email;
private char gender;
public Author(String n, String e, char g) {
name = n;
email = e;
gender = g;
}
public String getName() {
return name;
}
public void setEmail(String e) {
email = e;
}
public String getEmail() {
return email;
}
public char getGender() {
return gender;
}
public String toString() {
return getName() + " [" + getGender() + "] " + getEmail();
}
}
I'd like some help with this.

Initialize Author array with proper size like private Author[] A = new Author[4];

You forgot to specify the size of the Array.
private Author[] A = new Author[15];
For making a dynamic array you can use ArrayList.
private ArrayList<Author> list = new ArrayList<Author>();
addAuthors()
public void addAuthors(Author newAuthor) {
list.add(newAuthor);
}
printAuthors()
public void printAuthors() {
for (int i = 0; i < list.size(); i++) {
System.out.println(list.get(i));
}
}

Interface references

I'm not sure how to address this question. Here is my code:
public interface Stuff {
public String description();
public double weight();
}
class Bag implements Stuff {
public String description() {
return "bag of";
}
public double weight() {
return 10.50;
}
}
class StuffWrapper implements Stuff {
Stuff item;
public StuffWrapper(Stuff item) {
this.item = item;
}
public String description() {
return item.description();
}
public double weight() {
return item.weight();
}
}
class Material extends StuffWrapper {
String material;
double weight;
public Material(Stuff item, String material, double weight) {
super(item);
this.material = material;
this.weight = weight;
}
public String description() {
return item.description() + " :" + material+ ":";
}
public double weight() {
return item.weight() + weight;
}
}
and then I have this:
Stuff icStuff = new Bag();
icStuff = new Material(icStuff, "leather", 10.30);
icStuff = new Material(icStuff, "plastic", 20.50);
System.out.println(icStuff.description() + Double.toString(icStuff.weight()));
which outputs
bag of :leather: :plastic:41.3
After doing all of that if I wanted icStuff to no longer reference this:
icStuff = new Material(icStuff, "plastic", 20.50);
How should I do it?

assign it to something else, or null, or whatever you want it to reference
icStuff = null;
icStuff = Somethingelse;