I have a GUI based e-store project. I read in a file and parse through it and saved it into an array.
The file format is like so: 11111, "title", 9.90
11111 is the book id, "title" is title, and 9.90 is the price.
I currently have 3 classes in my project. 1 class for Input/Output, 1 class for the Book store GUI code, and another for pop-up boxes when specific buttons are clicked.
In the GUI code, I check read the file into String[] fileArray and then loop through it until there is a match (with TextField input String bookIds = bookIdinput.getText())
I'm able to successfully get a match and go on with the rest of the code, but when there isn't a match, I get an error: Exception in thread "JavaFX Application Thread" java.lang.NullPointerException at windowDisplay.lambda$start$3(windowDisplay.java:###)
which is this line of code for(int i=0; i<fileArray.length; i++)
If there isn't a match, then it should show a pop-up box saying that bookID isn't found.
Below is some of the GUI code
public class windowDisplay extends Application
{
// Variable declarations
private String[] fileArray = null;
private String holdStr = "";
private Stage mainWindow;
private boolean matchFound = false;
private int count = 1;
private int lineItems = 1;
private double totalAmount = 0.0;
private double subTotal = 0.0;
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) throws Exception
{
// OMITTED CODE
// These TextFields show the output depending on the input TextField's.
itemInfoOutput.setDisable(true);
orderSubtotalOutput.setDisable(true);
// Process item button.
processItem.setText("Process Item #" + count);
processItem.setMinWidth(106);
processItem.setOnAction(e ->
{
int numItems = Integer.parseInt(numItemInput.getText());
lineItems = numItems;
String bookIDs = bookIdInput.getText();
int qtyItems = Integer.parseInt(qtyItemInput.getText());
// Read file and check for Book ID
fileArray = bookStoreIO.readFile(bookIDs);
// Loop through array to find match or no matches
for(int i=0; i<fileArray.length; i++)
{
// If there is a match in book ID
if (fileArray[i].equals(bookIDs))
{
double price = Double.parseDouble(fileArray[i + 2]); // Price is in the i+2 position
double discount = calculateDiscount(qtyItems);
totalAmount = calculatePrice(qtyItems, price);
itemInfoOutput.setText(fileArray[i] + " " + fileArray[i + 1] + " " + "$" + price + " " +
qtyItems + " " + discount + "%" + " " + "$" + df.format(totalAmount));
// Disable processItem Button if there is a match and enable confirmItem Button
processItem.setDisable(true);
confirmItem.setDisable(false);
matchFound = true;
}
}
if(matchFound == false)
System.out.println("No match found!");
});
}
// OMITTED CODE
// This method calculates the discount depending on the quantity of items
public static double calculateDiscount(int inputQty){return null;}
// This methdod calculates the price with the discount
public static double calculatePrice(int inputQty, double price){return null;}
}
This class reads the file and returns an array with the contents of that file (once split by the ", " delimitter).
public class bookStoreIO
{
// This method reads the input file "inventory.txt" and saves it into an array.
public static String[] readFile(String stringIn)
{
try
{
String nextLine;
String[] fIn;
// Read file
BufferedReader br = new BufferedReader(new FileReader("inventory.txt"));
while((nextLine = br.readLine()) != null)
{
fIn = nextLine.split(", "); // Split when ", " is seen
if(stringIn.equalsIgnoreCase(fIn[0]))
{
br.close(); // Close file
return fIn; // Return array
}
}
}
// Just in case file isn't found
catch(IOException e)
{
System.out.println("File not found.");
}
return null;
}
I apologize if this seems messy, I'm still new to JavaFX and Java programming.
If you think more code is needed, please let me know!
EDIT: I improved some variable naming and removed the for loop. I'm still having trouble checking when there isn't a match.
public class windowDisplay extends Application
{
// Variable declarations
private String[] fileArray = null;
private Stage mainWindow;
private boolean matchFound = false;
private int count = 1;
private int lineItems = 1;
private double totalAmount = 0.0;
private double subTotal = 0.0;
private int itemQty = 0;
private int idBook = 0;
private String bookTitle = "";
private double bookPrice = 0.0;
private double discountAmount = 0.0;
private String resultOrder = "";
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) throws Exception
{
// OMITTED CODE
// These TextFields show the output depending on the input TextField's.
itemInfoOutput.setDisable(true);
orderSubtotalOutput.setDisable(true);
// Process item button.
processItem.setText("Process Item #" + count);
processItem.setMinWidth(106);
processItem.setOnAction(e ->
{
int numItems = Integer.parseInt(numItemInput.getText());
lineItems = numItems;
String bookIDs = bookIdInput.getText();
itemQty = Integer.parseInt(qtyItemInput.getText());
// Read file and check for Book ID
fileArray = bookStoreIO.readFile(bookIDs);
idBook = Integer.parseInt(fileArray[0]);
bookTitle = fileArray[1];
bookPrice = Double.parseDouble(fileArray[2]);
discountAmount = calculateDiscount(itemQty);
totalAmount = calculatePrice(itemQty, bookPrice);
itemInfoOutput.setText(idBook + " " + bookTitle + " $" + bookPrice + " " + itemQty + " " + discountAmount
+ "% $" + df.format(totalAmount));
itemInfo.setText("Item #" + count + " info:");
processItem.setDisable(true);
confirmItem.setDisable(false);
matchFound = true;
if(matchFound == false)
System.out.println("not found");
});
// OMITTED CODE
// This method calculates the discount depending on the quantity of items
public static double calculateDiscount(int inputQty){return null;}
// This method calculates the price with the discount
public static double calculatePrice(int inputQty, double price){return null;}
}
I'm also having trouble saving
itemInfoOutput.setText(idBook + " " + bookTitle + " $" + bookPrice + " " + itemQty + " " + discountAmount
+ "% $" + df.format(totalAmount));
into an String or String array to print out a list of all the corresponding matches (along with their book ID, book Title, book Price, quantity, discount , and total price).
An example is shown below:
enter image description here
EDIT 2: The right box is the main GUI. The bottom left box is what shows up when a wrong book is entered (on the 2nd order). The top left is the length of the array.
// Process item button.
processItem.setText("Process Item #" + count);
processItem.setMinWidth(106);
processItem.setOnAction(e ->
{
int numItems = Integer.parseInt(numItemInput.getText());
lineItems = numItems;
String bookIDs = bookIdInput.getText();
itemQty = Integer.parseInt(qtyItemInput.getText());
// Read file and check for Book ID
fileArray = bookStoreIO.readFile(bookIDs);
for(int i=0; i<fileArray.length; i++)
System.out.println(fileArray[i]);
if(fileArray.length >= 3)
{
idBook = Integer.parseInt(fileArray[0]);
bookTitle = fileArray[1];
bookPrice = Double.parseDouble(fileArray[2]);
discountAmount = calculateDiscount(itemQty);
totalAmount = calculatePrice(itemQty, bookPrice);
resultOrder = itemInfoOutput.getText();
itemInfoOutput.setText(idBook + " " + bookTitle + " $" + bookPrice + " " + itemQty + " " + discountAmount
+ "% $" + df.format(totalAmount));
resultOrder = idBook + " " + bookTitle + " $" + bookPrice + " " + itemQty + " " + discountAmount
+ "% $" + df.format(totalAmount);
itemInfo.setText("Item #" + count + " info:");
processItem.setDisable(true);
confirmItem.setDisable(false);
}
else
alertBox.confirmDisplay("Book ID " + idBook + " not in file");
});
How do I not store values from the program when it loops back again. For example, if I plan to enter two families, first I will ask for the details of the first family and display their names, and then I want to use the same variables to collect the next family and display their names without having stored information from the previous family.
public static void main(String[] args) {
// TODO code application logic here
String ans;
String res;
double cont;
int cot;
String name;
String order = "";
do {
ans = JOptionPane.showInputDialog(null,"What is the name of the "
+ "family?" );
res = JOptionPane.showInputDialog(null, "How many member in the " + ans +
" family?");
cot = Integer.parseInt(res); // Converts res String to a number
for (int count = 1; count < cot; count ++) {
name = JOptionPane.showInputDialog(null, " Enter first name: " + count);
order += name + " " + ans + "\n";
}
JOptionPane.showMessageDialog(null, "Members of the " + ans
+ " Family" + "\n" + order);
cont = JOptionPane.showConfirmDialog(null, "Do you want to add another "
+ "family", "Membership", JOptionPane.YES_NO_OPTION);
}while (cont == JOptionPane.YES_OPTION);
if (cont == JOptionPane.NO_OPTION){
JOptionPane.showMessageDialog(null," Come Back Again");
}
}
}
Your order variable is a String that you are adding the names to. Just reset it at the beginning of the loop:
...
do {
order = "";
...
I have an array it has (id,name,salary)
I want to search specific ID using Employee search method, my code is:
Employee SearchID(int i_d) {
for (int i = 0; i < staff.length; i++) {
boolean check = true;
if (staff[i].id == i_d) {
System.out.println("Id: " + staff[i].id + ", name: " + staff[i].name + " and salary: " + staff[i].salary);
} else {
System.out.println("Sorry, no record exists with record id = " + i_d);
}
}
return staff[i].id;
}
Your SearchID method returns an Employee object but you return a primitive type. (staff[i].id) You must change return type of your method.
You can fix your method like this:
Employee SearchID(int i_d) {
for (int i = 0; i < staff.length; i++) {
if (staff[i].id == i_d) {
System.out.println("Id: " + staff[i].id + ", name: " + staff[i].name + " and salary: " + staff[i].salary);
return staff[i];
}
}
System.out.println("Sorry, no record exists with record id = " + i_d);
return null;
}
And, of course, you need to handle the null result after calling SearchID properly.
Okay so now I got my code to compile and run, but the output is incorrect now. I need to be able to select an option and then for 2, and 3 have 3 additional options after selecting that option. How should I adapt my coding to do this?
Task:
List of all information
List of all surgeries for a specific doctor (prompt for the doctor)
List of all surgeries of a specific type (prompt for the surgery type)
Total amount of surgery fees paid to each Doctor
Average Fees
Data File (patient.txt):
11111,Smith,Norris,Thyroid,1000.00
11112,Obama,Norris,Lasek,500.00
11113,Hoover,Norris,Dental,100.00
11114,Cena,Norris,Lasek,500.00
11115,Leto,Norris,Thyroid,1000.00
22221,Clark,Bond,Thyroid,1000.00
22222,Chang,Bond,Lasek,500.00
22223,Dent,Bond,Dental,100.00
22224,Nixon,Bond,Lasek,500.00
22225,Washington,Bond,Dental,100.00
33331,Jones,Lee,Dental,100.00
33332,Ross,Lee,Lasek,500.00
33333,Gates,Lee,Thyroid,1000.00
33334,Johnson,Lee,Thyroid,1000.00
33335,Carter,Lee,Dental,100.00
Code so far for reference:
package Patient_Reports_Package;
/**
* Created by bzink on 8/28/2015.
*/
import javax.swing.*;
import java.io.*;
import java.util.StringTokenizer;
/**
* The Patient_Reports_File class reads the data file into an array, and then has a menu for 5 reports.
*/
class Patient_Reports {
private final int[] id = new int[100];
private final String[] patient = new String[100];
private final String[] doctor = new String[100];
private final String[] surgery = new String[100];
private final double[] cost = new double[100];
private int count = -1;
private int i;
public static void main (String[] args) {
int selection;
String report_number;
Patient_Reports patient = new Patient_Reports();
patient.start_system();
report_number = patient.menu();
selection = Integer.parseInt(report_number);
while (selection !=6) {
if (selection == 1) {
patient.allInformationReport();
} else if (selection == 2) {
patient.surgeryDoctorReport();
} else if (selection == 3) {
patient.surgeryTypeReport();
} else if (selection == 4) {
patient.doctorFeesReport();
} else if (selection == 5) {
patient.averageFeesReport();
}
report_number = patient.menu();
selection = Integer.parseInt(report_number);
}//while loop
patient.writeReports();
System.exit(0);
}//main
//Read Data File into Array
private void start_system() {
String newLine;
try {
//define a file variable for Buffered read
BufferedReader Patient_Reports = new BufferedReader(new java.io.FileReader("C:\\Users\\Brandon\\" +
"Downloads\\Patient_Reports_File\\patient.txt"));
//read lines in file until there are no more lines in the file to read
while ((newLine = Patient_Reports.readLine()) != null) {
//there is a "," between each data item in each line
StringTokenizer delimiter = new StringTokenizer(newLine, ",");
count = count + 1;
id[count] = Integer.parseInt(delimiter.nextToken());
patient[count] = delimiter.nextToken();
doctor[count] = delimiter.nextToken();
surgery[count] = delimiter.nextToken();
cost[count] = Double.parseDouble(delimiter.nextToken());
}//while loop
Patient_Reports.close();
}//end try
catch (IOException error) {
//there was an error on the file writing
System.out.println("Error on file read " + error);
}//end catch
}//end start_system
//Report Menu
private String menu () {
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append("Id ").append(" \n");
stringBuilder.append("Patient ").append(" \n");
stringBuilder.append("Doctor ").append(" \n");
stringBuilder.append("Surgery ").append(" \n");
stringBuilder.append("Cost ").append(" \n");
for (int i = 0; i < 6; i++) {
stringBuilder.append(i).append(" Name"+i).append('\n');
}
String startTag ="<font size='2' color='red'>";
String endTag = "</font>";
stringBuilder.append(startTag).append("Some content").append(endTag);
JOptionPane.showMessageDialog(null, stringBuilder.toString());
return stringBuilder.toString();
}//end menu\
/*
//Report Menu
private String menu() {
String report;
String Output = "Reports" + "\n" + "1. All_Information_Report" + "\n" +
"2. Surgeries_Doctor_Report" + "\n" +
"3. Surgeries_Type_Report" + "\n" +
"4. Doctor_Fees_Report" + "\n" +
"5. Average_Fees_Report" + "\n" +
"6. Exit" + "\n" +
" " + "\n" +
"Select a Report >";
report = JOptionPane.showInputDialog(null,
Output, "", JOptionPane.QUESTION_MESSAGE);
return report;
}//end menu\
*/
//Report containing all of the information
private void allInformationReport() {
System.out.println("All Information Report");
for (i = 0; i <= count; ++i) {
System.out.println(id[i] + " " + patient[i] + " " + doctor[i] + " " + surgery[i] + " " + cost[i] + " ");
}//for loop
}//end report
/* void selectDoctor()
{
//select doctor
String doctorOutput;
//int intNum=0,intNum1=0,i,x=-1;
count=count+1;
doctorOutput = "Enter the Doctor's Name";
doctor[count] =JOptionPane.showInputDialog(null,doctorOutput,
"",JOptionPane.QUESTION_MESSAGE);
}//end select doctor
//Start Doctor Menu
public static void doctorMenu (String[] args) {
int selection;
String doctorName;
Patient_Reports doctor = new Patient_Reports();
doctor.start_system();
doctorName = doctorMenu();
selection = Integer.parseInt(doctorName);
while (selection !=4) {
if (selection == 1) {
doctor.norrisSurgeries();
} else if (selection == 2) {
doctor.bondSurgeries();
} else if (selection == 3) {
doctor.leeSurgeries();
}
doctorName = doctorMenu();
selection = Integer.parseInt(doctorName);
}//while loop
doctor.writeReports();
System.exit(0);
}//End Doctor Menu
//Report on all surgeries by Dr. Norris
private void norrisSurgeries() {
System.out.println("Norris Surgeries Report");
for (i = 0; i <= count; ++i) {
System.out.println(doctor[i] + " " + surgery[i] + " ");
}//for loop
}//end report
//Report on all surgeries by Dr. Bond
private void bondSurgeries() {
System.out.println("Bond Surgeries Report");
for (i = 0; i <= count; ++i) {
System.out.println(doctor[i] + " " + surgery[i] + " ");
}//for loop
}//end report
//Report on all surgeries by Dr. Lee
private void leeSurgeries() {
System.out.println("Lee Surgeries Report");
for (i = 0; i <= count; ++i) {
System.out.println(doctor[i] + " " + surgery[i] + " ");
}//for loop
}//end report
*/
//Report on all surgeries of a specific doctor (prompt for the doctor)
private void surgeryDoctorReport() {
System.out.println("Surgeries Doctor Report");
for (i = 0; i <= count; ++i) {
System.out.println(id[i] + " " + patient[i] + " " + doctor[i] + " " + surgery[i] + " " + cost[i] + " ");
}//for loop
}//end report
/*
void selectSurgery()
{
//select surgery
String surgeryOutput;
//int intNum=0,intNum1=0,i,x=-1;
count=count+1;
surgeryOutput = "Enter the Surgery Type";
doctor[count] =JOptionPane.showInputDialog(null,surgeryOutput,
"",JOptionPane.QUESTION_MESSAGE);
}//end select surgery
*/
//Report on all surgeries of a specific type(Prompt for the surgery type)
private void surgeryTypeReport() {
System.out.println("Surgeries Type Report");
for (i = 0; i <= count; ++i) {
System.out.println(id[i] + " " + patient[i] + " " + doctor[i] + " " + surgery[i] + " " + cost[i] + " ");
}//for loop
}//end report
//Report on the total amount of fees paid to each doctor
private void doctorFeesReport() {
System.out.println("Doctor Fees Report");
for (i = 0; i <= count; ++i) {
System.out.println(id[i] + " " + patient[i] + " " + doctor[i] + " " + surgery[i] + " " + cost[i] + " ");
}//for loop
}//end report
//Report on the Average Fee
private void averageFeesReport() {
System.out.println("Average Fees Report");
for (i = 0; i <= count; ++i) {
System.out.println(id[i] + " " + patient[i] + " " + doctor[i] + " " + surgery[i] + " " + cost[i] + " ");
}//for loop
}//end report
//Store Data File in Array
private void writeReports()
{
try {
BufferedWriter Patient_Reports = new BufferedWriter(new java.io.FileWriter("patient_out.txt"));
for (i = 0; i <= count; ++i) {
//put "," between each data item in the file
Patient_Reports.write(id[i] + "," + patient[i] + "," + doctor[i] + "," +
surgery[i] + "," + cost[i] + ",");
//write a new line in the file
Patient_Reports.newLine();
}//for loop
Patient_Reports.close();
}//end try
catch (IOException error) {
//there was an error on the write to file
System.out.println("Error on file write " + error);
}//end error
}//end write_reports
}
'
Use String or StringBuilder or StringBuffer to do this. But instead of String use either StringBuilder or StringBuffer. Since for String, you need some extra objects for String manipulation.
Ex:
StringBuilder sb = new StringBuilder();
sb.append("Id ").append(" Name\n");
for (int i = 0; i < 10; i++) {
sb.append(i).append(" Name"+i).append('\n');
}
JOptionPane.showMessageDialog(null, sb.toString());
Use HTML tags to produce better formatted results like <font>, <table>, etc.
Ex:
String startTag ="<font size='2' color='red'>";
String endTag = "</font>";
sb.append(startTag+"Some content"+endTag);
In my code below, I am having an issue where I add the customer name to one room, but instead it adds the customer to every room. I can't figure out what in my code the issue is. I have tried removing the procedure but that still produced the same problem.
package test;
import java.util.*;
public class test {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
String choice, custName = "";
int roomNum = 1;
String[] hotel = new String[12];
String[] customer = new String[12];
hotelInitialise(hotel);
custInitialise(customer);
while ( roomNum < hotel.length-1 ) {
for (int i = 0; i < hotel.length-1; i++) {
System.out.println("This is the Hotel Menu. Please choose from the following options:\n");
System.out.println("A: " + "This will add a new entry\n");
System.out.println("V: " + "View all rooms\n");
choice = input.next().toUpperCase();
if (choice.equals("A")) {
System.out.println("Enter room number(1-10)");
roomNum =input.nextInt();
System.out.println("Enter name for room " + roomNum + " : " ) ;
custName = input.next();
addNewBooking(hotel, custName);
System.out.println(" ");
}
if (choice.equals("V")) {
seeAllRooms(hotel, custName);
}
}
}
}
// When the program loads it will assign all the values of the array as being empty
private static void hotelInitialise( String hotelRef[] ) {
for (int x = 0; x < 11; x++){
hotelRef[x] = "Room " + x + " is empty.";
}
System.out.println( "Welcome to the Summer Tropic Hotel.\n");
}
private static void custInitialise (String custRef[]) {
for (int i = 0; i < 11; i++) {
custRef[i] = ", no customer has occupied this room";
}
}
private static void addNewBooking(String hotel[], String customer) {
for (int x =1; x <11; x++) {
if (hotel[x].equals("Room " + hotel[x] + " is empty."))
System.out.println("Room " + x + " is empty.");
else {
System.out.println("Room " + x + " is occupied by "+ customer);
}
}
}
private static void seeAllRooms(String hotel[], String customer) {
for (int i = 0; i < hotel.length-1; i++) {
int j=0;
String custName = customer;
hotel[j]= custName;
if (hotel[i].equals("Room " + i + " is empty."))
System.out.println("Room " + i + " is empty.");
else {
System.out.println("Room " + i + " is occupied by "+ hotel[j] + ".");
}
}
}
}
In addNewBooking method you have this line:
if (hotel[x].equals("Room " + hotel[x] + " is empty."))
However hotel[x] has a value of "Room x is empty" e.g. hotel[1] is "Room 1 is empty" So the final check is becoming "hotel[x].equals(Room Room x is empty is empty.)" which is never equals to your hotel[x]
You have to change your code to
if (hotel[x].equals("Room " + x + " is empty."))
//do something there like add the booking