This is my assignment:
Here are my questions:
Exception in thread "main" java.lang.NumberFormatException: empty String at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1012) at java.lang.Double.parseDouble(Double.java:527) at extracredit.Main.readData(Main.java:72) at extracredit.Main.main(Main.java:27)
Here's my code so far:
import java.io.*;
import javax.swing.JOptionPane;
import java.util.*;
import java.util.StringTokenizer;
public class Main {
public static void main(String[] args) throws IOException {
String fname = "data.txt"; //Read in the data file for use in the array
String pass= JOptionPane.showInputDialog("Please enter the " +
"password to continue:"); /*Have the user enter the password to
access the file. */
checkPass(pass); // Verify that the password is correct before continuing.
readData (fname); // Read data, print output and save output file.
}
private static void checkPass (String pass)
{
String password= "INF260";
int passCount= 0;
if (pass.equals(password)) {
System.out.println("The password is correct. Continuing...");
}
else {
do {
pass= JOptionPane.showInputDialog("Please re-enter the" +
"password:");
passCount++;
} while (!pass.equals(password) && passCount < 2);
if (!pass.equals(password)) {
System.out.println("You have tried to enter the " +
"password too many times. Exiting...");
System.exit(0);
}
else {
System.out.println("The password is correct. Continuing...");
}
}
}
public static void readData (String data) throws IOException{
FileReader inputData= new FileReader (data);
BufferedReader findNum= new BufferedReader (inputData);
String str= findNum.readLine ();
int count=-1;
int countNum= 0;
double total= 0;
double min= 0;
double max= 0;
double average= 0;
FileWriter writeFile = new FileWriter("sales.txt");
PrintWriter printFile = new PrintWriter(writeFile);
while (str != null)
{
double num= Double.parseDouble (str);
if (count == 0){
countNum++; // counter of Reciepts to use
}
str = findNum.readLine();
}
double [][] input = new double [countNum][10];
total= getCurrentTotal(input); /*This will get the total
from the method getCurrentTotal.*/
min= getCurrentMin(input); /*This will get the minimum value from
the method getCurrentMin.*/
max= getCurrentMax (input); /*This will get the maximum value from
the method getCurrentMax.*/
average= (total / countNum); //Calculate the average.
System.out.println("The List of Today's Sales:");
for (int row = 0; row < input.length; row++){
System.out.println ();
System.out.println("Customer " + row + "\t");
for (int column = 0; column < input[row].length; column++){
if (input [row].length < 10){
System.out.println(input[row][column] + "\t");
str = findNum.readLine();
}
else{
System.out.println ("There are too many receipts" +
" for one Customer.\n");
System.exit (0);
}
}
}
System.out.println ("There are " + countNum + "receipts in the list.");
/*This will print the total of receipts in the list.*/
System.out.println ("The total of today's sales is $" + total); /*
This will print the total of the sales for the day.*/
System.out.println ("The average of today's sales is $" + average); /*
This will print the average sale total.*/
System.out.println ("The highest receipt is $" + max); /* This will print
the highest sale.*/
System.out.println ("The lowest receipt is $" + min); /* This will print
the lowest sale.*/
Date date = new Date();
System.out.println ("\n The current time is:" + date.toString()); /* This
will print the current date and time */
}
public static double getCurrentTotal (double [][] input){
double totalAmount = 0;
for (int row = 0; row < input.length; row++){
for (int column = 0; column < input [row].length; column++){
totalAmount += input [row][column];
}
}
return totalAmount;
}
public static double getCurrentMin (double [][] input) {
double currentMin = input[0][0];
for (int row = 0; row < input.length; row++){
for (int column = 0; column < input [row].length; column++){
if (currentMin > input[row][column])
currentMin = input[row][column];
}
}
return currentMin;
}
public static double getCurrentMax (double [][] input){
double currentMax = input[0][0];
for (int row = 0; row < input.length; row++){
for (int column = 0; column < input [row].length; column++){
if (currentMax < input[row][column]){
currentMax = input[row][column];
}
}
}
return currentMax;
}
}
The best solution is:
// from your main method
String fname = "data.txt";
readData (fname);
// the method being called
public static void readData (String data[][]){
BufferedReader br = new BufferedReader(new FileReader(data));
We have an incompatibility here.
All of these three should be the same data type.
How can I separate each "receipt" with zero (like shown in the image link above)?
You don't have to. You have to READ from that file with the zeros in it.
I would recommend you write a method something like this:
public double[] readOneReceipt(BufferedReader reader);
This method should
How can I write the output into a separate file?
With a java.io.FileWriter
The hardest bit of this IMO is the fact that you are told to store the data in a 2d array, but you don't exactly what size to make the array until you've read the data. Which means that you either use a temporary dynamic structure, or read the file twice - once to find out how many receipts there are so that you can make the array, and then again to actually read the receipt data.
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.