Is their an easy way to pass the variables and arrays between these methods without having a super long method signature? Currently I am using these statics but I know that's not the "correct" way of doing it but if I pass them in the signature it starts to make everything look ugly. So what would be the "correct" way to pass the variables like lastName, firstName, and role?
// Program wide variables
//static String firstName; // First name from the file
static String lastName; // Last name from the file
static String username; // Username
static String password;
static String role;
static String email;
static String answersFile; // Answers file in use with path and ext
static String[] answeredQ = new String[questAsks]; // Recording the question asked
static Boolean[] answeredA = new Boolean[questAsks]; //Recording users answer
static Boolean[] answeredC = new Boolean[questAsks]; //Recording the correct answer
public static void main(String Args[]) throws FileNotFoundException, IOException {
// Main method that contains major control functions; a quick summary of the program; magic
}
public static void quiz(String testType) throws HeadlessException, IOException {
String testBankFile = path + testType + ".txt";
Random rand = new Random();
int questionCount = 0, right = 0, wrong = 0;
long startTime = System.currentTimeMillis(); // Setting the start time in milliseconds
while (questionCount < questAsks) { // Loop that will ask all the questions
int r = rand.nextInt(getLines(testBankFile));
boolean ans = promptQuestion(read(r, testBankFile), questionCount + 1); // For some reason this makes it work
answeredQ[questionCount] = read(r, testBankFile);
answeredA[questionCount] = ans;
answeredC[questionCount] = parseA(read(r, answersFile));
if (ans != parseA(read(r, answersFile))) {
wrong++;
} else if (ans == parseA(read(r, answersFile))) {
right++;
}
questionCount++;
}
JOptionPane.showMessageDialog(null, "You got " + wrong + " wrong and " + right + " correct.");
long endDiff = (System.currentTimeMillis() - startTime);
makeReport(firstName, lastName, username, printTime(endDiff), testType, right);
}
// Generates a report report(first, last, score, time, array of answers)
public static void makeReport(String first, String last, String user, String time, String testType, int score) throws IOException {
DateFormat dateF = new SimpleDateFormat(dateFormat);
Date date = new Date();
String fileName = user + "_COSC236_Quiz_" + dateF.format(date) + ".txt";
File file = new File(fileName);
file.createNewFile();
FileWriter out = new FileWriter(fileName);
double percent = (((double) score) / ((double) questAsks) * 100);
out.write("Name: " + first + " " + last + "\n");
out.write("Score: " + percent + "%\n");
out.write("Elapsed time: " + time + "\n");
out.write("Test type: " + testType + "\n");
out.write("---------------------------------------------------------------------\n");
out.write(" Users\tCorrect\tQuestion\n");
for (int i = 0; i < answeredQ.length; i++) {
out.write(i + 1 + ".) ");
out.write(answeredA[i].toString() + "\t");
out.write(answeredC[i].toString() + "\t");
out.write(answeredQ[i] + "\n");
}
out.close();
}
// Boolean login method | login(tries allowed, source file)
public static void login(int tries, String source) throws FileNotFoundException, IOException {
String[] loginInfo;
boolean invalid = false;
for (int x = 0; x < tries; x++) {
invalid = false;
loginInfo = promptLogin();
if (loginInfo[0].toLowerCase().equals("done")) {
System.exit(0);
}
for (int i = 0; i < getLines(source); i++) {
StringTokenizer st = null;
st = new StringTokenizer(read(i, source));
String user = st.nextToken();
String pass = st.nextToken();
if (user.equals(loginInfo[0])) {
if (pass.equals(loginInfo[1])) {
username = loginInfo[0];
password = loginInfo[1];
firstName = st.nextToken();
lastName = st.nextToken();
email = st.nextToken();
role = st.nextToken();
if (role.toLowerCase().equals("instructor")) {
promptInstructor();
JOptionPane.showMessageDialog(null, exitedInstructorMode);
break;
} else {
run();
}
} else {
invalid = true;
}
} else {
invalid = true;
}
}
if(invalid) {
JOptionPane.showMessageDialog(null, invalidLogin);
}
}
JOptionPane.showMessageDialog(null, tooManyAttempts);
}
}
Why not just make a class that holds the values that you need to pass around
Use OOP. Create clss to you object
example:
class User{
String lastName;
String username;
String password;
String role;
String email;
...
public static User login(int tries, String source) throws FileNotFoundException, IOException {
//this you read User param and add new User
return user;
}
}
And now, where you need lastName, username, password, role or email, you can
pass User instance
Related
I am working on a piece of code that is supposed to move elements of a class array (users) to a new array (ordered) if the user's "ordered" parameter is set as Y. The code will work for a few users, but for most it just skips over them. Why is this? Am I comparing the strings wrong or is there something else that I am not aware of?
System.out.println("List of ordered phones:");
for(int i = 0; i < users.length; i++) {
if(users[i].ordered.equals("Y")) {
ordered[i] = users[i];
System.out.println(ordered[i].name);
}
}
This is the loop in question. There isn't much to it other than the string comparison but even that is pretty straight forward.
Here is the entire program:
class User{
String name;
String phoneNum;
String current;
String type;
String requested;
String location;
String ordered;
User(String name, String phoneNum, String current, String type, String requested, String location, String ordered){
this.name = name;
this.phoneNum = phoneNum;
this.current = current;
this.type = type;
this.requested = requested;
this.location = location;
this.ordered = ordered;
}
public User() {
}
}
public class readWrite {
#SuppressWarnings("unlikely-arg-type")
public static void main(String[] args) throws FileNotFoundException {
User[] users = new User[149];
User[] ordered = new User[149];
User[] received = new User[149];
User[] trade = new User[149];
int count = 0;
File file = new File("I don't like showing my file path but it's correct");
Scanner scan = new Scanner(file);
while(scan.hasNextLine()) {
User user = new User(scan.nextLine(), scan.nextLine(), scan.nextLine(), scan.nextLine(), scan.nextLine(), scan.nextLine(), scan.nextLine());
users[count] = user;
count++;
}
User temp;
for(int i = 0; i < users.length; i++) {
for(int j = 0; j < users.length; j++) {
if(users[i].name.charAt(0) < users[j].name.charAt(0)) {
temp = users[i];
users[i] = users[j];
users[j] = temp;
}
}
}
for(int i = 0; i < users.length; i++) {
System.out.println(i + "." + " Name: " + users[i].name + "\n" + "Phone Number: " + users[i].phoneNum + "\n" + "Current Phone: " + users[i].current + "\n" + "Phone Type: " + users[i].type + "\n" + "Requested Phone: " + users[i].requested + "\n" + "Location: " + users[i].location + "\n" + "Ordered?: " + users[i].ordered + "\n\n");
}
System.out.println("List of ordered phones:");
for(int i = 0; i < users.length; i++) {
if(users[i].ordered.equals("Y")) {
ordered[i] = users[i];
System.out.println(ordered[i].name);
}
}
Is it possible that they're skipped because they do not meet the following condition?
if(users[i].ordered.equals("Y"))
I figured it out. In the 3 for loops, instead of i, I needed to use "ord","rec", and "traded" so that no null entries go into the filtered arrays. When I was using i as the index it was inserting null values because i always grows even if the condition isn't met.
I am trying to read an input file. Each value of the input file is inserted into the TreeMap as
If word is not existing: Insert the word to the treemap and associate the word with an ArrayList(docId, Count).
If the Word is present in the TreeMap, then check if the current DocID matches within the ArrayList and then increase the count.
THe
For the ArrayList, I created another class as below:
public class CountPerDocument
{
private final String documentId;
private final int count;
CountPerDocument(String documentId, int count)
{
this.documentId = documentId;
this.count = count;
}
public String getDocumentId()
{
return this.documentId;
}
public int getCount()
{
return this.count;
}
}
After that, I am trying to print the TreeMap into a text file as <DocID - Count>
Not sure what I am doing wrong here, but the output I get is as follows:
The Stem is todai:[CountPerDocument#5caf905d, CountPerDocument#27716f4, CountPerDocument#8efb846, CountPerDocument#2a84aee7, CountPerDocument#a09ee92, CountPerDocument#30f39991]
Wondering if anyone can guide me what i am doing wrong and if my method isn't correct what am i supposed to do?
public class StemTreeMap
{
private static final String r1 = "\\$DOC";
private static final String r2 = "\\$TITLE";
private static final String r3 = "\\$TEXT";
private static Pattern p1,p2,p3;
private static Matcher m1,m2,m3;
public static void main(String[] args)
{
BufferedReader rd,rd1;
String docid = null;
String id;
int tf = 0;
//CountPerDocument cp = new CountPerDocument(docid, count);
List<CountPerDocument> ls = new ArrayList<>();
Map<String,List<CountPerDocument>> mp = new TreeMap<>();
try
{
rd = new BufferedReader(new FileReader(args[0]));
rd1= new BufferedReader(new FileReader(args[0]));
int docCount = 0;
String line = rd.readLine();
p1 = Pattern.compile(r1);
p2 = Pattern.compile(r2);
p3 = Pattern.compile(r3);
while(line != null)
{
m1 = p1.matcher(line);
m2 = p2.matcher(line);
m3 = p3.matcher(line);
if(m1.find())
{
docid = line.substring(5, line.length());
docCount++;
//System.out.println("The Document ID is :");
//System.out.println(docid);
line = rd.readLine();
}
if(m2.find()||m3.find())
{
line = rd.readLine();
}
else
{
if(!(mp.containsKey(line))) // if the stem is not on the TreeMap
{
//System.out.println("The stem is not present in the tree");
tf = 1;
ls.add(new CountPerDocument(docid,tf));
mp.put(line, ls);
line = rd.readLine();
}
else
{
if(ls.indexOf(docid) > 0) //if its last entry matches the current document number
{
//System.out.println("The Stem is present for the same docid so incrementing docid");
tf = tf+1;
ls.add(new CountPerDocument(docid,tf));
line = rd.readLine();
}
else
{
//System.out.println("Stem is present but not the same docid so inserting new docid");
tf = 1;
ls.add(new CountPerDocument(docid,tf)); //set did to the current document number and tf to 1
line = rd.readLine();
}
}
}
}
rd.close();
System.out.println("The Number of Documents in the file is:"+ docCount);
//Write to an output file
String l = rd1.readLine();
File f = new File("dictionary.txt");
if (f.createNewFile())
{
System.out.println("File created: " + f.getName());
}
else
{
System.out.println("File already exists.");
Path path = Paths.get("dictionary.txt");
Files.deleteIfExists(path);
System.out.println("Deleted Existing File:: Creating New File");
f.createNewFile();
}
FileWriter fw = new FileWriter("dictionary.txt");
fw.write("The Total Number of Stems: " + mp.size() +"\n");
fw.close();
System.out.println("The Stem is todai:" + mp.get("todai"));
}catch(IOException e)
{
e.printStackTrace();
}
}
}
You didn't define the function String toString() in your class CountPerDocument. So, when you try to print a CountPerDocument variable, the default printed value is CountPerDocument#hashcode.
To decide how to represent a CountPerDocument variable in your code, add in your class the next function:
#Override
public String toString() {
return "<" + this.getDocumentId() + ", " + this.getCount() + ">";
}
Try to override toString method in CountPerDocument. Something like this:
public class CountPerDocument
{
private final String documentId;
private final int count;
CountPerDocument(String documentId, int count)
{
this.documentId = documentId;
this.count = count;
}
public String getDocumentId()
{
return this.documentId;
}
public int getCount()
{
return this.count;
}
#Override
public String toString() {
return documentId + "-" + count;
}
}
import java.util.Random;
import java.util.StringTokenizer;
public class FortuneCookie {
private String subjList;
private String objList;
private String verbList;
private int sWords = 0;
private int oWords = 0;
private int vWords = 0;
private Random random = new Random();
public FortuneCookie() {
subjList = "i#You#He#She#It#They";
objList = "me#you#him#her#it#them";
verbList = "hate#love#deny#find#hear#forgive#hurt#win#teach";
}
public void setSubject(String subj) {
subjList = subj;
}
public void setObjectList(String obj) {
objList = obj;
}
public void setVerbList(String verb) {
verbList = verb;
}
public String genFortuneMsg() {
String v = " ";
String o = " ";
String s = " ";
StringTokenizer st1 = new StringTokenizer(subjList, "#");
StringTokenizer st2 = new StringTokenizer(objList, "#");
StringTokenizer st3 = new StringTokenizer(verbList, "#");
while (st1.hasMoreTokens()) {
s = st1.nextToken();
sWords = st1.countTokens();
int no = random.nextInt(sWords);
if (no == sWords) {
break;
}
}
while (st2.hasMoreTokens()) {
o = st2.nextToken();
oWords = st2.countTokens();
int no2 = random.nextInt(oWords);
if (no2 == oWords) {
break;
}
}
while (st3.hasMoreTokens()) {
v = st3.nextToken();
vWords = st3.countTokens();
int no3 = random.nextInt(vWords);
if (no3 == vWords) {
break;
}
}
String gen = s + " " + v + " " + o;
return gen;
}
public void print() {
System.out.println("Tokens");
System.out.println("Subject List:" + subjList + " count = " + sWords);
System.out.println("verb List:" + verbList + " count = " + vWords);
System.out.println("object List:" + objList + " count = " + oWords);
}
}
Exception in thread "main" java.lang.IllegalArgumentException: bound
must be positive at java.util.Random.nextInt(Random.java:388) at
FortuneCookie.genFortuneMsg(FortuneCookie.java:42) at
FortuneCookieTest.main(FortuneCookieTest.java:6)
Your case is not negative it is zero.
From the docs of countToken method
/**
* Calculates the number of times that this tokenizer's
* <code>nextToken</code> method can be called before it generates an
* exception. The current position is not advanced.
*
In a while loop when your count token return zero, you run into an exception. Well that error message should be reformatted to negative or zero.
Add 1 to your result or check for zero. Should work.
So I want to read a text file but for some strange reason it can't find the file. I have used these methods before, and I therefore have no idea why this isn't working can someone please help me out?
EDIT:
sorry guys I left out a big piece of info which is that it can find the file when it is writing to it but not when it is reading from it. Thanks for all your guys' help and sorry for wasting your time asking a question I didn't need the answer to... Again sorry.
Some more info:
"Assets.txt" is in both the project's root folder as well as in the src/assetregistry
"Assets.txt" will be there when the program is run
All I get is the JOption messege from the catch exception in the readFromFile() method
According to the properties of assetRegistry the working directory is
"C:\Users\Justin\Documents\NetBeansProjects\assetregistry\src\assetregistry"
Thank you to everyone who helped, especially Chris and Andrew Thompson. The program now work and the following is the updated version. Feel free to copy it if you want. It's really a simple program.
Main class:
package assetregistry;
import java.io.IOException;
import javax.swing.JOptionPane;
public class Assetregistry {
public static void main(String[] args) throws IOException {
new Assetregistry();
}
assetArray aa = new assetArray();
public Assetregistry() throws IOException {
aa.readFromFile ();
char choice = 'Z';
while (choice != 'X') {
choice = menu();
options(choice);
}
}
public char menu() {
char ch = JOptionPane.showInputDialog("\t" + "Welcome to asset registry. Please input your choice" + "\n" + "A: Enter new asset" + "\n" + "B: Calculate depreciation and display" + "\n" + "X: Exit").toUpperCase().charAt(0);
return ch;
}
private void options(char c) throws IOException {
switch (c) {
case 'A':
aa.enterAsset();
break;
case 'B':
aa.calculate();
break;
case 'X':
System.exit(0);
break;
}
}
}
Array/method class
package assetregistry;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import javax.swing.JOptionPane;
public class assetArray {
asset[] aArr = new asset[100];
private double year;
private double month;
private int count = 0;
Assetregistry AR;
String home = System.getProperty("user.home");
File userHome = new File(home);
File file = new File(userHome,"Assets.txt");
public assetArray() throws IOException {
}
public void enterAsset() throws IOException {
int choice = JOptionPane.YES_OPTION;
while (choice == JOptionPane.YES_OPTION) {
String name = JOptionPane.showInputDialog("Enter asset name");
double costP = Double.parseDouble(JOptionPane.showInputDialog("Enter the cost price of the asset"));
int lSpan = Integer.parseInt(JOptionPane.showInputDialog("Enter the amount of years you wish to keep the asset"));
double mBought = Double.parseDouble(JOptionPane.showInputDialog("Enter the month the asset was bought (As a number)"));
double yBought = Double.parseDouble(JOptionPane.showInputDialog("Enter the year the asset was bought"));
double depr = (1.00 / lSpan * 100.00);
aArr[count] = new asset(name, costP, lSpan, yBought, mBought, depr);
PrintWriter pw = new PrintWriter(new FileWriter(file, true));
pw.println(aArr[count].toString());
pw.close();
count++;
choice = JOptionPane.showConfirmDialog(null, " Do you want to enter another asset?", " Enter another asset?", JOptionPane.YES_NO_OPTION);
}
}
public void calculate() {
String name;
int lSpan;
double ybought;
double mbought;
double pValue;
double Rate;
double deprExp;
double numYears;
double fValue;
double accDepr;
String[] mnth = new String[12];
mnth[0] = "January";
mnth[1] = "February";
mnth[2] = "March";
mnth[3] = "April";
mnth[4] = "May";
mnth[5] = "June";
mnth[6] = "July";
mnth[7] = "August";
mnth[8] = "September";
mnth[9] = "October";
mnth[10] = "November";
mnth[11] = "December";
if (count > 0) {
year = Integer.parseInt(JOptionPane.showInputDialog("Enter the year you wish to calculate depreciation for"));
month = Integer.parseInt(JOptionPane.showInputDialog("Enter the month you wish to calculate depreciation for"));
int m = (int) month;
int y = (int) year;
System.out.println("Asset regestry" + "\t" + mnth[m-1] + " " + y);
for (int i = 0; i < count; i++) {
name = aArr[i].getName();
lSpan = aArr[i].getLifeSpan();
ybought = aArr[i].getyBought();
mbought = aArr[i].getmBought();
pValue = aArr[i].getCostP();
Rate = aArr[i].getDeprR();
int m2 = (int) mbought;
int y2 = (int) ybought;
deprExp = pValue - (pValue * ((1.00 - ((Rate))) * 1.00 / 100.00));
numYears = (year + (month / 12.00)) - (ybought + mbought / 12.00);
fValue = pValue * (1.00 - (((Rate) * (numYears)) / 100.00));
if (fValue <= 0.00) {
fValue = (int) 1;
}
accDepr = pValue - fValue;
System.out.println("\n" + "Asset: " + name);
System.out.println("Life span: " + lSpan + "yrs");
System.out.println("Cost price: " + "R" + pValue);
System.out.println("Date acquired: " + mnth[m2-1] + " " + y2);
System.out.println("Depreciatin rate (p.a.): " + Rate + "%");
System.out.println("Depreciation(p.a.): R" + deprExp);
System.out.println("Accumulated depreciation: R" + accDepr);
System.out.println("Current book value: R" + fValue);
System.out.println("_________________________________________");
}
} else {
JOptionPane.showMessageDialog(null, "There are no assets in memory", "NO ASSETS!", JOptionPane.ERROR_MESSAGE);
}
}
/**
*
*/
public void readFromFile() {
String line = "";
try {
BufferedReader fr = new BufferedReader(new FileReader(file));
line = fr.readLine();
while (line != null) {
StringTokenizer stk = new StringTokenizer(line, "#");
String name = stk.nextToken();
double costP = Double.parseDouble(stk.nextToken());
int lSpan = Integer.parseInt(stk.nextToken());
double yBought = Double.parseDouble(stk.nextToken());
double mBought = Double.parseDouble(stk.nextToken());
double deprR = Double.parseDouble(stk.nextToken());
aArr[count] = new asset(name, costP, lSpan, yBought, mBought, deprR);
count++;
line = fr.readLine();
}
fr.close();
} catch (Exception e) {
JOptionPane.showMessageDialog(null, "There is a file missing.", "FILE MISSING!", JOptionPane.ERROR_MESSAGE);
}
}
}
Assets class
package assetregistry;
/**
*
* #author Justin
*/
public class asset {
private String name;
private double costP;
private int lifeSpan;
private double yBought;
private double mBought;
private double deprR;
public asset(){
}
public asset(String name, double costP, int lifeSpan, double yBought, double mBought, double deprR) {
this.name = name;
this.costP = costP;
this.lifeSpan = lifeSpan;
this.yBought = yBought;
this.mBought = mBought;
this.deprR = deprR;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getCostP() {
return costP;
}
public void setCostP(double costP) {
this.costP = costP;
}
public int getLifeSpan() {
return lifeSpan;
}
public void setLifeSpan(int lifeSpan) {
this.lifeSpan = lifeSpan;
}
public double getyBought() {
return yBought;
}
public void setyBought(double yBought) {
this.yBought = yBought;
}
public double getmBought() {
return mBought;
}
public void setmBought(double mBought) {
this.mBought = mBought;
}
public double getDeprR() {
return deprR;
}
public void setDeprR(double deprR) {
this.deprR = deprR;
}
#Override
public String toString ()
{
String stg = "";
stg += name + "#" + costP + "#" + lifeSpan + "#" + yBought + "#" + mBought + "#" + deprR + "#";
return stg;
}
}
String home = System.getProperty("user.home");
System.out.println("User home directory is: " + home);
File userHome = new File(home);
// Put files in a known and reproducible path!
File file = new File(userHome, "Assets.txt");
It depends where you have put "Assets.txt" in your file system. If you are running the code from inside netbeans, then the line:
File file = new File("Assets.txt");
will be looking for the file in the root folder of your project e.g. */NetBeansProjects/INSERT_PROJECT_NAME/ (if you're not then it will be looking for the file in the same directory the application is running in).I noticed you have the line:
URL url = AR.getClass().getResource("/Assets.txt");
but you never use url in your code. Are you trying to look for the file in the same directory as your "Assetregistry" class and forgot to use url to specify the location? If this is the case then remove the "/" from the beginning of the name and construct the file like this:
URL url = Assetregistry.class.getResource("Assets.txt");
File file = new File(url.toURI());
Hope this helps :)
Good day!
I am making a mini bookstore program and we are required to read a file based from what the customer buys on the specified counter as follows:
counter 4,book1 2,book2 2,book3 2,tender 100.00
counter 1,book1 2,book2 1,book3 3, book4 5,tender 200.00
counter 1,book3 1,tender 50.00
In short the format is:
COUNTER -> ITEMS BOUGHT -> TENDER
I tried doing this but it is not that efficient:
public List<String> getOrder(int i) {
List <String> tempQty = new ArrayList<String>();
String[] orders = orderList.get(0).split(",");
for (String order : orders) {
String[] fields = order.split(" ");
tempQty.add(fields[i]);
}
return tempQty;
}
How can i read the file and at the same time, ensures that I will put it on the correct array? Besides the counter and the tender, I need to know the name of the book and the qty so I could get its price and computer for the total price. Do I need to do multiple arrays to store each values? Any suggestions/ codes will be
highly appreciated.
Thank you.
Map<String, Integer> itemsBought = new HashMap<String, Integer>();
final String COUNTER = "counter";
final String TENDER = "tender";
String[] splitted = s.split(",");
for (String str : splitted) {
str = str.trim();
if (str.startsWith(COUNTER)) {
//do what you want with counter
} else if (str.startsWith(TENDER)) {
//do what you want with tender
} else {
//process items, e.g:
String[] itemInfo = str.split(" ");
itemsBought.put(itemInfo[0], Integer.valueOf(itemInfo[1]));
}
}
How about this? Here we have a class that is modeling a purchase, containing counter, tender and a list of the bought items. The bought item consists of an id (e.g. book1) and a quantity. Use the method readPurchases() to read the contents of a file and get a list of purchases.
Does this solve your problem?
public class Purchase {
private final int counter;
private final List<BoughtItem> boughtItems;
private final double tender;
public Purchase(int counter, List<BoughtItem> boughtItems, double tender) {
this.counter = counter;
this.boughtItems = new ArrayList<BoughtItem>(boughtItems);
this.tender = tender;
}
public int getCounter() {
return counter;
}
public List<BoughtItem> getBoughtItems() {
return boughtItems;
}
public double getTender() {
return tender;
}
}
public class BoughtItem {
private final String id;
private final int quantity;
public BoughtItem(String id, int quantity) {
this.id = id;
this.quantity = quantity;
}
public String getId() {
return id;
}
public int getQuantity() {
return quantity;
}
}
public class Bookstore {
/**
* Reads purchases from the given file.
*
* #param file The file to read from, never <code>null</code>.
* #return A list of all purchases in the file. If there are no
* purchases in the file, i.e. the file is empty, an empty list
* is returned
* #throws IOException If the file cannot be read or does not contain
* correct data.
*/
public List<Purchase> readPurchases(File file) throws IOException {
List<Purchase> purchases = new ArrayList<Purchase>();
BufferedReader lines = new BufferedReader(new FileReader(file));
String line;
for (int lineNum = 0; (line = lines.readLine()) != null; lineNum++) {
String[] fields = line.split(",");
if (fields.length < 2) {
throw new IOException("Line " + lineNum + " of file " + file + " has wrong number of fields");
}
// Read counter field
int counter;
try {
String counterField = fields[0];
counter = Integer.parseInt(counterField.substring(counterField.indexOf(' ') + 1));
} catch (Exception ex) {
throw new IOException("Counter field on line " + lineNum + " of file " + file + " corrupt");
}
// Read tender field
double tender;
try {
String tenderField = fields[fields.length - 1];
tender = Double.parseDouble(tenderField.substring(tenderField.indexOf(' ') + 1));
} catch (Exception ex) {
throw new IOException("Tender field on line " + lineNum + " of file " + file + " corrupt");
}
// Read bought items
List<BoughtItem> boughtItems = new ArrayList<BoughtItem>();
for (int i = 1; i < fields.length - 1; i++) {
String id;
int quantity;
try {
String bookField = fields[i];
id = bookField.substring(0, bookField.indexOf(' '));
quantity = Integer.parseInt(bookField.substring(bookField.indexOf(' ') + 1));
BoughtItem boughtItem = new BoughtItem(id, quantity);
boughtItems.add(boughtItem);
} catch (Exception ex) {
throw new IOException("Cannot read items from line " + lineNum + " of file " + file);
}
}
// We're done with this line!
Purchase purchase = new Purchase(counter, boughtItems, tender);
purchases.add(purchase);
}
return purchases;
}
}