I'm a beginner to programming and I need some help trying to read from a text file into an ArrayList that contains objects of different types. I've created a program that controls an inventory of videos which I currently have hard coded into an ArrayList in the program but I would like to change this so every time the program runs, the program reads from the text file which contains the inventory and converts that into an ArrayList instead of reading from the ArrayList that is already in the program. I've already added a function that writes the inventory to the text file once the program has quit but I can't seem to get it to read from the text file.
The problem I'm having is that my ArrayList (videos) contains (String, String, Character, String). I don't know how to change the code I have so that scanner splits each line in the text file into the appropriate chunks (for title, type, availability and return date) and then inserts each individual chunk into the appropriate place in the ArrayList. I hope that made sense.
I've tried creating a CSV and using the split() function but I couldn't figure out how to use that to insert into an ArrayList as I end up with four strings in a line rather than (String, String, Character, String). I've even tried changing my current ArrayList so that every element is a string but I still wasn't sure how to make that work.
Any help would be really appreciated. Let me know if you need further information.
EDIT: To sum up, my question is: if I have a text file as seen below, how do I split that into 4 lines and then each line into 4 strings (or 3 strings and 1 character) and insert each string into an ArrayList so that I end up with an ArrayList of four InventoryRow's like this: ("Casablanca", "Old", 'Y', null)
Inventory Row Class:
class InventoryRow {
private String name;
private String type;
private Character availability;
private String returndate;
public InventoryRow(String name, String type, Character availability,
String returndate) {
this.name = name;
this.type = type;
this.availability = availability;
this.returndate = returndate;
}
public String getReturndate() {
return returndate;
}
public void setReturndate(String returndate) {
this.returndate = returndate;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public Character getAvailability() {
return availability;
}
public void setAvailability(Character availability) {
this.availability = availability;
}
public String toString() {
return name + " " + type + " " + availability + " " + returndate;
}
}
Main method (including my current code which doesn't work):
public class InventorySort {
public static void main(String[] args) throws ParseException, JSONException, FileNotFoundException {
/*
* List<InventoryRow> videos = new ArrayList<InventoryRow>();
*
* videos.add(new InventoryRow("Casablanca", "Old", 'Y', null));
* videos.add(new InventoryRow("Jurassic Park", "Regular", 'N',
* "31/07/2015")); videos.add(new InventoryRow("2012", "Regular", 'Y',
* null)); videos.add(new InventoryRow("Ant-Man", "New", 'Y', null));
*/
// Get's today's date and adds three to it = return date
Calendar cal = Calendar.getInstance();
SimpleDateFormat dateReturn = new SimpleDateFormat("dd/MM/yyyy", Locale.UK);
cal.add(Calendar.DATE, 3);
Scanner input = new Scanner(System.in);
boolean run = true;
while (run) {
// Read from text file
Scanner s = new Scanner(new File("videos.txt"));
List<InventoryRow> videos = new ArrayList<InventoryRow>();
while (s.hasNext()) {
videos.add(new InventoryRow(s.next(), null, null, null));
}
s.close();
// Output the prompt
System.out.println("Do you want to list, rent, check, return, add, delete or quit?");
// Wait for the user to enter a line of text
String line = input.nextLine();
// List, rent and check functions
// List function
if (line.equals("list")) {
// Sort videos alphabetically
list(videos);
// Rent function
} else if (line.equals("rent")) {
rent(videos, cal, dateReturn, input);
// Check function
} else if (line.equals("check")) {
check(videos, input);
// If anything else is entered
} else if (line.equals("return")) {
returnVideo(videos, input);
} else if (line.equals("add")) {
add(videos, input);
} else if (line.equals("delete")) {
delete(videos, input);
} else if (line.equals("quit")) {
run = false;
writeFile(videos);
} else {
other();
}
}
}
The code I have for writing to the text file:
private static void writeFile(List<InventoryRow> videos) {
String fileName = "videos.txt";
try {
FileWriter fileWriter = new FileWriter(fileName);
BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
for (InventoryRow ir : videos) {
bufferedWriter.write(ir.toString() + System.getProperty("line.separator"));
}
bufferedWriter.close();
} catch (IOException ex) {
System.out.println("Error writing to file '" + fileName + "'");
}
}
My text file looks like this:
2012 Regular Y null
Ant-Man New Y null
Casablanca Old Y null
Jurassic Park Regular N 31/07/2015
Scannerto read 4 times? Or read the whole line and split using 3 spaces for separator