Creating Strings while Reading a CSV ( Java)

Question

I'am Scanning a CSV File with the following Code:

public void scanFile() {
    boolean isNumber = false;
    String test;

    try {
        sc = new Scanner(Gui.selectedFile);
        sc.useDelimiter("[;\"]");


        while (sc.hasNext() && isNumber == false) {

            test = sc.next();
                if(test.equals("{9}")) {
                    System.out.println("success");
                }


            System.out.println();;
            if (sc.hasNextInt()) {
                isNumber = true;
            }
        } sc.close();

    } catch (Exception e) {
        System.out.println("error");
    }

Now i need a way, to create a String for EACH entry in the CSV. There are around 60 entry's in my CSV. I need to use the read data further in the program.

Why not put them into an array of strings?

dimwittedanimal
– dimwittedanimal

2018-03-20 15:14:00 +00:00
Commented Mar 20, 2018 at 15:14 — dimwittedanimal
– dimwittedanimal, Commented Mar 20, 2018 at 15:14

VHS · Accepted Answer · 2018-03-20 15:24:17Z

1

You can do it the following way with just 3 lines of code:

List<List<String>> data = new ArrayList<List<String>>();
List<String> lines = Files.lines(Paths.get(file)).collect(Collectors.toList());
lines.stream().forEach(s -> data.add(Arrays.asList(s.split(","))));

Here's what it does. The second line above reads all the lines from the CSV file. In the third line, we stream through all the lines (one line at a time) and split the line with a comma as a separator. This split gives us an array of cells in that line. We just convert the array to a list and add it to our datastructure data which is a list of lists.

Later, say, if you want to access the value of 7th cell in the 4th row of the CSV, all you have to do is following:

String cell = data.get(3).get(6);

edited Mar 20, 2018 at 15:24

answered Mar 20, 2018 at 15:15

VHS

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2 Comments

user7261540 Over a year ago

Can you explain me what you did? Thank you!

VHS Over a year ago

@ErwinIvanov, I put some explanation. See if it helps.

CryptoMonkey · Accepted Answer · 2018-03-20 15:17:36Z

0

public ArrayList<String> scanFile() {
boolean isNumber = false;
String test;
ArrayList<String> output = new ArrayList<String>();

try {
    sc = new Scanner(Gui.selectedFile);
    sc.useDelimiter("[;\"]");


    while (sc.hasNext() && isNumber == false) {

        test = sc.next();
             output.add( test );

            if(test.equals("{9}")) {
                System.out.println("success");
            }


        System.out.println();;
        if (sc.hasNextInt()) {
            isNumber = true;
        }
    } sc.close();

} catch (Exception e) {
    System.out.println("error");
}

return output;
}

answered Mar 20, 2018 at 15:17

CryptoMonkey

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2 Comments

user7261540 Over a year ago

How can i access a entry in the arrayList ?

CryptoMonkey Over a year ago

Use the get() method of the arraylist. get( 5) will return the fifth element of the ArrayList.

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