将随机行数的字符串保存到单行数组JAVA

Question

So here is the method which is reading from the file, it then splits the information by the @ sign. which is where a new month begins in the text file

public static String readPurchaseOrder(Scanner sc) {

    final String DELIMITER = "@";
    try {           
        while (sc.hasNext()) {
            sc.useDelimiter(DELIMITER);
            String data = sc.next();               
            return data;
        }

    } catch (Exception e) {
        System.out.println(e);
    }
    sc.close(); 
    return null;
}

The text file contains information shown below up to the 12th month

  04/01/12#PNW-1234#PA/1234#10
    15/01/12#BSE-5566#bT/4674#5@
    08/02/12#PNE-3456#Xk/8536#1@
    07/03/12#PEA-4567#ZR/7413#3
    09/03/12#ESE-6329#HY/7195#30@
    03/04/12#ESE-5577#LR/4992#12
    23/04/12#PNW-1235#HY/7195#2@
    09/05/12#ESE-6329#PV/5732#6
    25/05/12#BSE-5566#PV/5732#10@
    08/06/12#PNE-3457#kD/9767#1
    31/06/12#EMI-6329#ZR/7413#10@
    03/07/12#EMI-6329#PV/5732#12
    25/07/12#BSE-5566#bT/4674#5@

I am using this to output the information from the file split by the @

 for (int i = 0; i <12; i ++){
          String str[] = InputFileData.readPurchaseOrder(sC).split("\\n");
          for(String s : str){
              System.out.println(s);
          }

It outputs the data like this

04/01/12#PNW-1234#PA/1234#10
15/01/12#BSE-5566#bT/4674#5

08/02/12#PNE-3456#Xk/8536#1

07/03/12#PEA-4567#ZR/7413#3
09/03/12#ESE-6329#HY/7195#30

03/04/12#ESE-5577#LR/4992#12
23/04/12#PNW-1235#HY/7195#2

09/05/12#ESE-6329#PV/5732#6
25/05/12#BSE-5566#PV/5732#10

I want to store each individual line in an array, so I can then further split up the line to its each respective variables

Answer 1

If you would like to collect the results in an array, one line per array element, the easiest way to do it is to use a list (since you don't know in advance the number of lines), and then convert it to an array. The size of an array has to be declared in advance, so you want to use a more flexible data structure if you don't know how big it's going to be.

public static String[] readPurchaseOrder(Scanner sc) {
    final String DELIMITER = "@";
        List<String> results = new ArrayList<>();
        try {           
            while (sc.hasNext()) {
                sc.useDelimiter(DELIMITER);
                String data = sc.next();               
                results.add(data);  // add the line to the list
            }

        } catch (Exception e) {
            System.out.println(e);
        }
        sc.close(); 
        // convert the list to an array and return it.
        return results.toArray(new String[results.size()]);
    }