Subsequence words

Suppose this is my .txt file ABCDBCD and I want to use .substring to get this:
ABC BCD CDB DBC BCD

How can I achieve this? I also need to stop the program if a line is shorter than 3 characters.

static void lesFil(String fil, subsekvens allHashMapSubsequences) throws FileNotFoundException{
    Scanner scanner = new Scanner(new File("File1.txt"));
    String currentLine, subString;

    
    

        while(scanner.hasNextLine()){
            currentLine = scanner.nextLine();
            currentLine = currentLine.trim();

            for (int i = 0; i +  subSize <= currentLine.length(); i++){
    
                subString = currentLinje.substring(i, i + subSize);
                subSekStr.putIfAbsent(subString, new subsequence(subString));
            }
        }
    
   

    scanner.close();

>Solution :

With a minor changes of your code:

public static void main(String[] args) throws FileNotFoundException {
    Scanner scanner = new Scanner(new File("C:\\Users\\Public\\File1.txt"));
    String currentLine, subString;
    int subSize = 3;

    while (scanner.hasNextLine()) {
        currentLine = scanner.nextLine();
        currentLine = currentLine.trim();

        if (currentLine.length() < subSize) {
            break;
        }

        for (int i = 0; i + subSize <= currentLine.length(); i++) {

            subString = currentLine.substring(i, i + subSize);
            System.out.print(subString + " ");
        }

        System.out.print("\n");
    }

    scanner.close();
}