Nrthugu

I have a text file and I want to update everytime only the last 3 labels

The changes will be made via ID (1,2 etc.)

p.g. (for ID=1 change: 10,18/10/18,7 to 12,21/10/18,2)

User.txt:

1,alex,pass,Admin,Alexandros,Karatzas,Male,18/10/1990,A'Likeiou,Antreas,Karatzas,6945952301,10,18/10/18,7

2,maria,pass1,User,Maria,Karatza,Female,18/10/1990,B'Likeiou,Antreas,Karatzas,6945952381,20,18/10/18,5

So after run i want to take this as output:

1,alex,pass,Admin,Alexandros,Karatzas,Male,18/10/1990,A'Likeiou,Antreas,Karatzas,6945952301,12,21/10/18,2

2,maria,pass1,User,Maria,Karatza,Female,18/10/1990,B'Likeiou,Antreas,Karatzas,6945952381,20,18/10/18,5

The code searches for ID, reads-writes data but how can i replace the last 3 labels everytime?

Source Code:

    @FXML 

         TextField ID3,abs,Dabs,Fabs

    @FXML

    public void UseAddAbs() throws IOException {                //Kanei Add tis Apousies sinfona me to ID

        String searchText = ID3.getText();

        Path p = Paths.get("src", "inware", "users.txt");

        Path tempFile = Files.createTempFile(p.getParent(), "usersTemp", ".txt");

        try (BufferedReader reader = Files.newBufferedReader(p);

                BufferedWriter writer = Files.newBufferedWriter(tempFile)) {

            String line;



            // copy everything until the id is found

            while ((line = reader.readLine()) != null) {

                writer.write(line);

                if (line.contains(searchText)) {

                    writer.write("," + Fabs.getText());

                    writer.write("," + Dabs.getText());

                    writer.write("," + abs.getText());

                    break;

                }

                writer.newLine();

            }



            // copy remaining lines

            if (line != null) {

                writer.newLine();

                while ((line = reader.readLine()) != null) {

                    writer.write(line);

                    writer.newLine();

                }

            }

        }



        // copy new file & delete temporary file

        Files.copy(tempFile, p, StandardCopyOption.REPLACE_EXISTING);

        Files.delete(tempFile);

    }

Split the lines and work on fields:

        while ((line = reader.readLine()) != null) {

            String fields = line.split("[,]");

            if (fields[0].equals(searchID)) {

                fields[12] = "12";

                fields[13] = "21/10/18";

                fields[14] = "2";

            }

            writer.println(String.join(",", fields));

        }

Update: my code:

public static void main(String args) {

    try {

        String searchText = "1";

        Path p = Paths.get(".", "users.txt");

        Path tempFile = Files.createTempFile(p.getParent(), "usersTemp", ".txt");

        try (BufferedReader reader = Files.newBufferedReader(p);

                BufferedWriter writer = Files.newBufferedWriter(tempFile)) {

            String line;



            // copy everything until the id is found

            while ((line = reader.readLine()) != null) {

                String fields = line.split("[,]");

                if (searchText.equals(fields[0])) {

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

                        System.out.println(i + ": " + fields[i]);

                    }

                    fields[12] = "12";

                    fields[13] = "21/10/18";

                    fields[14] = "2";

                }

                writer.write(String.join(",", fields));

                writer.newLine();

            }

        }



        // copy new file & delete temporary file

        Files.copy(tempFile, p, StandardCopyOption.REPLACE_EXISTING);

        Files.delete(tempFile);

    } catch (IOException ex) {

        Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);

    }

}

You can split line into array and update last 3 array elements.
Then all you have to do is build new line from that array and write this line instead of an old one.

Example:.

while ((line = reader.readLine()) != null) {

    if (line.contains(searchText)) {

        String updatedLine = updateLastNStrings(line, 3);

        writer.write(updatedLine);

        break;

    } else {

        writer.write(line);

    }

    writer.newLine();

}



private String updateLastNStrings(String line, int n) {

    String  parts = line.split(",");

    for (int i = parts.length - n; i < parts.length; i++) {

        // update String

        String newPart = parts[i] + "_UPDATED";

        parts[i] = newPart;

    }

    return String.join(",", parts);

}

Input:

1,alex,pass,Admin,Alexandros,Karatzas,Male,18/10/1990,A'Likeiou,Antreas,Karatzas,6945952301,10,18/10/18,7

2,maria,pass1,User,Maria,Karatza,Female,18/10/1990,B'Likeiou,Antreas,Karatzas,6945952381,20,18/10/18,5

Result

1,alex,pass,Admin,Alexandros,Karatzas,Male,18/10/1990,A'Likeiou,Antreas,Karatzas,6945952301,12_UPDATED,21/10/18_UPDATED,2_UPDATED

2,maria,pass1,User,Maria,Karatza,Female,18/10/1990,B'Likeiou,Antreas,Karatzas,6945952381,20,18/10/18,5

Note updated String with _UPDATED

Note

Besides all that, the code you found is flawed, since to find ID it is searching if line contains a charSequence. What if ID is a content of a line?

Example:

1,some_content,2,3

2,some_content,1

You try to find a line by id 2 and first line will be updated instead of a second one.