Wsrtjtyk

I was trying to rewrite a line that contains student details in a txt file. There will be a list of students' detail in the file, for example:

• Name1,10


• Name2,20


• Name3,30

I tried to rewrite Name2,20 to Name2,13 using a BufferedReader to find the line with Name2. And a BufferedWriter to replace the line with new text, but it turns out the code will write my whole txt file to null.

Here's my code:

String lineText;

String newLine = "Name,age";

    try {

        BufferedReader br = new BufferedReader(new FileReader(path));

        BufferedWriter bw = new BufferedWriter(new FileWriter(path,false));

        while ((lineText = br.readLine()) != null){

             System.out.println(">" + lineText);

            String studentData = lineText.split(",");

            if(studentData[0].equals(Name2)){

                bw.write(newLine);

            }

            System.out.println(lineText);

        }

        br.close();

        bw.close();



        }

        catch (IOException e) {

            e.printStackTrace();

        }

Can anyone please tell me how to rewrite a specific line in txt file?

Easiest way is to read the entire file, and store it in a variable. Replacing the line in question while reading the current file.

Something like:

String lineText;

String newLine = "Name,age";

try {

    BufferedReader br = new BufferedReader(new FileReader(path));

    BufferedWriter bw = new BufferedWriter(new FileWriter(path,false));

    String currentFileContents = "";

    while ((lineText = br.readLine()) != null){

        System.out.println(">" + lineText);

        String studentData = lineText.split(",");

        if(studentData[0].equals("Name2")){

            currentFileContents += newLine;

        } else {

            currentFileContents += lineText;

        }

    }



    bw.write(currentFileContents);

    br.close();

    bw.close();



} catch (IOException e) {

    e.printStackTrace();

}