Java Read/Write File

Question

I have a task to make simulator of examination. What I mean, student enter his first name, last name and birth after teacher input his marks in some subjects and then he decided does student passed subject or not. So, I have a question, how to write in file text with new line and read with rewriting this file(read line by line and rewrite). For example: I add a text like this in file Jimmy Kordon 05.10.1998 how to make new line for this, I mean after 1998 and then add another stroke. And it should looks like this:

Jimmy Kordon 05.10.1998
Alex Starr 12.09.2000

After this I call another method which rewrite into this

Jimmy Kordon 05.10.1998 200.0 yes
Alex Starr 12.09.2000 10.0 no

This is how I did it. I have a problem cause after rewriting I don't have a newline and if add new person this method just delete old info and then add new. What's the problem? Please help me.

It is a method for student to adding info(this method has student class).

public void write() throws IOException {
    Scanner in = new Scanner(System.in);
    System.out.println("Input name");
    String name = in.nextLine();
    setName(name);

    System.out.println("Input last name");
    String lastName = in.nextLine();
    setLastName(lastName);

    System.out.println("Input birthday");
    String birth = in.nextLine();
    setBirth(birth);

    String ex = getName() + " " + getLastName() + " " + getBirth();

    BufferedWriter writer = new BufferedWriter(new FileWriter("test.txt"));
    try {
        writer.write(getName() + " " + getLastName() + " " + getBirth());
        writer.newLine();
        //writer.close();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        writer.close();
    }
}

And this is a method which I call from teacher class to rewrite this info:

private void inputMarks() {
    Scanner in = new Scanner(System.in);

    System.out.println("Input Math mark");
    emM = new ExamMarks();
    emM.setMath(in.nextDouble());

    System.out.println("Input Physics mark");
    emP = new ExamMarks();
    emP.setPhysics(in.nextDouble());

    System.out.println("Input Ukrainian mark");
    emU = new ExamMarks();
    emU.setUkrainian(in.nextDouble());

    System.out.println("Input English mark");
    emE = new ExamMarks();
    emE.setEnglish(in.nextDouble());

}

private double Arithm(double Math, double Physics, double Ukrainian, double English) {
    double sum = Math + Physics + Ukrainian + English;
    double average = sum / 4.0;
    return average;
}

public void rewrite() {
    inputMarks();

    String a = read();

    System.out.println(Arithm(emM.getMath(), emP.getPhysics(), emU.getUkrainian(), emE.getEnglish()));

    Scanner in = new Scanner(System.in);
    System.out.println("Input yes/no");
    String YesNo = in.nextLine();

    try(BufferedWriter writer = new BufferedWriter(new FileWriter("test.txt"))) {
        writer.write(a + " " + Arithm(emM.getMath(), emP.getPhysics(), emU.getUkrainian(), emE.getEnglish())
                + " " + YesNo);
        writer.newLine();
        writer.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

Answer 1

Edit the code

try(BufferedWriter writer = new BufferedWriter(new FileWriter("test.txt")))

to

try(BufferedWriter writer = new BufferedWriter(new FileWriter("test.txt", true)))

This will enable the append mode instead of override the old data.