bufferedwriter 拒绝写入文本文件（Java）

Question

Whenever I call my method in my code, despite opening and closing my BufferedWriter correctly(I think) it still refuses to print to the text file that it is meant to print to Here is my code :

public Student(String nameInput, String gradeInput) throws IOException
    {
        BufferedWriter o = new BufferedWriter(new FileWriter("Students.txt"));
        name = nameInput;
        grade = gradeInput;
        o.write(gradeInput);
        o.newLine();
        o.write(nameInput);
        o.close(); 
    }

Answer 1

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;

public class Main {

    public static void Student(String nameInput, String gradeInput) throws IOException
    {
        BufferedWriter o = new BufferedWriter(new FileWriter("Students.txt"));
        String name = nameInput;
        String grade = gradeInput;
        o.write(gradeInput);
        o.newLine();
        o.write(nameInput);
        o.close(); 
    }
    public static void main(String[] args) throws IOException {
        // TODO Auto-generated method stub
        Student("ABC","A");
    }

}

Answer 2

在关闭BufferedWriter之前尝试使用o.flush() ，即o.close()