Java TestBufferRW

public static void main(String[] args) throws IOException {
  BufferedWriter bw = new BufferedWriter(
    new FileWriter("C:/Users/宇超/Desktop/rand.txt"));
  BufferedReader br = new BufferedReader(
    new FileReader("C:/Users/宇超/Desktop/rand.txt"));
  
  for (int i = 0; i < 50; i++) {
   bw.write(String.valueOf(Math.random()));
   bw.newLine();
  }
  bw.flush();
  bw.close();
  
  String str = null;
  while((str=br.readLine())!=null){
   System.out.println(str+"\n");
  }
  br.close();
 }