java FileReaderWriter

public static void main(String[] args) throws IOException {
  FileReader fr = new FileReader("C:/Users/宇超/Desktop/hello.txt");
  FileWriter fw = new FileWriter("C:/Users/宇超/Desktop/hello(1).txt");
  int b=0;
  int num = 0;
  while((b=fr.read())!=-1){
   fw.write(b);
   num++;
  }
  fr.close();
  fw.close();
  System.out.println("文件大小："+num+"字节大小");
 }