缓冲字符copy

public static void copyFile(String srcPath,String desPath) throws IOException{
  BufferedReader br = new BufferedReader(new FileReader(new File(srcPath)));
  BufferedWriter bw = new BufferedWriter(new FileWriter(desPath));
  
  String line = null;
  while((line = br.readLine())!=null){//readLine()每次读一行，读到文件末尾返回null。
   bw.write(line);//读取一行内容，不会把换行符读进来
   bw.newLine();//换行
  }
  
  bw.close();
  br.close();
}