java - Java，读取空行

Question

如何读取空行此代码不添加空行，我尝试了此代码

BufferedReader r2 = new BufferedReader(new FileReader("Flags.txt"));
  StringBuffer sb = new StringBuffer();
  while ((r2.readLine()) != null) {
         sb.append(r2.readLine());
         sb.append("\r\n");
  }

      String str = sb.toString();
      System.out.println(str);

输出

    Dubai
    Qatar
    UAE
    United States

应该是这样的

    Dubai
    Qatar
    UAE

    United States

标签： java

Answer 1

你打readLine()了两次电话。执行以下操作：

String line = "";
while ((line = r2.readLine()) != null) {
     sb.append(line);
     //...
}