执行 BufferedReader.close() 时 Hadoop FileSystem 关闭异常

From within the Reduce setup method,I am trying to close a BufferedReader object and getting a FileSystem closed exception. It does not happen all the time. This is the piece of code I used to create the BufferedReader.

    String fileName = <some HDFS file path>
    Configuration conf = new Configuration();
    FileSystem fs = FileSystem.get(conf);
    Path hdfsPath = new Path(filename);
    FSDataInputStream in = fs.open(hdfsPath);
    InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream);
    BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

我从 bufferedReader 读取内容，一旦所有读取完成，我就关闭它.

String line;
while ((line = reader.readLine()) != null) {
    // Do something
}

    if (bufferedReader != null) {
        bufferedReader.close();
    }