如何正确关闭BufferedReader

Question

我有这个代码用于读取JSON文件：

Gson gson = new Gson();
BufferedReader bufferedReader = null;
try {
    bufferedReader = new BufferedReader(new FileReader(path));
    JsonObject data = gson.fromJson(bufferedReader, JsonObject.class);
    Log.d(TAG, "DATA: " + data.toString());
} catch (FileNotFoundException e) {
    e.printStackTrace();
} finally {
    if (bufferedReader != null) {
        try {
            bufferedReader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

代码似乎工作正常，但在logcat我收到这3行：

com.example.package W/System: A resource failed to call close. 
com.example.package W/System: A resource failed to call end. 
com.example.package W/System: A resource failed to call close. 

这是正常还是我做错了什么？提前谢谢了。

Answer 1

好的，@ deHaar，是对的：

try (BufferedReader bufferedReader = new BufferedReader(new FileReader(path))) {
    JsonObject data = gson.fromJson(bufferedReader, JsonObject.class);
    Log.d(TAG, "DATA: " + data.toString());
} catch (FileNotFoundException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
}

这样我就不会收到警告了。但我不明白为什么。如果有人可以在评论中写下来，我会很感激。谢谢。