java - 如何正确关闭BufferedReader

Question

我有这段读取 JSON 文件的代码:

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 中我收到以下 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. 

这是正常现象还是我做错了什么？非常感谢。

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。但我不明白为什么。如果有人可以在评论中写下它，我将不胜感激。谢谢。