bufferedReader reader.readline 直接回null

Question

我正在使用 bufferedReader 並且奇怪的是，在我這樣做之后

reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));

EDIT3： BufferedReader 閱讀器本身知道完全加載且正確，但需要的 reader.readline 直接返回 null

誰能解釋一下我做錯了什么或為什么會發生這種情況？

編輯：我從 url 得到 json，這是這個

{"sports":[{"sport":{"id":"1","name":"yoga","rating":"1.6"}},{"sport":{"id":"2 ","name":"tennis","rating":"3.6"}},{"sport":{"id":"3","name":"zwemmen","rating":"4.7"} }],"view":{"name":"SportData","display":"page_1","path":"admin/content/data/view/SportData","root":"sports","child ":"sport","pages":null,"page":null,"count":3,"limit":null}}

所以當我調試這個時，我得到以下......

EDIT2：這是完整的代碼，

@Override
    protected Void doInBackground(String... type) {
        URL_STRING = "my json_url";
        ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = cm.getActiveNetworkInfo();
        if (networkInfo != null && networkInfo.isConnected()) {
            try
            {
                URL url;
                StringBuilder stringBuilder;
                    url = new URL(URL_STRING);
                    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.connect();
                    reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
                    stringBuilder = new StringBuilder();
                    while ((line =reader.readLine()) != null)
                    {
                        stringBuilder.append(line+"\n");
                    }
                    result =  stringBuilder.toString();
                }
                catch (Exception e)
                {
                }
        }
        return null;
    }

Answer 1

你的代碼沒有意義。 你永遠追加同一行。 你的循環應該是：

while ((line = reader.readLine()) != null)
{
    stringBuilder.append(line+"\n");
}

我還想知道您是否在同一個套接字上創建兩個BufferedReaders ，這也沒有意義。