Question

我试图从JSON获取URL数据时出现以下错误：

Value http of type java.lang.String cannot be converted to JSONObject

到目前为止，我使用了HttpClient，但是对于API23，它已被弃用，有人可以帮助我吗？

这就是我现在所拥有的：

@Override
protected String doInBackground(String... uri){

    String responseString = "...";

    URL url ;
    HttpURLConnection urlConnection = null;
    try {
        url = new URL(responseString);

        urlConnection = (HttpURLConnection) url
                .openConnection();

    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        assert urlConnection != null;
        urlConnection.disconnect();
    }

    return responseString;

}

这就是我所拥有的：

@Override
protected String doInBackGround(String...uri){
    String responseString = null;
    try {
        HttpClient client = new DefaultHttpClient();
        URI apiCall = new URI("...");
        HttpGet request = new HttpGet();
        request.setURI(apiCall);
        HttpResponse response = client.execute(request);
        responseString = EntityUtils.toString(response.getEntity());
    } catch (Exception e) {
        Log.e("TAG", "some sort of problem encountered", e);
    }
    return responseString;
}

Answer 1

您可以执行GET，

        URL u = new URL(url);
        c = (HttpURLConnection) u.openConnection();
        c.setRequestMethod("GET");
        c.setRequestProperty("Content-length", "0");
        c.setUseCaches(false);
        c.setAllowUserInteraction(false);
        c.setConnectTimeout(timeout);
        c.setReadTimeout(timeout);
        c.connect();
        int status = c.getResponseCode();

        switch (status) {
            case 200:
            case 201:
                BufferedReader br = new BufferedReader(new InputStreamReader(c.getInputStream()));
                StringBuilder sb = new StringBuilder();
                String line;
                while ((line = br.readLine()) != null) {
                    sb.append(line+"\n");
                }
                br.close();
                return sb.toString();
        }

要将json String转换为实际对象，可以使用Gson。或者您可以忘记这个HttpURLConnection apprach并使用Retrofit库来实现相同的结果。

Answer 2

您不会发布导致错误Value http of type java.lang.String cannot be converted to JSONObject的代码。但是，因为第一个代码段中的异步任务（使用HttpURLConnection）返回 responseString ，这是一个网址（例如以“http：//”开头），当然，它是不是有效的JSONObject。

使用HttpURLConnection在AsyncTask中获取JSON数据时出错

2 个答案: