如何从php网站获取jsonobject数据

Question

我正在使用 instagram api 和

我要读取Json对象数据

我正在使用安卓工作室

数据是这样的：

    {"access_token": "1505236317.d0d63a5.7c51f076228e4b0fa40e2ed83666f709",
 "user": {"id": "1505236317", "username": "arash_s.t", "profile_picture": 
"https://scontent.cdninstagram.com/t51.2885-
19/s150x150/18878865_233940920435631_1005661172109672448_a.jpg", "full_name": 
"Arash", "bio": "\u13d8R\u13d8\u13a6H_\u13a6T. DONT CHOSE YOUR LIFE AS OTHERS
 .BUT CREAT IT WITHOUT LIMITATIONS\ud83c\udf0a", "website": ""}}

我正在使用这个类

public class JSONParser {

static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
    // Making HTTP request
    try {
        // defaultHttpClient
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpPost httpPost = new HttpPost(url);
        HttpResponse httpResponse = httpClient.execute(httpPost);
        HttpEntity httpEntity = httpResponse.getEntity();
        is = httpEntity.getContent();
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    try {
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                is, "iso-8859-1"), 8);
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
        is.close();
        json = sb.toString();
    } catch (Exception e) {
        Log.e("Buffer Error", "Error converting result " + e.toString());
    }
    // try parse the string to a JSON object
    try {
        jObj = new JSONObject(json);
    } catch (JSONException e) {
        Log.e("JSON Parser", "Error parsing data " + e.toString());
    }
    // return JSON String
    return jObj;
    }

}

我正在从 url 获取 json 对象---->

url = "https://api.instagram.com/oauth/access_token";
new JSONParse().execute();

---

我在下面代码中的这一行有问题

kelidestan = json.getJSONObject(json_name);

但是当我运行我的应用程序时 kelidetan 为空

public class JSONParse extends AsyncTask<String, String, JSONObject> {
        public ProgressDialog pDialog;
        @Override
        public void onPreExecute() {
            super.onPreExecute();
            /*pDialog = new ProgressDialog(Login.this);
            pDialog.setMessage("Getting Data ...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();*/
        }
        @Override
        public JSONObject doInBackground(String... args) {
            JSONParser jParser = new JSONParser();
            // Getting JSON from URL
            JSONObject json = jParser.getJSONFromUrl(url);
            return json;
        }
        @Override
        public void onPostExecute(JSONObject json) {
            //pDialog.dismiss();
            try {
                // kelidestan


kelidestan = json.getJSONObject(json_name);
                // build String



                final int len=kelidestan.length();
                final ProgressDialog p2Dialog = new ProgressDialog(Login.this);
                Login.this.runOnUiThread(new Runnable() {
                    public void run() {
                        p2Dialog.setMessage(len+"lolo");
                        p2Dialog.setIndeterminate(false);
                        p2Dialog.setCancelable(true);
                        p2Dialog.show();

                    }
                });






            } catch (final JSONException e) {
                Login.this.runOnUiThread(new Runnable() {
                    public void run() {
                        Toast.makeText(Login.this, (CharSequence) e.toString(), Toast.LENGTH_SHORT).show();

                    }
                });


            }
        }
    }

问题是：“如何从php网站读取json对象数据？”

用户名等："username": "arash_s.t"

Answer 1

** 使用 volley 库进行 GET 、 POST 和网络调用，非常简单高效**

首先创建 AppController.java

public class AppController extends Application {

    public static final String TAG = AppController.class.getSimpleName();

    private RequestQueue mRequestQueue;
    private ImageLoader mImageLoader;

    private static AppController mInstance;

    @Override
    public void onCreate() {
        super.onCreate();
        mInstance = this;
    }

    public static synchronized AppController getInstance() {
        return mInstance;
    }

    public RequestQueue getRequestQueue() {
        if (mRequestQueue == null) {
            mRequestQueue = Volley.newRequestQueue(getApplicationContext());
        }

        return mRequestQueue;
    }

    public <T> void addToRequestQueue(Request<T> req, String tag) {
        req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
        getRequestQueue().add(req);
    }

    public <T> void addToRequestQueue(Request<T> req) {
        req.setTag(TAG);
        getRequestQueue().add(req);
    }

    public void cancelPendingRequests(Object tag) {
        if (mRequestQueue != null) {
            mRequestQueue.cancelAll(tag);
        }
    }
    public ImageLoader getImageLoader() {
        getRequestQueue();
        if (mImageLoader == null) {
            mImageLoader = new ImageLoader(this.mRequestQueue,
                    new LruBitmapCache());
        }
        return this.mImageLoader;
    }

    public void setConnectivityListener(ConnectivityReceiver.ConnectivityReceiverListener listener) {
        ConnectivityReceiver.connectivityReceiverListener = listener;
    }
} 

提出获取请求

    private void makeJsonObjectRequest() {


    JsonObjectRequest jsonObjReq = new JsonObjectRequest(Method.GET,
            urlJsonObj, null, new Response.Listener<JSONObject>() {

                @Override
                public void onResponse(JSONObject response) {
                    Log.d(TAG, response.toString());

                    try {
                        // Parsing json object response
                        // response will be a json object
                        String name = response.getString("access_token");


                        jsonResponse = "";
                        jsonResponse += "Name: " + name ;

                        txtResponse.setText(jsonResponse);

                    } catch (JSONException e) {
                        e.printStackTrace();
                        Toast.makeText(getApplicationContext(),
                                "Error: " + e.getMessage(),
                                Toast.LENGTH_LONG).show();
                    }
                    hidepDialog();
                }
            }, new Response.ErrorListener() {

                @Override
                public void onErrorResponse(VolleyError error) {
                    VolleyLog.d(TAG, "Error: " + error.getMessage());
                    Toast.makeText(getApplicationContext(),
                            error.getMessage(), Toast.LENGTH_SHORT).show();
                    // hide the progress dialog
                }
            });

    // Adding request to request queue
    AppController.getInstance().addToRequestQueue(jsonObjReq);
}

包括凌空库

compile 'com.android.volley:volley:1.0.0'

不要忘记在清单文件的应用标签中添加android:name=".AppController"