android-volley Getting started with android-volley

Remarks

Installation And Setup

Installation

Volley JCenter Gradle Import

//in your project's app level build.gradle compile 'com.android.volley:volley:1.0.0'  

Create a subclass of Application

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 ImageLoader getImageLoader() { getRequestQueue(); if (mImageLoader == null) { mImageLoader = new ImageLoader(this.mRequestQueue, new LruBitmapCache()); } return this.mImageLoader; } public <T> void addToRequestQueue(Request<T> req, String tag) { // set the default tag if tag is empty 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); } } }  

Create a StringRequest

 public class StringRequestActivity extends Activity { private String TAG = StringRequestActivity.class.getSimpleName(); private Button btnStringReq; private TextView msgResponse; // This tag will be used to cancel the request private String tag_string_req = "string_req"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_string); btnStringReq = (Button) findViewById(R.id.btnStringReq); msgResponse = (TextView) findViewById(R.id.msgResponse); btnStringReq.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { makeStringReq(); } }); } /** * Making json object request * */ private void makeStringReq() { StringRequest strReq = new StringRequest(Method.GET, "http://www.myurl.com", new Response.Listener<String>() { @Override public void onResponse(String response) { Log.d(TAG, response.toString()); msgResponse.setText(response.toString()); } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { VolleyLog.d(TAG, "Error: " + error.getMessage()); } }); // Adding request to request queue AppController.getInstance().addToRequestQueue(strReq, tag_string_req); } }  

Singleton RequestQueue Setup

Generally it's recommended that you use a single RequestQueue throughout your Application. So, you want to have one NetworkRequestManager singleton that contains your Volley RequestQueue. A simple implementation would be:

public class NetworkRequestManager { private static final String TAG = NetworkRequestManager.class.getName(); private static NetworkRequestManager mManager; private RequestQueue requestQueue; private NetworkRequestManager(@NonNull final Context context) { initQueue(context); } /** * @return A NetworkRequestManager with an initialized RequestQueue */ public static synchronized NetworkRequestManager getInstance(@NonNull final Context context) { if(mManager == null){ mManager = new NetworkRequestManager(context); } return mManager; } /** * Initialize your request queue. This uses the default Volley * setup. * * @param context */ private void initQueue(Context context) { if (requestQueue == null) { requestQueue = Volley.newRequestQueue(context.getApplicationContext()); } } /** * @Return our initialized RequestQueue */ public RequestQueue getRequestQueue() { return requestQueue; } /** * Cancels all requests for the given object tag * * @param tag */ @Override public void cancelAllForTag(Object tag) { getRequestQueue().cancelAll(tag); } /** * * A convenience method for adding requests to the queue that are associated with a tag for cancellation * * @param request * @param tag */ @Override public void addRequest(Request<?> request, Object tag) { request.setTag(tag); getRequestQueue().add(request); }  

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