How to cache data that comes from API in the app using the Room DB to make app work well in offline mode?
//This class explains how I insert data to room, but I don't know to update when user open the app for second time
private class InsertMain extends AsyncTask<Void, Void, Main> {
private Response main;
private WeakReference<SplashActivity> activityReference;
private Exception exceptionToBeThrown;
public InsertMain(SplashActivity context, Response main) {
activityReference = new WeakReference<>(context);
this.main = main;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
//Toast.makeText(SplashActivity.this, "جاري تحميل البيانات!", Toast.LENGTH_SHORT).show();
}
#Override
protected Main doInBackground(Void... mVoids) {
Main newData;
if (activityReference.get().responseDao != null) {
activityReference.get().responseDao.deleteContent(1);
}
try {
activityReference.get().roomDatabase.responseDao().insert(response);
} catch (Exception e) {
e.printStackTrace();
}
if (activityReference.get() != null) {
newData = new Gson().fromJson(activityReference.get().roomDatabase.responseDao().getContent(1), new TypeToken<Main>() {
}.getType());
return newData;
} else
return null;
}
#Override
protected void onPostExecute(Main mMain) {
super.onPostExecute(mMain);
handler = new Handler();
handler.postDelayed(task, 1000);
}
}
I have a problem with getting website with jsoup on Android.
public class Parser
{
Parser()
{
new Parser1().execute();
}
class Parser1 extends AsyncTask<Void, Void, Void>
{
String website1 = "http://google.com";
Document doc;
#Override
protected void onPreExecute()
{
super.onPreExecute();
}
This code is not execute doInBackground method.
#Override
protected Void doInBackground(Void... params)
{
try
{
doc = Jsoup.connect(website1).get();
}
catch (IOException e)
{
e.printStackTrace();
}
return null;
}
And the rest of code.
#Override
protected void onProgressUpdate(Void... values)
{
super.onProgressUpdate(values);
}
#Override
protected void onPostExecute(Void result)
{
Log.d ("OK",doc.toString());
super.onPostExecute(result);
}
#Override
protected void onCancelled()
{
super.onCancelled();
}
}
}
I tried to write code without class AsyncTask, but always on Json.connect the program was exception.
Thanks for all replies.
Try this:
#Override
protected Void doInBackground(Void... params) {
try {
doc = GetDocument(website1);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
Click the following link to get the full implementation of GetDocument.
References
How to use Jsoup with Volley?
you can use a httpURLconnections as an alternative and see if that works.
are you getting anything as the debug output for this code?
Log.d ("OK",doc.toString());
I've created an AsyncTask class to handle sending and receiving from my server. What I'm trying to do is fire an event or callback when the data is received so I can use said data to manipulate the UI.
AsyncTask class:
public class DataCollectClass extends AsyncTask<Object, Void, JSONObject> {
private JSONObject collected;
#Override
protected void onPreExecute() {
super.onPreExecute();
}
//#Override -Commented out because it doesn't like the override
protected void onPostExecute() {
try {
Log.d("Net", this.collected.getString("message"));
} catch (JSONException e) {
e.printStackTrace();
}
}
#Override
protected JSONObject doInBackground(Object... params) {
OkHttpClient client = new OkHttpClient();
// Get Parameters //
String requestURI = (String) params[0];
RequestBody formParameters = (RequestBody) params[1];
Request request = new Request.Builder().url(requestURI).post(formParameters).build();
client.newCall(request).enqueue(new Callback() {
#Override
public void onFailure(Call call, IOException e) {
// DO something on FAIL
}
#Override
public void onResponse(Call call, Response response) throws IOException {
String jsonResponse = response.body().string();
Log.d("Net", jsonResponse);
try {
DataCollectClass.this.collected = new JSONObject(jsonResponse);
Log.d("Net", DataCollectClass.this.collected.getString("message"));
} catch (JSONException e) {
e.printStackTrace();
}
}
});
return collected;
}
}
This is working, it prints an expected line of JSON into the log.
It's called from the Activity as:
new DataCollectClass().execute(requestURI, formVars);
I've looked all over, and I can't seem to find a definitive answer on how (and where) to add a callback. Preferably, the callback code itself should be with the DataCollectClass so all related code is reusable in the same place.
Is there a way to create a custom event firing (similar to Javascript libraries) that the program can listen for?
I've been pulling my hair out over this!
UPDATE:
Since AsyncTask is redundant, I've removed it and rewrote the code (in case someone else has this same issue):
public class DataCollectClass {
private JSONObject collected;
public interface OnDataCollectedCallback {
void onDataCollected(JSONObject data);
}
private OnDataCollectedCallback mCallback;
public DataCollectClass(OnDataCollectedCallback callback, String requestURI, RequestBody formParameters){
mCallback = callback;
this.collect(requestURI, formParameters);
}
public JSONObject collect(String requestURI, RequestBody formParameters) {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder().url(requestURI).post(formParameters).build();
client.newCall(request).enqueue(new Callback() {
#Override
public void onFailure(Call call, IOException e) {
//TODO Add what happens when shit fucks up...
}
#Override
public void onResponse(Call call, Response response) throws IOException {
String jsonResponse = response.body().string();
Log.d("Net", jsonResponse);
try {
DataCollectClass.this.collected = new JSONObject(jsonResponse);
if(mCallback != null)
mCallback.onDataCollected(DataCollectClass.this.collected);
} catch (JSONException e) {
e.printStackTrace();
}
}
});
return collected;
}
}
Called from Activity:
new DataCollectClass(new DataCollectClass.OnDataCollectedCallback() {
#Override
public void onDataCollected(JSONObject data) {
if(data != null) {
try {
// Do Something //
} catch (JSONException e) {
e.printStackTrace();
}
}
}
}, requestURI, formVars);
All working perfectly!
Thanks!
If you want to utilize a callback for an AsyncTask you can handle it via the following.
Do something like this (modifying your code to add what is below)
public class DataCollectClass extends AsyncTask<Object, Void, JSONObject> {
public interface OnDataCollectedCallback{
void onDataCollected(JSONObject data);
}
private OnDataCollectedCallback mCallback;
public DataCollectClass(OnDataCollectedCallback callback){
mCallback = callback;
}
// your code that is already there
...
#Override
public onPostExecute(JSONObject response){
if(mCallback != null)
mCallback.onDataCollected(response);
}
}
Then to make the magic happen
new DataCollectClass(new OnDataCollectedCallback() {
#Override
public void onDataCollected(JSONObject data) {
if(data != null)
// DO something with your data
}
}).execute(requestURI, formVars);
However, it is worth noting, most networking libraries, including OkHttp, handle background threads internally, and include callbacks to utilize with the requests.
This also implements a custom interface, so others may be able to see how you could use this for any AsyncTask.
There is a asynchronous get in OkHttp, so you don't need an AsyncTask, but as a learning exercise, you could define your callback as a parameter something like so.
new DataCollectClass(new Callback() {
#Override
public void onFailure(Call call, IOException e) {
// DO something on FAIL
}
#Override
public void onResponse(Call call, Response response) throws IOException {
JSONObject collected = null;
String jsonResponse = response.body().string();
Log.d("Callback - Net", jsonResponse);
try {
collected = new JSONObject(jsonResponse);
Log.d("Callback - Net", collected.getString("message"));
} catch (JSONException e) {
e.printStackTrace();
}
}
}).execute(requestURI, formVars);
The AsyncTask
public class DataCollectClass extends AsyncTask<Object, Void, Call> {
private Callback mCallback;
private OkHttpClient client;
public DataCollectClass(Callback callback) {
this.mCallback = callback;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
this.client = new OkHttpClient();
}
#Override
protected void onPostExecute(Call response) {
if (response != null && this.mCallback != null) {
response.enqueue(this.mCallback);
}
}
#Override
protected Call doInBackground(Object... params) {
// Get Parameters //
String requestURI = (String) params[0];
RequestBody formParameters = (RequestBody) params[1];
Request request = new Request.Builder().url(requestURI).post(formParameters).build();
return client.newCall(request); // returns to onPostExecute
}
}
Call Webservice using asynctask is an old fashioned. You can use Volley or retrofit.
But you can use this process to call Webservice . Here is steps:
Create an Interface and implements it in your Activity/Fragment
public interface IAsynchronousTask {
public void showProgressBar();
public void hideProgressBar();
public Object doInBackground();
public void processDataAfterDownload(Object data);
}
Create Class DownloadableAsyncTask . This class is:
import android.os.AsyncTask;
import android.util.Log;
public class DownloadableAsyncTask extends AsyncTask<Void, Void, Object> {
IAsynchronousTask asynchronousTask;
public DownloadableAsyncTask(IAsynchronousTask activity) {
this.asynchronousTask = activity;
}
#Override
protected void onPreExecute() {
if (asynchronousTask != null)
asynchronousTask.showProgressBar();
}
#Override
protected Object doInBackground(Void... params) {
try {
if (asynchronousTask != null) {
return asynchronousTask.doInBackground();
}
} catch (Exception ex) {
Log.d("BSS", ex.getMessage()==null?"":ex.getMessage());
}
return null;
}
#Override
protected void onPostExecute(Object result) {
if (asynchronousTask != null) {
asynchronousTask.hideProgressBar();
asynchronousTask.processDataAfterDownload(result);
}
}
}
Now in your Activity you will find this methods.
DownloadableAsyncTask downloadAsyncTask;
ProgressDialog dialog;
private void loadInformation() {
if (downloadAsyncTask != null)
downloadAsyncTask.cancel(true);
downloadAsyncTask = new DownloadableAsyncTask(this);
downloadAsyncTask.execute();
}
#Override
public void showProgressBar() {
dialog = new ProgressDialog(this, ProgressDialog.THEME_HOLO_LIGHT);
dialog.setMessage(" Plaese wait...");
dialog.setCancelable(false);
dialog.show();
}
#Override
public void hideProgressBar() {
dialog.dismiss();
}
#Override
public Object doInBackground() {
// Call your Web service and return value
}
#Override
public void processDataAfterDownload(Object data) {
if (data != null) {
// data is here
}else{
//"Internal Server Error!!!"
}
}
Now just call loadInformation() method then you will get your response on processDataAfterDownload().
I am following the documentation given by IBM (https://developer.ibm.com/mobilefirstplatform/documentation/getting-started-7-0/hello-world/creating-first-native-android-mobilefirst-application/)
After calling request.send(new MyInvokeListener()); there is no sucess or failure call back. Receiving an error message "Android Prototype stopped working."
Adapter is working fine when i right click on the adapter --> Run As --> Call Mobile First Adapter
Below is my android native code.
public class TaskFeed extends AsyncTask<Void, Void, String> {
ProgressDialog Dialog = new ProgressDialog(TaskActivity.this);
#Override
protected void onPreExecute() {
Dialog.setMessage("Establishing connection...");
Dialog.show();
}
#Override
protected String doInBackground(Void... params) {
try {
final WLClient client = WLClient.createInstance(TaskActivity.this);
client.connect(new MyConnectListener());
URI adapterPath = new URI("/adapters/TaskAdapter/getAllTasks");
WLResourceRequest request = new WLResourceRequest(adapterPath,WLResourceRequest.GET);
request.send(new MyInvokeListener());
} catch (Exception e) {
e.printStackTrace();
}
// Dialog.setMessage("Loading Tasks..");
return "test";
}
#Override
protected void onPostExecute(String r) {
Dialog.dismiss();
ArrayList<ListViewModel> result = AssignAndGetCurrentTaskResults();
tvListCount.setText(GetActionBarString());
adapter = new ArrayDataAdapter(taContext, R.layout.task_row_item, result);
listView.setAdapter(adapter);
adapter.notifyDataSetChanged();
}
}
My InvokeListner Class
public class MyInvokeListener implements WLResponseListener {
public void onSuccess(WLResponse response) {
try {
allTaskResults= ParseData(response.getResponseJSON().getJSONArray("array"));
}
catch (Exception ex)
{
ex.printStackTrace();
}
}
public void onFailure(WLFailResponse response) {
}
}
Taking out the code which creates and call to mobile first adapter from async task solved my problem.
There is a window leakage in android doing so.
Hello i have make one radio app in that streaming is done from web
my source code is
when user click on button following code will be executed
if (!NotifyService.iSserviceRunning) {
new PlayRadio().execute("");
}
// AYSNC class for start Service and create progressbar
class PlayRadio extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... urls) {
return "";
}
#Override
protected void onPostExecute(String result) {
try {
startService(new Intent(RadioActivity.this, NotifyService.class));
} catch (Exception e) {
e.printStackTrace();
}
}
#Override
protected void onPreExecute() {
super.onPreExecute();
try {
PD = ProgressDialog.show(RadioActivity.this, "Tuning...", "Please Wait...");
} catch (Exception e) {
e.printStackTrace();
}
}
}
//Now service class will be
public class NotifyService extends Service {
private static String RADIO_STATION_URL;
public static MediaPlayer player;
public static boolean iSserviceRunning = false;
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onCreate() {
super.onCreate();
RADIO_STATION_URL = getResources().getString(R.string.streamurl);
nm = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
initializeMediaPlayer();
startPlaying();
iSserviceRunning = true;
}
#Override
public void onDestroy() {
super.onDestroy();
nm.cancel(R.string.service_started);
stopPlaying();
initializeMediaPlayer();
iSserviceRunning = false;
}
private void startPlaying() {
player.setOnPreparedListener(new OnPreparedListener() {
public void onPrepared(MediaPlayer mp) {
player.start();
}
});
new PrepareTask().execute();
}
private void stopPlaying() {
if (player.isPlaying()) {
player.pause();
player.release();
}
}
private void initializeMediaPlayer() {
player = new MediaPlayer();
try {
player.setDataSource(RADIO_STATION_URL);
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private class PrepareTask extends AsyncTask<Integer, Integer, Integer> {
#Override
protected void onPreExecute() {
super.onPreExecute();
}
protected void onPostExecute(Integer result) {
if(RadioActivity.PD!=null){
if(RadioActivity.PD.isShowing()){
RadioActivity.PD.dismiss();
}
}
}
#Override
protected Integer doInBackground(Integer... arg0) {
try {
player.prepare();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}
}
is there any wrong i am doing becuase my client said that application is taking tooo much time for loading.. he told me that he has many such application which is loading fastly then my app
can any body suggest me is any wrong i have done in my code so it's taking much time?