How to load GridView images with AsyncTask?

How to load GridView images with AsyncTask? - android

I have, below the following fragment that populates a gridview with Bitmaps from URLs. The problem is that I know it's very 'heavy' work and done on the UI Thread so it's slowing the fragment down when loading the grid.
I've read that an AsyncTask is needed to carry out the 'heavy' work in the background but I can't find anything that seems to fit with what I want.
public class HomeFragment extends Fragment {
protected static final String TAG = null;
public HomeFragment(){}
GridView gridView;
private GridViewAdapter gridAdapter;
private SQLiteHandler db;
private SwipeRefreshLayout swipeLayout;
private ProgressDialog pDialog;
GPSTracker gps;
String uid;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
db = new SQLiteHandler(getActivity());
gridAdapter = new GridViewAdapter(getActivity(), R.layout.grid_item_layout, getData());
pDialog = new ProgressDialog(getActivity());
pDialog.setCancelable(true);
uid="1";
String email = db.getFromTable(getActivity(), "email", SQLiteHandler.TABLE_LOGIN, "WHERE _id="+uid);
String from_age = db.getFromTable(getActivity(), "from_age", SQLiteHandler.TABLE_SETTINGS, "WHERE uid="+uid);
String to_age = db.getFromTable(getActivity(), "to_age", SQLiteHandler.TABLE_SETTINGS, "WHERE uid="+uid);
String distance = db.getFromTable(getActivity(), "distance", SQLiteHandler.TABLE_SETTINGS, "WHERE uid="+uid);
String unit = db.getFromTable(getActivity(), "unit", SQLiteHandler.TABLE_SETTINGS, "WHERE uid="+uid);
String men = db.getFromTable(getActivity(), "men", SQLiteHandler.TABLE_SETTINGS, "WHERE uid="+uid);
String women = db.getFromTable(getActivity(), "women", SQLiteHandler.TABLE_SETTINGS, "WHERE uid="+uid);
fetchUsers(email, from_age, to_age, distance, unit, men, women);
final View rootView = inflater.inflate(R.layout.fragment_home, container, false);
//getActivity().getActionBar().setTitle(R.string.home);
gridView = (GridView) rootView.findViewById(R.id.gridView);
gridView.setAdapter(gridAdapter);
gridView.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
ImageItem item = (ImageItem) parent.getItemAtPosition(position);
ImageView imageView = (ImageView) v.findViewById(R.id.image);
//Create intent
Intent intent = new Intent(getActivity(), DetailsActivity.class);
int[] screenLocation = new int[2];
imageView.getLocationOnScreen(screenLocation);
intent.putExtra("left", screenLocation[0]).
putExtra("top", screenLocation[1]).
putExtra("width", imageView.getWidth()).
putExtra("height", imageView.getHeight()).
putExtra("uid", item.getUid());
startActivity(intent);
}
});
swipeLayout = (SwipeRefreshLayout) rootView.findViewById(R.id.swipe_container);
swipeLayout.setOnRefreshListener(new OnRefreshListener() {
#Override
public void onRefresh() {
//my update process
Fragment currentFragment = getFragmentManager().findFragmentByTag("0");
FragmentTransaction fragTransaction = getFragmentManager().beginTransaction();
fragTransaction.detach(currentFragment);
fragTransaction.attach(currentFragment);
fragTransaction.commit();
}
});
return rootView;
}
// Prepare some dummy data for gridview
private ArrayList<ImageItem> getData() {
final ArrayList<ImageItem> imageItems = new ArrayList<>();
Cursor cursor = db.getAllRows("*", SQLiteHandler.TABLE_USERS, "");
//Query local DB to initialize settings screen
for(cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()){
String uid = cursor.getString(cursor.getColumnIndex(SQLiteHandler.KEY_UID));
String name = cursor.getString(cursor.getColumnIndex(SQLiteHandler.KEY_NAME));
String dob = cursor.getString(cursor.getColumnIndex(SQLiteHandler.KEY_DOB));
//String gender = cursor.getString(cursor.getColumnIndex(SQLiteHandler.KEY_GENDER));
String photourl = cursor.getString(cursor.getColumnIndex(SQLiteHandler.KEY_PHOTOURL));
//String distance = cursor.getString(cursor.getColumnIndex(SQLiteHandler.KEY_DISTANCE));
String[] birthdayArr = dob.split("-");
int age = getAge(Integer.parseInt(birthdayArr[0]), Integer.parseInt(birthdayArr[1]), Integer.parseInt(birthdayArr[2]));
Bitmap bitmap = getBitmapFromURL(photourl);
imageItems.add(new ImageItem(bitmap, name+" - " + age, uid));
}
return imageItems;
}
public static Bitmap getBitmapFromURL(String src) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
try {
URL url = new URL(src);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
return myBitmap;
} catch (IOException e) {
// Log exception
return null;
}
}
public int getAge(int year, int month, int day) {
//int nowMonth = now.getMonth()+1;
int nowMonth = Calendar.getInstance().get(Calendar.DAY_OF_MONTH);
//int nowYear = now.getYear()+1900;
int nowYear = Calendar.getInstance().get(Calendar.YEAR);
int result = nowYear - year;
if (month > nowMonth) {
result--;
}
else if (month == nowMonth) {
int nowDay = Calendar.getInstance().get(Calendar.DATE);
if (day > nowDay) {
result--;
}
}
return result;
}
private void showDialog() {
if (!pDialog.isShowing())
pDialog.show();
}
private void hideDialog() {
Log.i("hideDialog", "called");
if (pDialog.isShowing())
pDialog.dismiss();
}
public void fetchUsers(final String email, final String agefrom, final String ageto, final String distance, final String distanceUnit, final String interested_men, final String interested_wmen){
// Tag used to cancel the request
gps = new GPSTracker(getActivity());
String tag_string_req = "req_login";
pDialog.setMessage("Finding users ...");
showDialog();
StringRequest strReq = new StringRequest(Method.POST,
AppConfig.URL_LOGIN, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.d(TAG, "Fetch Response: " + response.toString());
hideDialog();
try {
JSONObject jObj = new JSONObject(response);
int success = jObj.getInt("success");
JSONArray users = jObj.getJSONArray("users");
// Check for error node in json
if (success == 1) {
//Log.i("success", users+"");
if (users.length() == 0) {
Toast.makeText(getActivity(), "No users found! \nPlease try again soon.", Toast.LENGTH_LONG).show();
db.emptyTable(SQLiteHandler.TABLE_USERS);
}else{
db.emptyTable(SQLiteHandler.TABLE_USERS);
for (int i = 0; i < users.length(); i++) {
JSONObject user = users.getJSONObject(i);
String uid = user.getString("uid");
String name = user.getString("name");
String dob = user.getString("dob");
String gender = user.getString("gender");
String photourl = user.getString("photoUrl");
String distance = user.getString("distance");
String[][] userValues = {
{ SQLiteHandler.KEY_UID, uid},
{ SQLiteHandler.KEY_NAME, name},
{ SQLiteHandler.KEY_DOB, dob},
{ SQLiteHandler.KEY_GENDER, gender},
{ SQLiteHandler.KEY_PHOTOURL, photourl},
{ SQLiteHandler.KEY_DISTANCE, distance}
};
db.insert(SQLiteHandler.TABLE_USERS, userValues);
}
}
} else {
// Error in login. Get the error message
String errorMsg = jObj.getString("error_msg");
Toast.makeText(getActivity(),errorMsg, Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
// JSON error
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Login Error: " + error.getMessage());
Toast.makeText(getActivity(),
error.getMessage(), Toast.LENGTH_LONG).show();
hideDialog();
}
}) {
#Override
protected Map<String, String> getParams() {
// Posting parameters to login url
//$lat, $lng, $email, $agefrom, $ageto, $distance, $distanceUnit, $interested_men, $interested_wmen
Map<String, String> params = new HashMap<String, String>();
params.put("tag", "login");
params.put("lat", gps.getLatitude()+"");
params.put("lng", gps.getLongitude()+"");
params.put("email", email);
params.put("agefrom", agefrom);
params.put("ageto", ageto);
params.put("distance", distance);
params.put("distanceUnit", distanceUnit);
params.put("interested_men", interested_men+"");
params.put("interested_wmen", interested_wmen+"");
params.put("fetch", "y");
Log.i(TAG, params+"");
return params;
}
};
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
}
}

How to load GridView images with AsyncTask?
Downloading images as Bitmap in HomeFragment. Use NetworkImageView from Volley in layout of GridView item for loading images in GridView.
Instead of storing Bitmap, store image url in ImageItem.
See following tutorial for more help:
Using NetworkImageView

AsynTask class
public class GridDataAsyncTask extends AsyncTask<GridDataAsyncTask.GridCallback, Void, GridAdapter> {
public interface GridCallback {
void onAdapterReady(GridAdapter adapter);
}
private GridCallback mCallBack;
#Override
protected GridAdapter doInBackground(GridCallback... callbacks) {
mCallBack = callbacks[0];
// TODO get data and create grid adapter
return adapter;
}
#Override
protected void onPostExecute(GridAdapter gridAdapter) {
super.onPostExecute(gridAdapter);
mCallBack.onAdapterReady(gridAdapter);
}
}
Activity
public class GridActivity extends AppCompatActivity implements GridDataAsyncTask.GridCallback {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
new GridDataAsyncTask().execute(this);
}
#Override
public void onAdapterReady(GridAdapter adapter) {
// TODO set adapte to GridView
}
}

Best you can do is use http://developer.android.com/reference/java/util/concurrent/ThreadPoolExecutor.html and make a lru cache and place the images in lru cache.
Example is given in android tutorials
http://developer.android.com/training/displaying-bitmaps/cache-bitmap.html

As suggested by fractalwrench and Budius, Picasso was a very good and VERY easy solution to this. All I had to do was to pass the photo url instead of the entire BitMap through to my GridView adapter and use Picasso.with(context).load(item.getImage()).into(holder.image); to create the BitMap for the image view. This was so easy to implement and gives me exactly what I need. Thaks

Related

How to Send All Data From SQLite to Server in Android

Here I am sending data from local data base to mysql database server but aly first row data is uploading
Can anyone help me
here i am fetching data from sqlite using model class and display in recyclerview
now i want to send all recyclerview data in ARRAY or any other way to server database
Here 6 images are fetch from sqlite also send to server without setImage in UI directly want to send to Server
Thanks in advance....!!!
Activity Code
public class FetchLocalInsuranceListActivity extends AppCompatActivity {
protected ViewDialog viewDialog;
private RecyclerView recyclerview;
RequestQueue requestQueue;
private MyCustomAdapter myCustomAdapter;
Context context;
DatabaseHelper database;
List<DataModel> datamodel;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fetch_local_insurance_list);
context = this;
datamodel = new ArrayList<DataModel>();
viewDialog = new ViewDialog(this);
viewDialog.setCancelable(false);
database = new DatabaseHelper(context);
datamodel = database.getAllSyncData();
recyclerview = (RecyclerView) findViewById(R.id.recycler_view__local_my_insurance);
LinearLayoutManager layoutManager = new LinearLayoutManager(FetchLocalInsuranceListActivity.this);
layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
recyclerview.setLayoutManager(layoutManager);
recyclerview.setHasFixedSize(true);
myCustomAdapter = new MyCustomAdapter(datamodel);
recyclerview.setAdapter(myCustomAdapter);
}
public class MyCustomAdapter extends RecyclerView.Adapter<MyCustomAdapter.MyViewHolder> {
private List<DataModel> moviesList;
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView farmer_name, tv_Tagging_Date, tv_insurance_id;
protected ImageButton editButton;
public MyViewHolder(View view) {
super(view);
farmer_name = view.findViewById(R.id.text_insured_name);
tv_Tagging_Date = view.findViewById(R.id.tv_Tagging_Date);
tv_insurance_id = view.findViewById(R.id.tv_insurance_id);
editButton = itemView.findViewById(R.id.edit_button);
}
}
public MyCustomAdapter(List<DataModel> moviesList) {
this.moviesList = moviesList;
}
#Override
public MyCustomAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.layout_local_insurance_list, parent, false);
return new MyCustomAdapter.MyViewHolder(itemView);
}
public void clear() {
int size = this.moviesList.size();
if (size > 0) {
for (int i = 0; i < size; i++) {
this.moviesList.remove(0);
}
this.notifyItemRangeRemoved(0, size);
}
}
#SuppressLint("SetTextI18n")
#Override
public void onBindViewHolder(MyCustomAdapter.MyViewHolder holder, final int position) {
final DataModel datum = moviesList.get(position);
Log.e("image", datum.getAnimal_Tail_Photo() + "");
holder.farmer_name.setText("Farmer Name : " + datum.getFarmer_name() + "");
holder.tv_Tagging_Date.setText("Tagging Date : " + datum.getTagging_date() + "");
holder.tv_insurance_id.setText("#SNV_INSURANCE_" + datum.getId() + " ");
holder.editButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
editDataParticularRow(datum);
}
});
}
#Override
public int getItemCount() {
return moviesList.size();
}
}
private void editDataParticularRow(DataModel dataModel) {
Intent intent = new Intent(FetchLocalInsuranceListActivity.this, EditBankAndFarmerActivity.class);
intent.putExtra("BANK_ID", dataModel.getId() + "");
Log.e("id", dataModel.getId() + "");
startActivity(intent);
}
protected final void hideProgressDialog() {
viewDialog.dismiss();
}
protected void showProgressDialog() {
viewDialog.show();
}
protected void showProgressDialog(String message) {
showProgressDialog();
}
public void doNormalPostOperation(final int i) {
requestQueue = Volley.newRequestQueue(FetchLocalInsuranceListActivity.this);
final ProgressDialog progressDialog = new ProgressDialog(FetchLocalInsuranceListActivity.this);
progressDialog.setMessage("Saving Name...");
progressDialog.show();
final StringRequest stringRequest = new StringRequest(Request.Method.POST, "http://thelastoffers.com/snv/webservices/test.php",
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
progressDialog.dismiss();
database.deleteData(Integer.parseInt(datamodel.get(i).getId() + ""));
database.deleteAnimalData(Integer.parseInt(datamodel.get(i).getFarmer_id() + ""));
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
progressDialog.dismiss();
Toast.makeText(FetchLocalInsuranceListActivity.this, "Something went Wrong.. Please Try again..", Toast.LENGTH_SHORT).show();
}
}) {
#Override
protected Map<String, String> getParams() {
HashMap<String, String> params = new HashMap<String, String>();
// params.put("id", datamodel.get(i).getINSURANCE_ID() + "");
// REMAINING PARAMS WITH SAME datamodel.get(i) item
params.put("type", "insertOfflineData");
params.put("id", datamodel.get(i).getINSURANCE_ID() + "");
params.put("head_image_blob", String.valueOf(datamodel.get(i).getAnimal_Tag_Photo()));
params.put("farmer_bank_hypo", datamodel.get(i).getFarmer_bank_hypo() + "");
params.put("farmer_name", datamodel.get(i).getFarmer_name() + "");
params.put("farmer_village", datamodel.get(i).getVillage() + "");
params.put("farmer_taluka", datamodel.get(i).getTaluka() + "");
params.put("farmer_district", datamodel.get(i).getDistrict() + "");
params.put("tagging_date", datamodel.get(i).getTagging_date() + "");
Log.e("Data", params + "");
return params;
}
};
requestQueue.add(stringRequest);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater menuInflater = getMenuInflater();
menuInflater.inflate(R.menu.sync_menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_sync:
for (int i = 0; i < datamodel.size(); i++) {
doNormalPostOperation(i);
}
return true;
}
return super.onOptionsItemSelected(item);
}
}
Database Code
public List<DataModel> getAllSyncData() {
List<DataModel> data = new ArrayList<>();
SQLiteDatabase db = this.getWritableDatabase();
String query = "SELECT * FROM FARMER_SYNC_TABLE LEFT JOIN ANIMAL_SYNC_TABLE ON farmer_id = new_insurane_id ORDER BY new_insurane_id DESC";
Cursor cursor = db.rawQuery(query, null);
Log.e("value", query + ";" + " ");
StringBuilder stringBuffer = new StringBuilder();
if (cursor.moveToFirst()) {
do {
DataModel dataModel_1 = new DataModel();
int NEW_INSURANCE_ID_1 = cursor.getInt(cursor.getColumnIndexOrThrow("new_insurane_id"));
String INSURANCE_ID_1 = cursor.getString(cursor.getColumnIndexOrThrow("insurance_id"));
String INSURED_NAME_1 = cursor.getString(cursor.getColumnIndexOrThrow("insured_name"));
String BANKHYPO_NAME_1 = cursor.getString(cursor.getColumnIndexOrThrow("bankhypo_name"));
String FARMER_NAME_1 = cursor.getString(cursor.getColumnIndexOrThrow("farmer_name"));
String VILLAGE_1 = cursor.getString(cursor.getColumnIndexOrThrow("village"));
String TALUKA_1 = cursor.getString(cursor.getColumnIndexOrThrow("taluka"));
String DISTRICT_1 = cursor.getString(cursor.getColumnIndexOrThrow("district"));
String TAGGING_DATE_1 = cursor.getString(cursor.getColumnIndexOrThrow("tagging_date"));
int NEW_ANIMAL_ID = cursor.getInt(cursor.getColumnIndexOrThrow("new_animal_id"));
int FARMER_ID_1 = cursor.getInt(cursor.getColumnIndexOrThrow("farmer_id"));
String TAG_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("tag_no"));
String ANIMAL_EAR_POSITION_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("animal_ear_position"));
String ANIMAL_SPECIES_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("animal_species"));
String ANIMAL_BREED_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("animal_breed"));
String ANIMAL_BODY_COLOR_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("animal_body_color"));
String ANIMAL_SHAPE_RIGHT_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("animal_shape_right"));
String ANIMAL_SHAPE_LEFT_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("animal_shape_left"));
String ANIMAL_SWITCH_OF_TAIL_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("animal_sitch_of_tail"));
String AGE_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("age_years"));
String ANIMAL_OTHER_MARKS_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("animal_other_marks"));
String PRAG_STATUS_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("prag_status"));
String NUMBER_OF_LACTATION_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("number_of_lactation"));
String CURRENT_MILK_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("current_milk"));
String SUM_INSURED_COLUMN_1 = cursor.getString(cursor.getColumnIndexOrThrow("sum_insured"));
dataModel_1.setId(NEW_INSURANCE_ID_1);
dataModel_1.setINSURANCE_ID(INSURANCE_ID_1);
dataModel_1.setFarmer_insure_name(INSURED_NAME_1);
dataModel_1.setFarmer_bank_hypo(BANKHYPO_NAME_1);
dataModel_1.setFarmer_name(FARMER_NAME_1);
dataModel_1.setVillage(VILLAGE_1);
dataModel_1.setTaluka(TALUKA_1);
dataModel_1.setDistrict(DISTRICT_1);
dataModel_1.setTagging_date(TAGGING_DATE_1);
dataModel_1.setAnimal_id(NEW_ANIMAL_ID);
dataModel_1.setFarmer_id(FARMER_ID_1);
dataModel_1.setTag_no(TAG_COLUMN_1);
dataModel_1.setEar_position(ANIMAL_EAR_POSITION_COLUMN_1);
dataModel_1.setAnimal_species(ANIMAL_SPECIES_COLUMN_1);
dataModel_1.setAnimal_breed(ANIMAL_BREED_COLUMN_1);
dataModel_1.setBody_color(ANIMAL_BODY_COLOR_COLUMN_1);
dataModel_1.setShape_right(ANIMAL_SHAPE_RIGHT_COLUMN_1);
dataModel_1.setShape_left(ANIMAL_SHAPE_LEFT_COLUMN_1);
dataModel_1.setTail_switch(ANIMAL_SWITCH_OF_TAIL_COLUMN_1);
dataModel_1.setAge(AGE_COLUMN_1);
dataModel_1.setOther_marks(ANIMAL_OTHER_MARKS_COLUMN_1);
dataModel_1.setPrag_status(PRAG_STATUS_COLUMN_1);
dataModel_1.setLactations(NUMBER_OF_LACTATION_COLUMN_1);
dataModel_1.setMilk_qty(CURRENT_MILK_COLUMN_1);
dataModel_1.setSum_insured(SUM_INSURED_COLUMN_1);
dataModel_1.setAnimal_Tag_Photo(Utils.getBitmapFromByte(cursor.getBlob(cursor.getColumnIndex("tag_image"))));
dataModel_1.setAnimal_Head_Photo(Utils.getBitmapFromByte(cursor.getBlob(cursor.getColumnIndex("head_image"))));
dataModel_1.setAnimal_Left_Photo(Utils.getBitmapFromByte(cursor.getBlob(cursor.getColumnIndex("left_side_image"))));
dataModel_1.setAnimal_Right_Photo(Utils.getBitmapFromByte(cursor.getBlob(cursor.getColumnIndex("right_side_image"))));
dataModel_1.setAnimal_Tail_Photo(Utils.getBitmapFromByte(cursor.getBlob(cursor.getColumnIndex("tail_image"))));
dataModel_1.setAnimal_Farmer_Photo(Utils.getBitmapFromByte(cursor.getBlob(cursor.getColumnIndex("farmer_image"))));
stringBuffer.append(dataModel_1);
data.add(dataModel_1);
} while (cursor.moveToNext());
}
db.close();
return data;
}

This is a simple problem. You are only using
use for loop to iterate through all items like,
for(int i=0; i<datamodel.size(); i++){
doNormalPostOperation(i)
}
and in doNormalPostOperation method
public void doNormalPostOperation(int i) {
// PREVIOUS CODE
#Override
protected Map<String, String> getParams() {
params.put("id", datamodel.get(i).getINSURANCE_ID() + "");
// REMAINING PARAMS WITH SAME datamodel.get(i) item
}
}
which is causing that issue and only sending first item. You will need to iterate through all items to generate parameters and send to server, or else you can combine them to one json array and modify the code server side.

First you collect the Data from sqltables
/* Collecting Information */
public Cursor getAllData() {
String selectQuery = "Select * from "+TABLE_MEMBER;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
return cursor;
}
public JSONObject createJsonObject(){
Cursor cursor = getAllData();
JSONObject jobj ;
JSONArray arr = new JSONArray();
cursor.moveToFIrst();
while(cursor.moveToNext()) {
jobj = new JSONObject();
jboj.put("Id", cursor.getInt("Id"));
jboj.put("Name", cursor.getString("Name"));
arr.put(jobj);
}
jobj = new JSONObject();
jobj.put("data", arr);
}
public void postJsonToServer(){
JSONObject js = createJsonObject();
String url = "YOUR -- Post Url";
JsonObjectRequest jsonObjReq = new JsonObjectRequest(
Request.Method.POST,url, js,
new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
Log.d(TAG, response.toString());
msgResponse.setText(response.toString());
hideProgressDialog();
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
hideProgressDialog();
}
}) {
/**
* Passing some request headers
* */
#Override
public Map<String, String> getHeaders() throws AuthFailureError {
HashMap<String, String> headers = new HashMap<String, String>();
headers.put("Content-Type", "application/json; charset=utf-8");
return headers;
}
}

You can go through this:
Get all the data which you want to send, via select query and store this data in a array list.
Using GSON library you can convert that arraylist into json data
Now you have to create an API which receive that json data and parse it and insert every record to database.
On the app end you have to hit that API and pass json data to it.

RecyclerView not showing JSON sent from localhost just blank screen

Hi guys I dont have much experience with AsyncTask and this is my first time using RecyclerView besides a couple of tutorials I done to learn about it.
If I use dummy data in EventActivity everything works fine and a list shown on the screen. But when I create an ArrayList of EventItems and pass that to the adapter it's just a blank screen. The JSON from localhost is being parsed and sent to the EventItem class. I have tried several things to get it to work but as my experience with AsyncTask and RecyclerView are limited I end up just crashing the app and getting a null pointer exception.
I think that the RecyclerView is being created before the JSON has been retrieved from localhost and this is what's causing the blank screen or null pointer exception but I'm not 100% sure and dont know how to fix the issue if I am correct.
Any help is appreciated.
EventActivity
public class EventActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_event);
fetchEvents();//call EventBackgroundWorker
//ArrayList<EventItem> eventList = new EventItem().getRecyclerList();//causes java null pointer exception
ArrayList<EventItem> eventList = new ArrayList<>();
//Dummie data
// eventList.add(new EventItem (1, "Title1", "Date", "endDate", "Location1", 5, 1111));
// eventList.add(new EventItem (R.drawable.ic_favourite, "Title2", "11/07/2018", "11/07/2018", "Wales", 10, 5));
// eventList.add(new EventItem (R.drawable.ramspeed_custom, "Title3", "11/01/2018", "11/09/2018", "Paris, France", 0, 90));
// eventList.add(new EventItem (R.drawable.ramspeed_custom, "Title4", "12/01/2018", "11/09/2018", "New York", 20, 500));
// eventList.add(new EventItem (R.drawable.ic_favourite, "Title5", "Mon 11/05/2015", "11/09/2018", "London, England", 5, 500));
// eventList.add(new EventItem (R.drawable.biker, "Title6", "Mon 11/05/2018", "20/07/2018", "Swords Dublin", 0, 500));
mRecyclerView = (RecyclerView) findViewById(R.id.event_recycler_view);
mRecyclerView.setHasFixedSize(true);//increase performance of app if recyclerView does not increase in size
mLayoutManager = new LinearLayoutManager(this);
// mAdapter = new EventAdapter(eventList);
mAdapter = new EventAdapter(eventList);//context added for testing //////////////////////////////
// mAdapter = new EventAdapter(new ArrayList<EventItem>(0));
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setAdapter(mAdapter);
// buildRecyclerView();
}
//run background thread
private void fetchEvents(){
// String username = "user";
// String userPassword = "password";
String startConnectionCondition = "event";
//this passes the context
EventBackgroundWorker backgroundWorker = new EventBackgroundWorker(this);
backgroundWorker.execute(startConnectionCondition, null);
}
/* private void buildRecyclerView(){
ArrayList<EventItem> eventList = new EventItem().getRecyclerList();
mRecyclerView = (RecyclerView) findViewById(R.id.event_recycler_view);
mRecyclerView.setHasFixedSize(true);//increase performance of app if recyclerView does not increase in size
mLayoutManager = new LinearLayoutManager(this);
// mAdapter = new EventAdapter(eventList);
mAdapter = new EventAdapter(eventList);//context added for testing
// mAdapter = new EventAdapter(new ArrayList<EventItem>(0));
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setAdapter(mAdapter);
}
*/
/* public void showEventList(boolean b){
ArrayList<EventItem> eventList = new ArrayList<>();
for(int i =0; i< eventList.size(); i++){
eventList.get(i);
Log.d("tag","eventList from main " + eventList);
}
mAdapter = new EventAdapter(eventList);
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setAdapter(mAdapter);
}*/
}//MainActivity
EventAdapter
public class EventAdapter extends RecyclerView.Adapter<EventAdapter.EventViewHolder> {
private ArrayList<EventItem> mEventList;
Context context;
//constructor for EventAdapter
public EventAdapter(ArrayList<EventItem> eventList){
// context =c;
mEventList = eventList;
Log.d("tag","EventAdapter eventlist variable called from constructor " + eventList);
}
public static class EventViewHolder extends RecyclerView.ViewHolder{
public ImageView mPromoImage;
public TextView mTitle;
public TextView mStartDate;
public TextView mEndDate;
public TextView mLocation;
public TextView mFee;
public ImageView mFavourite;
//constructor for EventViewHolder class
public EventViewHolder(View itemView) {
super(itemView);
// mPromoImage = (ImageView) itemView.findViewById(R.id.event_promotional_image);
mTitle = (TextView) itemView.findViewById(R.id.event_title_textView);
mStartDate = (TextView) itemView.findViewById(R.id.event_start_textView);
mEndDate = (TextView) itemView.findViewById(R.id.event_end_textView);
mLocation = (TextView) itemView.findViewById(R.id.event_location_textView);
mFee = (TextView) itemView.findViewById(R.id.event_fee_textView);
// mFavourite = (ImageView) itemView.findViewById(R.id.event_favourite_image);
Log.d("tag", "EventViewHolder being called");
}
}//EventViewHolder class
#Override
public EventViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_event, parent, false);
//create view holder
EventViewHolder viewHolder = new EventViewHolder(v);
return viewHolder;
}
//pass values to inflated XML Views in item_event.xml
#Override
public void onBindViewHolder(EventViewHolder holder, int position) {
EventItem currentEvent = mEventList.get(position);
// holder.mPromoImage.setImageResource(currentEvent.getEventPromoImage());
holder.mTitle.setText(currentEvent.getEventTitle());
holder.mStartDate.setText(currentEvent.getEventStartDate());
holder.mEndDate.setText(currentEvent.getEventEndDate());
holder.mLocation.setText(currentEvent.getEventLocation());
holder.mFee.setText(String.valueOf(currentEvent.getEventFee()));//int value passed
// holder.mFavourite.setImageResource(currentEvent.getEventFavourite());
//Log.d("tag", "position" + position );
Log.d("tag","eventAdapter " + currentEvent.getEventTitle());
}
//how many items there will be
#Override
public int getItemCount() {
return mEventList.size();
}
}
EventItem
public class EventItem {
private int mEventPromoImage;
private int mId;
private String mEventTitle;
private String mEventStartDate;
private String mEventEndDate;
private String mEventLocation;
private int mEventFee;
private int mEventViews;
// public EventItem(){}
public EventItem(int id, String eventTitle, String eventStartDate,
String eventEndDate, String eventLocation, int eventFee, int eventViews){
// mEventPromoImage = eventPromoImage;
mId = id;
mEventTitle = eventTitle;
mEventStartDate = eventStartDate;
mEventEndDate = eventEndDate;
mEventLocation = eventLocation;
mEventFee = eventFee;
mEventViews = eventViews;
Log.d("tag","EVENTITEM title EventItem" + mEventTitle);
// Log.d("tag","EVENTITEM startDate EventItem" + mEventStartDate );
// Log.d("tag","EVENTITEM endDate EventItem" + mEventEndDate );
// Log.d("tag","EVENTITEM address EventItem" + mEventLocation);
// Log.d("tag","EVENTITEM fee EventItem" + mEventFee);
}
public int getEventPromoImage() {
return mEventPromoImage;
}
public void setEventPromoImage(int mEventPromoImage) {
this.mEventPromoImage = mEventPromoImage;
}
public int getEventId() {
return mId;
}
public void setEventId(int mId){
this.mId = mId;
}
public String getEventTitle() {
Log.d("tag","getEventTitle() " + mEventTitle);
return mEventTitle;
}
public void setEventTitle(String mEventTitle) {
this.mEventTitle = mEventTitle;
}
public String getEventStartDate() {
return mEventStartDate;
}
public void setEventStartDate(String mEventStartDate) {
this.mEventStartDate = mEventStartDate;
}
public String getEventEndDate(){
return mEventEndDate;
}
public void setEventEndDate(String mEventEndDate){
this.mEventEndDate = mEventEndDate;
}
public String getEventLocation() {
return mEventLocation;
}
public void setEventLocation(String mEventLocation) {
this.mEventLocation = mEventLocation;
}
public int getEventFee() {
return mEventFee;
}
public void setEventFee(int mEventFee) {
this.mEventFee = mEventFee;
}
public int getEventViews(){
return mEventViews;
}
public void getEventViews(int mEventViews) {
this.mEventViews = mEventViews;
}
public ArrayList<EventItem> getRecyclerList(){
ArrayList event = new ArrayList();
event.add(mEventTitle);
event.add(mEventStartDate);
event.add(mEventEndDate);
event.add(mEventLocation);
event.add(mEventFee);
event.add(mEventViews);
return event;
}
}
EventBackgroundWorker
public class EventBackgroundWorker extends AsyncTask<String, Void, String> {
Context context;
AlertDialog alert;
public static final String REQUEST_URL = "http://10.0.2.2/m/event/";
public EventBackgroundWorker(Context ctxt) {
context = ctxt;
}
//Invoked on UI thread before doInBackground is called
#Override
protected void onPreExecute() {
alert = new AlertDialog.Builder(context).create();
alert.setTitle("Result from server");
}
#Override
protected String doInBackground(String... params) {
String type = params[0];//eventList
//String login_url = "http://10.0.2.2/m/event/";
if(type.equals("event")){
try {
String user_name = params[1];
URL url = new URL(REQUEST_URL);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
httpURLConnection.connect();//works without this connect Find out why
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
String post_data = URLEncoder.encode("getEvents", "UTF-8");
bufferedWriter.write(post_data);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
//read response
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "iso-8859-1"));
String result = "";
String line;
while((line = bufferedReader.readLine()) != null){
result += line;
}
//parse JSON event Array
// Create an empty ArrayList that we can start adding events to
ArrayList<EventItem> eventArray = new ArrayList<>();
JSONArray baseJsonResponse = new JSONArray(result);
for(int i =0; i < baseJsonResponse.length(); i++){
JSONObject event = baseJsonResponse.getJSONObject(i);
int id = event.getInt("id");
String title = event.getString("title");
String address = event.getString("address");
String startDate = event.getString("startDate");
String endDate = event.getString("endDate");
int fee = event.getInt("fee");
int views = event.getInt("views");
//Send data to eventItem Object
EventItem eventObject = new EventItem(id,title,address,startDate,endDate,fee,views);
eventArray.add(eventObject);
/* Log.d("tag", "JSON id " + id);
Log.d("tag", "JSON title " + title);
Log.d("tag", "JSON address " + address);
Log.d("tag", "JSON startDate " + startDate);
Log.d("tag", "JSON endDate " + endDate);
Log.d("tag", "JSON fee " + fee);
Log.d("tag", "JSON views " + views);*/
}
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
return result;
} catch (MalformedURLException e) {//added for URL object
e.printStackTrace();
} catch (IOException e) {
//HTPURLConnection
} catch (JSONException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
//results from doInBackground are passed here
#Override
protected void onPostExecute(String result) {
Log.d("tag", "onPostExecute called" + result);
alert.setMessage(result);
alert.show();
}
}

The AsyncTask creates eventArray but does nothing with it. doInBackground() should return the eventArray and onPostExecute() should set it as adapter content (by a Callback or by setting the Adapter instance at the AsyncTask object). Your Adapter should have a setter for the content which should call notifyDataSetChanged().

android recyclerview load more item upon scrolling using volley

Please help me out to load more data from the server upon scrolling my RecyclerView . Here I have successfully created RecyclerView by loading data from my Mysql server by using volley string request.
Here is my code.
private void populateRecycleView() {
if (Utility.checkNetworkConnection(this)) {
final ProgressDialog progressDialog = new ProgressDialog(this);
progressDialog.setTitle("Searching...");
progressDialog.setMessage("Searching for the blood donor. Please wait a moment.");
progressDialog.setCancelable(false);
progressDialog.show();
StringRequest stringRequest = new StringRequest(Request.Method.POST, Constants.GET_DONORS_URL,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
progressDialog.dismiss();
try {
JSONArray jsonArray = new JSONArray(response);
int count = 0;
while (count < jsonArray.length()) {
JSONObject jsonObject = jsonArray.getJSONObject(count);
String firstName = jsonObject.getString("fName");
String secondName = jsonObject.getString("sName");
String email = jsonObject.getString("emailid");
String password = jsonObject.getString("pass");
String mobile = jsonObject.getString("mobile");
String bloodRt = jsonObject.getString("blood");
String age = jsonObject.getString("age");
String gender = jsonObject.getString("gender");
String country = jsonObject.getString("country");
String location = jsonObject.getString("location");
String latitude = jsonObject.getString("latitude");
String longitude = jsonObject.getString("longitude");
String profilePicFIleName = jsonObject.getString("picname");
String profilePicURL = jsonObject.getString("pic");
Donor donor = new Donor(firstName, secondName, email, password, mobile, bloodRt, age, gender,
country, location, latitude, longitude, profilePicFIleName, profilePicURL);
donorsList.add(donor);
count++;
}
donorsAdapter = new DonorsAdapter(FindDonorResult.this, donorsList);
recyclerView = (RecyclerView) findViewById(R.id.rv_search_result_donor);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(FindDonorResult.this));
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(donorsAdapter);
donorsAdapter.notifyDataSetChanged();
} catch (JSONException e) {
e.printStackTrace();
}
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
progressDialog.dismiss();
Toast.makeText(FindDonorResult.this, "Active data network is not available.", Toast.LENGTH_LONG).show();
}
}
) {
#Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String, String> params = new HashMap<>();
params.put("bloodGroup", bloodGroup);
return params;
}
};
NetworkRequestSingleTon.getOurInstance(this).addToRequestQue(stringRequest);
} else {
Utility.checkNetworkConnectionFound(this);
}
}
And this is my RecyclerView adapter...
public class DonorsAdapter extends RecyclerView.Adapter<DonorsAdapter.CustomViewHolder> {
private Context context;
private ArrayList<Donor> donorList;
private String bloodGroup;
public DonorsAdapter(Context context, ArrayList<Donor> donorList) {
this.context = context;
this.donorList = donorList;
}
#Override
public CustomViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.rv_blood_donors_result,
parent, false);
return new CustomViewHolder(view);
}
#Override
public void onBindViewHolder(CustomViewHolder holder, int position) {
final Donor donor = donorList.get(position);
String displayName = donor.getFirstName() + " " + donor.getSecondName();
holder.tvDisplayName.setText(displayName);
holder.tvEmailID.setText(donor.getEmail());
String userProfileURL = donor.getProfilePicURL();
if (!userProfileURL.equals("")) {
Picasso.with(context).load(userProfileURL).resize(80, 80).centerCrop().
into(holder.ivProfilePic);
} else {
holder.ivProfilePic.setImageResource(R.drawable.ic_person_white_24dp);
}
bloodGroup = donor.getBloodGroup();
if (bloodGroup.equals("A+"))
holder.ivBloodTypeDisplay.setImageResource(R.drawable.a_);
else if (bloodGroup.equals("A-"))
holder.ivBloodTypeDisplay.setImageResource(R.drawable.a_negative);
else if (bloodGroup.equals("B+"))
holder.ivBloodTypeDisplay.setImageResource(R.drawable.b_positive);
else if (bloodGroup.equals("B-"))
holder.ivBloodTypeDisplay.setImageResource(R.drawable.b_negative);
else if (bloodGroup.equals("O+"))
holder.ivBloodTypeDisplay.setImageResource(R.drawable.o_positive);
else if (bloodGroup.equals("O-"))
holder.ivBloodTypeDisplay.setImageResource(R.drawable.o_negative);
else if (bloodGroup.equals("AB+"))
holder.ivBloodTypeDisplay.setImageResource(R.drawable.ab_positive);
else if (bloodGroup.equals("AB-"))
holder.ivBloodTypeDisplay.setImageResource(R.drawable.ab_negative);
if(Utility.isNetworkEnabled){
holder.constraintLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(context, DisplayDonorDetails.class);
intent.putExtra("donor", donor);
context.startActivity(intent);
}
});
}else {
Toast.makeText(context, "Network not available.", Toast.LENGTH_SHORT).show();
}
}
#Override
public int getItemCount() {
if(donorList != null){
return donorList.size();
}else {
return 0;
}
}
public class CustomViewHolder extends RecyclerView.ViewHolder {
ImageView ivProfilePic, ivBloodTypeDisplay, ivArrow;
TextView tvDisplayName;
TextView tvEmailID;
ConstraintLayout constraintLayout;
public CustomViewHolder(View itemView) {
super(itemView);
ivProfilePic = (ImageView) itemView.findViewById(R.id.civ_user_profile_picture);
ivBloodTypeDisplay = (ImageView) itemView.findViewById(R.id.civ_user_blood_type_display);
ivArrow = (ImageView) itemView.findViewById(R.id.civ_arrow);
tvDisplayName = (TextView) itemView.findViewById(R.id.tvUserNameOnRV);
tvEmailID = (TextView) itemView.findViewById(R.id.tvEmailDisplayOnRV);
constraintLayout = (ConstraintLayout) itemView.findViewById(R.id.recycle_view_item_container);
}
}
}

Populate your donorsAdapter only with the 50 first elements of your donorsList, create a function that save the position of the latest element displayed and add other 50 donors to your adapter starting from the latest position saved when you need it.
Hope it helps.
EDIT
First create an emptyList:
List<Donor> subElements = new ArrayList<>();
and pass it to your adapter:
donorsAdapter = new DonorsAdapter(FindDonorResult.this, subElements);
Now you can create a method like this (you can call in onClick event for example):
private int LAST_POSITION = 0;
private int DONORS_NUM_TOSHOW = 50;
public void showMoreDonors(){
if(donarsList.size() > Last_postion+50){
List<Donor> tempList = new ArrayList<Donor>(donorsList.subList(Last_postion,Last_postion+DONORS_NUM_TOSHOW));
for(Donor a : tempList){
subElements.add(a);
}
Last_postion += DONORS_NUM_TOSHOW;
donorsAdapter.notifyDataSetChanged();
}else{
List<Donor> tempList = new ArrayList<Donor>(donorsList.subList(Last_postion,donorsList.size()));
for(Donor a : tempList){
subElements.add(a);
}
donorsAdapter.notifyDataSetChanged();
}
}
Remember to check when donorsList is over.
I didn't test it, but i hope it is usefull to understand the idea.

Finally, I sort this out. I have got an awesome tutorial from this blog.
http://android-pratap.blogspot.in/2015/06/endless-recyclerview-with-progress-bar.html.
I made some changes to populate the list because my data is on a remote server and by using volley library I fetched the data into the list. Remaining things are same.

Return button to previous activity with BaseAdapter

I currently have two activities doing HTTP requests.
The first activity contains a CustomList class extends BaseAdapter.
On the second, there is a previous button allowing me to return to the first activity.
Returning to the first activity, I would like to be able to recover the state in which I left it. That is to say to be able to find the information which also come from an HTTP request. I would like to find the data "infos_user" which is in the first activity and all the data in the BaseAdapter.
My architecture is as follows: Activity 0 (HTTP request) -> Activity 1 (with BaseAdapter and HTTP request) -> Activity 2 (HTTP request)
I put all the code because I really don't know how can I do this :/
First activity:
public class GetChildrenList extends AppCompatActivity implements View.OnClickListener {
private ArrayList<Child> childrenImeList = new ArrayList<Child>();
private Button btn_previous;
private ListView itemsListView;
private TextView tv_signin_success;
int id = 0;
String infos_user;
String email;
String password;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.get_children_list);
infos_user = (String) getIntent().getSerializableExtra("infos_user");
Intent intent = new Intent(GetChildrenList.this , GetLearningGoalsList.class);
intent.putExtra("username", infos_user);
btn_previous = (Button) findViewById(R.id.btn_previous);
btn_previous.setOnClickListener(this);
tv_signin_success = (TextView) findViewById(R.id.tv_signin_success);
tv_signin_success.setText("Bonjour " + infos_user + "!");
itemsListView = (ListView)findViewById(R.id.list_view_children);
new GetChildrenAsync().execute();
}
class GetChildrenAsync extends AsyncTask<String, Void, ArrayList<Child>> {
private Dialog loadingDialog;
#Override
protected void onPreExecute() {
super.onPreExecute();
loadingDialog = ProgressDialog.show(GetChildrenList.this, "Please wait", "Loading...");
}
#Override
protected ArrayList<Child> doInBackground(String... params) {
int age = 0;
email = (String) getIntent().getSerializableExtra("email");
password = (String) getIntent().getSerializableExtra("password");
String first_name = null;
String last_name = null;
try {
SendRequest sr = new SendRequest();
String result = sr.sendHttpRequest("http://" + sr.getIP_ADDRESS() + "/childrenime/list", "GET", true, email, password);
String jsonResult = "{ \"children\":" + result + "}";
Log.d("result1", jsonResult);
//Manage JSON result
JSONObject jsonObject = new JSONObject(jsonResult);
JSONArray childrenArray = jsonObject.getJSONArray("children");
for (int i = 0; i < childrenArray.length(); ++i) {
JSONObject child = childrenArray.getJSONObject(i);
id = child.getInt("id");
first_name = child.getString("first_name");
last_name = child.getString("last_name");
age = child.getInt("age");
String name = first_name + " " + last_name;
childrenImeList.add(new Child(id,name,age));
}
} catch (JSONException e) {
e.printStackTrace();
}
return childrenImeList;
}
#Override
protected void onPostExecute(final ArrayList<Child> childrenListInformation) {
loadingDialog.dismiss();
if(childrenListInformation.size() > 0) {
CustomListChildrenAdapter adapter = new CustomListChildrenAdapter(GetChildrenList.this, childrenListInformation);
itemsListView.setAdapter(adapter);
}
else{
Toast.makeText(getApplicationContext(), "Impossible de récupérer la liste des enfants", Toast.LENGTH_LONG).show();
}
}
}
}
BaseAdapter:
public class CustomListChildrenAdapter extends BaseAdapter implements View.OnClickListener {
private Context context;
private ArrayList<Child> children;
private Button btnChoose;
private TextView childrenName;
private TextView childrenAge;
public CustomListChildrenAdapter(Context context, ArrayList<Child> children) {
this.context = context;
this.children = children;
}
#Override
public int getCount() {
return children.size(); //returns total item in the list
}
#Override
public Object getItem(int position) {
return children.get(position); //returns the item at the specified position
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
View view;
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = inflater.inflate(R.layout.layout_list_view_children,null);
childrenName = (TextView)view.findViewById(R.id.tv_childrenName);
childrenAge = (TextView) view.findViewById(R.id.tv_childrenAge);
btnChoose = (Button) view.findViewById(R.id.btn_choose);
btnChoose.setOnClickListener(this);
} else {
view = convertView;
}
btnChoose.setTag(position);
Child currentItem = (Child) getItem(position);
childrenName.setText(currentItem.getChildName());
childrenAge.setText(currentItem.getChildAge() + "");
return view;
}
#Override
public void onClick(View v) {
Integer position = (Integer) v.getTag();
Child item = (Child) getItem(position);
String email = (String) ((Activity) context).getIntent().getSerializableExtra("email");
String password = (String) ((Activity) context).getIntent().getSerializableExtra("password");
Intent intent = new Intent(context, GetLearningGoalsList.class);
intent.putExtra("idChild",item.getId());
intent.putExtra("email",email);
intent.putExtra("password",password);
context.startActivity(intent);
}
}
Second Activity:
public class GetLearningGoalsList extends AppCompatActivity implements View.OnClickListener {
private ArrayList<LearningGoal> childrenLearningList = new ArrayList<LearningGoal>();
private Button btn_previous;
private ListView itemsListView;
String email;
String password;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.get_learning_goals_list);
btn_previous = (Button) findViewById(R.id.btn_previous);
btn_previous.setOnClickListener(this);
itemsListView = (ListView)findViewById(R.id.list_view_learning_goals);
new GetLearningGoalsAsync().execute();
}
#Override
public void onClick(View v) {
Intent myIntent = new Intent(GetLearningGoalsList.this, GetChildrenList.class);
myIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(myIntent);
return;
}
class GetLearningGoalsAsync extends AsyncTask<String, Void, ArrayList<LearningGoal>> {
private Dialog loadingDialog;
#Override
protected void onPreExecute() {
super.onPreExecute();
loadingDialog = ProgressDialog.show(GetLearningGoalsList.this, "Please wait", "Loading...");
}
#Override
protected ArrayList<LearningGoal> doInBackground(String... params) {
int id = 0;
email = (String) getIntent().getSerializableExtra("email");
password = (String) getIntent().getSerializableExtra("password");
int idChild = (int) getIntent().getSerializableExtra("idChild");
String name = null;
String start_date = null;
String end_date = null;
try {
List<BasicNameValuePair> parameters = new LinkedList<BasicNameValuePair>();
parameters.add(new BasicNameValuePair("idchild", Integer.toString(idChild)));
SendRequest sr = new SendRequest();
String result = sr.sendHttpRequest("http://" + sr.getIP_ADDRESS() + "/learningchild/list"+ "?"+ URLEncodedUtils.format(parameters, "utf-8"), "POST", true, email, password);
String jsonResult = "{ \"learningGoals\":" + result + "}";
Log.d("result1", jsonResult);
//Manage JSON result
JSONObject jsonObject = new JSONObject(jsonResult);
JSONArray learningGoalsArray = jsonObject.getJSONArray("learningGoals");
for (int i = 0; i < learningGoalsArray.length(); ++i) {
JSONObject learningGoal = learningGoalsArray.getJSONObject(i);
id = learningGoal.getInt("id");
name = learningGoal.getString("name");
start_date = learningGoal.getString("start_date");
end_date = learningGoal.getString("end_date");
childrenLearningList.add(new LearningGoal(id,name,start_date,end_date));
}
} catch (JSONException e) {
e.printStackTrace();
}
return childrenLearningList;
}
#Override
protected void onPostExecute(final ArrayList<LearningGoal> learningListInformation) {
loadingDialog.dismiss();
if(learningListInformation.size() > 0) {
CustomListLearningGoalAdapter adapter = new CustomListLearningGoalAdapter(GetLearningGoalsList.this, learningListInformation);
itemsListView.setAdapter(adapter);
}
else{
Toast.makeText(getApplicationContext(), "Impossible de récupérer la liste des scénarios de cet enfant", Toast.LENGTH_LONG).show();
}
}
}
}
Thanks for your help.

if you want to maintain GetChildrenList state as it is then just call finish() rather than new intent on previous button click as follow
replace in GetLearningGoalsList
#Override
public void onClick(View v) {
Intent myIntent = new Intent(GetLearningGoalsList.this, GetChildrenList.class);
myIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(myIntent);
return;
}
with
#Override
public void onClick(View v) {
finish();
}

Transaction ID set correctly, but displayed only a submit later

My code gives correct response and sets transaction ID correctly. But on screen, the ID is missing the first time I submit, and when I go back and submit again, then the ID on screen is the ID of the first transaction.
On the first submit, this is rendered:
MOBILE NUMBER: 9129992929
OPERATOR: AIRTEL
AMOUNT: 344
TRANSACTION ID:
On the second submit, this is rendered:
MOBILE NUMBER: 9129992929
OPERATOR: AIRTEL
AMOUNT: 344
TRANSACTION ID: NUFEC37WD537K5K2P9WX
I want to see the second screen the first time I submit.
Response to the first submit:
D/TID IS: ====>NUFEC37WD537K5K2P9WX D/UID IS:
====>27W3NDW71XRUR83S7RN3 D/Response-------: ------>{"tid":"NUFEC37WD537K5K2P9WX","uid":"27W3NDW71XRUR83S7RN3","status":"ok"}
Response to the second submit:
D/TID IS: ====>18R6YXM82345655ZL3E2 D/UID IS:
====>27W3NDW71XRUR83S7RN3 D/Response-------: ------>{"tid":"18R6YXM82345655ZL3E2","uid":"27W3NDW71XRUR83S7RN3","status":"ok"}
The code generating the response:
public class Prepaid extends Fragment implements View.OnClickListener {
Button submit_recharge;
Activity context;
RadioGroup _RadioGroup;
public EditText number, amount;
JSONObject jsonobject;
JSONArray jsonarray;
ArrayList<String> datalist, oprList;
ArrayList<Json_Data> json_data;
TextView output, output1;
String loginURL = "http://www.www.example.com/operator_details.php";
ArrayList<String> listItems = new ArrayList<>();
ArrayAdapter<String> adapter;
String data = "";
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View rootview = inflater.inflate(R.layout.prepaid, container, false);
submit_recharge = (Button) rootview.findViewById(R.id.prepaid_submit);
number = (EditText) rootview.findViewById(R.id.prenumber);
amount = (EditText) rootview.findViewById(R.id.rechergpre);
submit_recharge.setOnClickListener(this);
context = getActivity();
new DownloadJSON().execute();
return rootview;
}
public void onClick(View v) {
MyApplication myRecharge = (MyApplication) getActivity().getApplicationContext();
final String prepaid_Number = number.getText().toString();
String number_set = myRecharge.setNumber(prepaid_Number);
final String pre_Amount = amount.getText().toString();
String amount_set = myRecharge.setAmount(pre_Amount);
Log.d("amount", "is" + amount_set);
Log.d("number", "is" + number_set);
switch (v.getId()) {
case R.id.prepaid_submit:
if (prepaid_Number.equalsIgnoreCase("") || pre_Amount.equalsIgnoreCase("")) {
number.setError("Enter the number please");
amount.setError("Enter amount please");
} else {
int net_amount_pre = Integer.parseInt(amount.getText().toString().trim());
String ph_number_pre = number.getText().toString();
if (ph_number_pre.length() != 10) {
number.setError("Please Enter valid the number");
} else {
if (net_amount_pre < 10 || net_amount_pre > 2000) {
amount.setError("Amount valid 10 to 2000");
} else {
AsyncTaskPost runner = new AsyncTaskPost(); // for running AsyncTaskPost class
runner.execute();
Intent intent = new Intent(getActivity(), Confirm_Payment.class);
startActivity(intent);
}
}
}
}
}
}
/*
*
* http://pastie.org/10618261
*
*/
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
MyApplication myOpt = (MyApplication) getActivity().getApplicationContext();
protected Void doInBackground(Void... params) {
json_data = new ArrayList<Json_Data>();
datalist = new ArrayList<String>();
// made a new array to store operator ID
oprList = new ArrayList<String>();
jsonobject = JSONfunctions
.getJSONfromURL(http://www.www.example.com/operator_details.php");
Log.d("Response: ", "> " + jsonobject);
try {
jsonarray = jsonobject.getJSONArray("data");
for (int i = 0; i < jsonarray.length(); i++) {
jsonobject = jsonarray.getJSONObject(i);
Json_Data opt_code = new Json_Data();
opt_code.setName(jsonobject.optString("name"));
opt_code.setId(jsonobject.optString("ID"));
json_data.add(opt_code);
datalist.add(jsonobject.optString("name"));
oprList.add(jsonobject.getString("ID"));
}
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
protected void onPostExecute(Void args) {
final Spinner mySpinner = (Spinner) getView().findViewById(R.id.operator_spinner);
mySpinner
.setAdapter(new ArrayAdapter<String>(getActivity(),
android.R.layout.simple_spinner_dropdown_item,
datalist));
mySpinner
.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> arg0,
View arg1, int position, long arg3) {
String opt_code = oprList.get(position);
String selectedItem = arg0.getItemAtPosition(position).toString();
Log.d("Selected operator is==", "======>" + selectedItem);
Log.d("Selected Value is======", "========>" + position);
Log.d("Selected ID is======", "========>" + opt_code);
if (opt_code == "8" || opt_code == "14" || opt_code == "35" || opt_code == "36" || opt_code == "41" || opt_code == "43") // new code
{
_RadioGroup = (RadioGroup) getView().findViewById(R.id.radioGroup);
_RadioGroup.setVisibility(View.VISIBLE);
int selectedId = _RadioGroup.getCheckedRadioButtonId();
// find the radiobutton by returned id
final RadioButton _RadioSex = (RadioButton) getView().findViewById(selectedId);
_RadioSex.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if (null != _RadioSex && isChecked == false) {
Toast.makeText(getActivity(), _RadioSex.getText(), Toast.LENGTH_LONG).show();
}
Toast.makeText(getActivity(), "Checked In button", Toast.LENGTH_LONG).show();
Log.d("Checked In Button", "===>" + isChecked);
}
});
}
String user1 = myOpt.setOperator(opt_code);
String opt_name = myOpt.setOpt_provider(selectedItem);
}
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
});
}
}
private class AsyncTaskPost extends AsyncTask<String, Void, Void> {
MyApplication mytid = (MyApplication)getActivity().getApplicationContext();
String prepaid_Number = number.getText().toString();
String pre_Amount = amount.getText().toString();
protected Void doInBackground(String... params) {
String url = "http://www.example.com/android-initiate-recharge.php";
StringRequest postRequest = new StringRequest(Request.Method.POST, url,
new Response.Listener<String>() {
public void onResponse(String response) {
try {
JSONObject json_Response = new JSONObject(response);
String _TID = json_Response.getString("tid");
String _uid = json_Response.getString("uid");
String _status = json_Response.getString("status");
String tid_m =mytid.setTransaction(_TID);
Log.d("TID IS","====>"+tid_m);
Log.d("UID IS", "====>" + _uid);
} catch (JSONException e) {
e.printStackTrace();
}
Log.d("Response-------", "------>" + response);
}
},
new Response.ErrorListener() {
public void onErrorResponse(VolleyError error) {
Log.e("Responce error==","===>"+error);
error.printStackTrace();
}
}
) {
MyApplication uid = (MyApplication) getActivity().getApplicationContext();
final String user = uid.getuser();
MyApplication operator = (MyApplication) getActivity().getApplicationContext();
final String optcode = operator.getOperator();
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<>();
// the POST parameters:
params.put("preNumber", prepaid_Number);
params.put("preAmount", pre_Amount);
params.put("key", "XXXXXXXXXX");
params.put("whattodo", "prepaidmobile");
params.put("userid", user);
params.put("category", optcode);
Log.d("Value is ----------", ">" + params);
return params;
}
};
Volley.newRequestQueue(getActivity()).add(postRequest);
return null;
}
protected void onPostExecute(Void args) {
}
}
class Application
private String _TId;
public String getTId_name() {
return _TId;
}
public String setTId_name(String myt_ID) {
this._TId = myt_ID;
Log.d("Application set TID", "====>" + myt_ID);
return myt_ID;
}
class Confirm_pay
This is where the ID is set.
MyApplication _Rechargedetail =(MyApplication)getApplicationContext();
confirm_tId =(TextView)findViewById(R.id._Tid);
String _tid =_Rechargedetail.getTId_name();
confirm_tId.setText(_tid);

Because you have used Volley library which is already asynchronous, you don't have to use AsyncTask anymore.
Your code can be updated as the following (not inside AsyncTask, direct inside onCreate for example), pay attention to // update TextViews here...:
...
String url = "http://www.example.com/index.php";
RequestQueue requestQueue = Volley.newRequestQueue(this);
StringRequest postRequest = new StringRequest(Request.Method.POST, url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
try {
JSONObject json_Response = new JSONObject(response);
String _TID = json_Response.getString("tid");
String _uid = json_Response.getString("uid");
String _status = json_Response.getString("status");
String tid_m =mytid.setTId_name(_TID);
Log.d("TID IS","====>"+tid_m);
Log.d("UID IS","====>"+_uid);
// update TextViews here...
txtTransId.setText(_TID);
txtStatus.setText(_status);
...
} catch (JSONException e) {
e.printStackTrace();
}
Log.d("Response-------", "------>" + response);
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e("Responce error==","===>"+error);
error.printStackTrace();
}
}
requestQueue.add(postRequest);
...
P/S: since the reponse data is a JSONObject, so I suggest you use JsonObjectRequest instead of StringRequest. You can read more at Google's documentation.
Hope it helps!

Your line of code should be executed after complete execution of network operation and control comes in onPostExecute(); of your AsyncTask.
confirm_tId.setText(_tid);

Develop Reference

The Android operating system is a mobile operating system that was developed by Google (GOOGL?) to be primarily used for touchscreen devices, cell phones, and tablets.

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Best you can do is use http://developer.android.com/reference/java/util/concurrent/ThreadPoolExecutor.html and make a lru cache and place the images in lru cache. Example is given in android tutorials http://developer.android.com/training/displaying-bitmaps/cache-bitmap.html

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