I have url that has a json Array which contains a large amount of data.
I call the url with volly jsonArrayRequest like this
public void makeJsonArrayReq(){
showProgressDialog();
JsonArrayRequest req = new JsonArrayRequest(Const.URL_IPD_ADMITED,
new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
Log.d("response ================", response.toString());
textView.setText(response.toString());
hideProgressDialog();
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d("Error", "Error: " + error.getMessage());
textView.setText("Error Occurs ");
hideProgressDialog();
}
});
AppController.getInstance().addToRequestQueue(req, "array");
}
My devise shows progressDialog for some time after that time it hang out the app then after a few minute it shows the response in the texview but it very lengthy process and it same when internet connection off and extract from volley cache. How can I handle the URL in my apps?
You need to change your api a bit to support pagination. There are several pagination techniques available, you have to choose one that suites your case.
In Android you can save the last fetched pageNumber(if that is what your API returns as page identifier) and your api should accept this variable in request (mostly through query params)
http://43.255.22.123:3000/android/mis/get/ipdAdmitPatMd?pageId=1
And in the next request it should update the pageId to 2.
Since the question is too broad hence providing exact code solution is not possible therefore I have explained the concept.
Related
I am trying to fetch a JSON response from OpenWeatherAPI to incorporate the current weather in my app. I have used volley to make a simple request to fetch the JSON response, but every time, I do not get the response. Instead, it always triggers the onErrorResponse method. What do I change to make this work?
I have added the uses Internet Permission in my manifest.
I have tried the solution to fetch JSON responses from many sources including the Official Android Developers Documentation, Other Questions from Stack Overflow, etc, but all of them failed.
I first used JSONObjectRequest instead of StringRequest, but even that did not provide me the results I required.
/*
Create a request queue to fetch the JSONObject response.
*/
RequestQueue queue = Volley.newRequestQueue(Objects.requireNonNull(getContext()));
/*
JSON Object request.
*/
StringRequest request = new StringRequest(Request.Method.GET, url, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Toast.makeText(getContext(), response, Toast.LENGTH_SHORT).show();
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(getContext(), "No JSON", Toast.LENGTH_SHORT).show();
}
});
queue.add(request);
I expect the Toast to show the response, but The Toast shows "No JSON".
Add "https://" before your URL. You will get a response on your browser, but will not in Android.
I have made a splash screen where im syncing data from server to sqlite. I have to make few requests (lets say 5 request for 5 tables), and then the splash screen goes off and main activity starts. Please share some ideas as Im clueless how to achieve this. I have left no stone unturned in stackoverflow but could not find a perfect workaround.
Add Volley https://stackoverflow.com/questions/16659620/volley-android-networking-library?rq=1
Then you can make calls from volley
JsonObjectRequest jsonObjReq = new JsonObjectRequest(com.android.volley.Request.Method.POST, Url__, ipObject,
new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
listener.resultJson(null, response);
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
}
listener.resultJson(null, response); will get the responce from server and save this responce to your Sqlite.Finally close your Spalsh .
I have to make several requests to an API for an Android App and I am having the following problem:
I have a list of items and I have to make a request for each in order to get some data and show it in the app. When my list's size is 1 (in case I have only one item), the app works perfectly but if I have more I get the data mixed and one item have the value of other and things like that.
I am using JsonObjectRequest and Volley. I use callback interfaces for sending back the request data to the activities. I think it's probably a synchronisation problem but I'm not sure and I'm a bit frustrated. I've tried everything!
Request Code:
JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, urlMarket, null, new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
try {
JSONObject singleResult;
singleResult = response.getJSONArray("result").getJSONObject(0);
coin.setHigh(singleResult.getDouble("High"));
coin.setLow(singleResult.getDouble("Low"));
coin.setLast(singleResult.getDouble("Last"));
coin.setVolInBtc(singleResult.getDouble("BaseVolume"));
coin.setBid(singleResult.getDouble("Bid"));
coin.setAsk(singleResult.getDouble("Ask"));
coin.setPrevDay(singleResult.getString("PrevDay"));
callback.onSuccess(coin);
} catch (Exception e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
error.printStackTrace();
}
});
requestQueue.add(request);
Any kind of help would be appreciated!!
PD.: if there's a better way for doing that instead of JsonObjectRequest, please tell me!
Consider either of these two options:
Extend JSONObjectRequest that accepts a id/token field which is returned as part of the Success/Error callback.
Use a final field as an identifier before you make an API call. Assuming you are making these calls in a loop, you can then refer to this final field from your anonymous callbacks to identify the specific Stock. For example, you can use the ISIN, database ID or ticker symbol to identify the response.
In my application i need to display the data in list view from rest service . I have gone through many samples but am not satisfied with that so can somebody help me ? Need sample or explanation . Thanks in advance!
In android you can use libraries to consuming REST
Volley
Retrofit
Your question is very general. Try one from above.
Sample use Volley:
in gradle: compile 'com.mcxiaoke.volley:library:1.0.19'
// Instantiate the RequestQueue.
RequestQueue queue = Volley.newRequestQueue(this);
String url ="http://www.google.com";
// Request a string response from the provided URL.
StringRequest stringRequest = new StringRequest(Request.Method.GET, url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
// Display the first 500 characters of the response string.
mTextView.setText("Response is: "+ response.substring(0,500));
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
mTextView.setText("That didn't work!");
}
});
// Add the request to the RequestQueue.
queue.add(stringRequest);
you can call api in fragments.
if you are new to android,
1)first fetch the data from api with a asynctask(check android json parsing with url in learn2crack).
2)after step 1 you have your data to populate to your list,if you want to make a custom list the same site also gives an example for android custom list(learn2crack)
you can call json on asynctask class.
call the async task in onCrateView of your fragment
I have used Android Volley library for loading and caching of data coming from a server. The following is the simple code I used.
// Creating volley request queue
RequestQueue queue = Volley.newRequestQueue(getActivity());
// Creating volley request obj
JsonArrayRequest mReq = new JsonArrayRequest(url,
new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
Log.d(TAG, response.toString());
hidePDialog();
progressBar.setVisibility(View.GONE);
// update the data fetched from server
if(mList != null)
{
mList.clear();
}
parseVolleyResponse(response);
// notifying list adapter about data changes
// so that it renders the list view with updated data
rAdapter.notifyDataSetChanged();
Log.d("notifyDataSetChanged", "notifyDataSetChanged");
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
// TODO Auto-generated method stub
VolleyLog.d(TAG, "Error: " + error.getMessage());
hidePDialog();
}
});
// Adding volley request to the queue
queue.add(mReq);
The loading and caching are working fine. Now, I want to display a message like "15 new data available. Tap to load." at the top of my layout whenever new data is available at server end i.e. I want to notify whenever new data is available along with its length. How can I do that? Should I use this Entry entry = queue.getCache().get(url); to check the difference between cache and network? Please help with the coding.