Android Where to start Activity in MVVM Resarlt - java

I supposed to use MVVM pattern with Data Repository. Data Came from Web Api call. and based on The Data, The Application Start The Web Browser With Returned URL.
on user interaction The Activity calls ViewModel Which owns Data:
CheckOutActivity.java:
MaterialRippleLayout makeOrder = findViewById(R.id.btn_make_order);
makeOrder.setOnClickListener(view ->{
viewModel.makeOrder();
});
viewModel calls DataRepository with Appropriate Data (optionalShippingEntityIds) to call Web Api Async:
CheckOutViewModel.java
public void makeOrder(){
cartRepository.makeOrder(optionalShippingEntityIds.getValue());
}
The Repository has been instantiated before:
public CheckOutViewModel(#NonNull Application application) {
super(application);
cartRepository = new CartRepository(application);
}
in DataRepository Api Call performs:
CartRepository
public void makeOrder(ArrayList<Integer> optionalShippingEntityIds){
HashMap<String,String> map = new HashMap<String,String>();
String idsString=optionalShippingEntityIds.toString();
map.put("shipment_saleitem_id",idsString);
rest.httpRequest(RestAdapter.HttpVerb.POST,"order",map,new makeOrderHandler());
}
The CartRepository Constructor:
private RestAdapter rest;
private Context context;
public CartRepository(Context context) {
this.context = context;
rest = RestAdapter.getInstance(context);
version.setValue(0);
}
4.HttpResponseHandler Handle The Web Browser open URL or Toast fail message
CartRepository.java
class makeOrderHandler extends JsonHttpResponseHandler{
#Override
public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
if(statusCode == 200){
try {
Toast.makeText(context,"order number "+response.getInt("order_id")+"has been created",Toast.LENGTH_SHORT).show();
String redirectUrl = response.getString("init_payment_url");
version.setValue(version.getValue() +1);
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(redirectUrl));
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(intent);
((Activity)context).finishAffinity();
//System.exit(0);
/*Intent chooserIntent = Intent.createChooser(intent, "Open With");
chooserIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(chooserIntent);*/
}
}, 2000);
} catch (JSONException e) {
Toast.makeText(context,"JSON parse error"+" : "+response.toString(), Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
}else{
Log.e("server api changed ", "error in getting response using known api \n" + response.toString());
Toast.makeText(context,"api change",Toast.LENGTH_SHORT).show();
}
}
#Override
public void onFailure(int statusCode, Header[] headers, String res, Throwable t) {
// called when response HTTP status is "4XX" (eg. 401, 403, 404)
Log.e("server 500", "error in getting response using async-apache-http call"+" : "+res);
t.printStackTrace();
Toast.makeText(context, "خطا سرور ", Toast.LENGTH_SHORT).show();
}
#Override
public void onFailure(int statusCode, Header[] headers, Throwable t, JSONObject e) {
if(statusCode == 504){
Toast.makeText(context,"The Order hasnt been created duo to internal problem. please try again",Toast.LENGTH_SHORT).show();
}else{
Log.e("server api changed", "error in getting response using known api \n" + e.toString());
t.printStackTrace();
Toast.makeText(context,"Api is unknown",Toast.LENGTH_SHORT).show();
}
}
}
The Problem is after i launch The Application in some Devices, in The Line ((Activity)context).finishAffinity(); The Application Crashes because The context is an application context instance and not an activity context instance .
if i pass The Activity instance Through ViewModel, i had just violated The MVVM.
if i make an interface in The Activity and implement it. it violates The Activity Single Responsibility (Data Repository Response Handler Should Handle The startActivity)
so i dont know how to handle this perfectly.
if i eliminate The ViewModel makeOrder, and Construct The Repository With The Activity Context I think its ViewModel Responsibility to Handle The Data Manipulation Job.
....
So I am Confused With The Right Solution To Handling StartActivity and Toast in Response.
if anyone could help me With The Right Design Pattern i Would Appreciate.

Your viewmodel can extends from AndroidViewModel.
From documentation:
"Application context aware ViewModel.
Subclasses must have a constructor which accepts Application as the only parameter."

Related

How to upload Multiple Images using Array List in android

I try many solutions but no once work for me.
I'm receiving images data in this way:
ArrayList<String> filePaths = data.getStringArrayListExtra(Pix.IMAGE_RESULTS);
and uploading images using multipart
MultipartBody requestBody = builder.build();
Call<Status_Response> call = taskMetServer.uploadMultiplePics(requestBody.parts());
call.enqueue(new Callback<Status_Response>() {
#Override
public void onResponse(Call<Status_Response> call, Response<Status_Response> response) {
if(response.isSuccessful()){
Status_Response status_response = response.body();
assert status_response != null;
String msg = status_response.getStatus();
Log.d("myMessage", "\n\nStatus: "+msg);
progressBar.setVisibility(View.GONE);
Toast.makeText(getContext(), "Success " + response.message()+response.code(), Toast.LENGTH_LONG).show();
}
}
#Override
public void onFailure(Call<Status_Response> call, Throwable t) {
progressBar.setVisibility(View.GONE);
Toast.makeText(getContext(), t.getMessage(), Toast.LENGTH_SHORT).show();
}
});
}
my interface is:
#POST("test/store")
Call<Status_Response> uploadMultiplePics(
#Body List<MultipartBody.Part> images
);
but still receiving null in response instead of true of false:
2021-03-20 17:36:38.076 10582-10582/com.example.ourproductapp D/myMessage: [/storage/emulated/0/WhatsApp/Media/WhatsApp Images/IMG-20210320-WA0082.jpeg]
2021-03-20 17:36:38.732 10582-10582/com.example.ourproductapp D/myMessage: Status: null
Thanks in advance
check your backend service, your server is getting file or not.
or you can use https://github.com/gotev/android-upload-service library

How can I return a value from a function that uses json response?

I have implemented function to get the restaurant area minimum order. In check_minimum_order() function, I have got desired result from the response. The value is rest_area_min_order = 10. Now, I want to pass the value which I received through JSON to the next function So that I can do calculation part.
Here is the code of check_minimum_order()
private void check_minimum_order(String restaurant_id)
{
try
{
String url;
if(appPrefs.getLanguage().equalsIgnoreCase("ar"))
url = LinksConstants.BASE_URL
+ LinksConstants.CHECK_MINIMUM_ORDER;
else
url = LinksConstants.BASE_URL
+ LinksConstants.CHECK_MINIMUM_ORDER;
RequestParams params = new RequestParams();
params.put("restaurant_id", restaurant_id);
params.put("area_id", city_id);
NetworkRestClient.post(url, params, new JsonHttpResponseHandler() {
#Override
public void onStart() {
super.onStart();
progressActivity.showLoading();
}
#Override
public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
super.onSuccess(statusCode, headers, response);
try
{
if (response != null)
{
rest_area_min_order = response.getString("restaurant_area_min_order");
}
}
catch (Exception ex)
{
GSLogger.e(ex);
showError();
}
}
#Override
public void onFailure(int statusCode, Header[] headers, String errorResponse, Throwable throwable) {
super.onFailure(statusCode, headers, errorResponse, throwable);
showError();
if(AppConstants.DEBUG_MODE)
showToast(errorResponse);
}
#Override
public void onFailure(int statusCode, Header[] headers, Throwable throwable, JSONObject errorResponse) {
super.onFailure(statusCode, headers, throwable, errorResponse);
showError();
}
});
}
catch (Exception ex)
{
GSLogger.e(ex);
showError();
}
}
Now, the above check_minimum_order() function gave me the value of rest_area_min_order as 10. Now, I want to use this rest_area_min_order in another function. Here is the code: `
check_minimum_order(restaurant_id);
HashMap<String, Object> items_hash = (HashMap<String, Object>) rest_cart_hash.get(restaurant.getId());
items_hash.put("delivery_pickup_time", time);
items_hash.put("pickup_address_id", pickup_id);
items_hash.put("payment_method_id", payment_id);
items_hash.put("delivery_pickup", delivery_pickup);
items_hash.put("selected_user_address_id", user_address_id);
items_hash.put("rest_area_min_order", rest_area_min_order);
restaurantList.add(items_hash);
String rest_min_order = (String) items_hash.get("rest_min_order");
String rest_subtotal = (String) items_hash.get("rest_subtotal");
String rest_area_min_order = (String) items_hash.get("rest_area_min_order");
boolean isError = isValidMinOrderAmount(rest_min_order, rest_subtotal, rest_area_min_order);`
Basically your onSuccess function return void so you cannot return anything. You can simply call another function in onSuccess (For example setMinimumOrder(int pMinimumOrder)) which will take rest_area_min_order as a input and you can perform rest of the things as per your requirement.
As Far as I know, there are two options to achieve this.
1) Put the code to be executed, directly in onSuccess after getting the value of rest_area_min_order. Or you can create a separate method for that.
2) Using Interface to pass value.
I prefer the first option which is very simple.
From your question, I understand that you have to do some calculation after getting web service response. If the rest of calculation needs to done in same class then call that method after getting response
if (response != null)
{
rest_area_min_order = response.getString("restaurant_area_min_order");
doPostCalculations(rest_area_min_order);
}
If check_minimum_order() method is in Network class and you are calling this method from another class (eg: activity), then you can communicate back to activity(or the class that called the method) using interface on getting the response.
Here is a sample interface that you can use.
public interface ApiListener {
void onSuccess(JSONObject response);
void onFailure();
}
Please have a look at this post for getting more idea about interface - How to create our own Listener interface in android?
The main reason is that in your check_minimum_order method you post your networking to another thread if you wan to do some work with the result returned from network then you must call it in on success after the result is really fetched.

AsyncHttpClient android internet issue

I’m new in android programming and for testing I have this code that download google home page.
The code works but I have a problem :
if I start app and internet is ok , code download without problem the page but if , for example , during download internet falls I have no way of knowing because no method will call.
How do I solve this problem?
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
AsyncHttpClient client = new AsyncHttpClient();
client.get("https://www.google.com", new AsyncHttpResponseHandler() {
#Override
public void onStart() {
// called before request is started
Log.d ("info", "PRIMA DELLA CONNESSIONE");
}
#Override
public void onSuccess(int statusCode, Header[] headers, byte[] response) {
// called when response HTTP status is "200 OK"
Log.d ("info", "DATI");
Log.d ("info", response.toString());
}
#Override
public void onFailure(int statusCode, Header[] headers, byte[] errorResponse, Throwable e) {
// called when response HTTP status is "4XX" (eg. 401, 403, 404)
Log.d ("info", "errore");
Log.d ("info", Integer.toString(statusCode));
}
#Override
public void onRetry(int retryNo) {
// called when request is retried
Log.d ("info", "RETRY");
}
});
}
thats rigth thats how it works, but i think there is a method called,
onFinish, and you can set the request time, for some error of network connection you can put your code inside a try-catch
try
{
//your code here
}
catch(Exceptio e) // you can try catch SocketException
{}
with try you can catch if there is some error in your connection

Robospice exception never caught in RequestListener

I have an android app which uses Robospice with Google HTTP client to send RESTful request to a server.
All works fine if result is successfully returned but if an exception is returned from my service, the Robospice listener doesn't catch the exception.
public final class FBUserSaveListener implements RequestListener<HttpResponse> {
#Override
public void onRequestFailure( SpiceException spiceException ) {
if(progressDialog.isShowing())
{
progressDialog.dismiss();
}
Toast.makeText(getActivity(),
"Error: " + spiceException.getMessage(), Toast.LENGTH_SHORT)
.show();
Intent i = new Intent(getActivity(), ErrorActivity.class);
startActivity(i);
}
#Override
public void onRequestSuccess(HttpResponse response) {
if (progressDialog.isShowing()) {
progressDialog.dismiss();
}
if(response.getStatusCode() == AppConstants.HTTP_CODE_CREATED_201) {
Intent intent = new Intent(getActivity(), PoolMainActivity.class);
startActivity(intent);
}
else{
//Request was sent successfully but the response was wrong
// Redirect to error page
Intent i = new Intent(getActivity(), ErrorActivity.class);
startActivity(i);
}
}
}
In the above code, when the external service returns an exception, the onRequestFailure() is not hit at all.
My request is :
public HttpResponse loadDataFromNetwork() throws Exception{
String url = context.getString(R.string.BASE_SERVICE_URL) + context.getString(R.string.USER_FB_LOGIN_SAVE);
HttpRequest request = getHttpRequestFactory()//
.buildPostRequest(new GenericUrl(url), ByteArrayContent.fromString("application/json", fbLoginBeanJson));
request.setParser(new com.google.api.client.json.jackson2.JacksonFactory().createJsonObjectParser());
return request.execute();
}
Did I miss something in the Robospice implementation of RESTful services ?
I managed to solve this by debugging my fragment's life cycle.
I realized that the spiceManager was getting cleared due to the changes in my fragment's life cycle. Saw the FAQ section in robospice and it helped me a lot.
Made the spiceManager start and end in the onAttach and onDetach methods of my fragment respectively.

Using Retrofit in Android

I have an android app that has 3 activities :
A login activity
A tasks acivity where all tasks pertaining to a user are displayed (Populated using an Array Adapter)
A task_details activity which results from clicking a task on the list
I have to consume REST Apis. The research I have done so far directs me to use Retrofit. I checked how to use it and found out that :
Set the base URL in the Main Activity (Mine is the Login Activity)
I need to create a API class and define my functions using annotations.
Use the class Rest Adapter in the Activity and define Callbacks.
Had my app been a single activity app, I would have crunched everything in my MainActivity.java but I don't know how and where to put all the code from steps 1,2,3 for use in my 3 activities.Could you please help by telling how to use Retrofit in my app. Thanks a lot.
Specifically, I need network calls to :
1. Login the user
2. Get all the tasks of the user.
And for both I would be using a given REST api.
*********************************************
Calling Api USing Retrofit
*********************************************
**Dependancies** :-
implementation 'com.android.support:recyclerview-v7:27.1.1'
implementation 'com.squareup.picasso:picasso:2.5.2'
implementation 'com.android.support:cardview-v7:27.1.1'
enter code here
**Model**
use the Pozo class
**Api Call**
-> getLogin() // use the method
//API call for Login
private void getLogin()
{
getWindow().setFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE,
WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);
AsyncHttpClient client = new AsyncHttpClient();
RequestParams requestParams = new RequestParams();
requestParams.put("email_id", edit_email.getText().toString());
requestParams.put("password", edit_password.getText().toString());
Log.e("", "LOGIN URL==>" + Urls.LOGIN + requestParams);
Log.d("device_token", "Device_ Token" + FirebaseInstanceId.getInstance().getToken());
client.post(Urls.LOGIN, requestParams, new JsonHttpResponseHandler() {
#Override
public void onStart() {
super.onStart();
ShowProgress();
}
#Override
public void onFinish() {
super.onFinish();
Hideprogress();
}
#Override
public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
super.onSuccess(statusCode, headers, response);
Log.e("", "Login RESPONSE-" + response);
Login login = new Gson().fromJson(String.valueOf(response), Login.class);
edit_email.setText("");
edit_password.setText("");
if (login.getStatus().equals("true")) {
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);
MDToast mdToast = MDToast.makeText(SignInActivity.this, String.valueOf("User Login Successfully!"),
MDToast.LENGTH_SHORT, MDToast.TYPE_SUCCESS);
mdToast.show();
Utils.WriteSharePrefrence(SignInActivity.this, Util_Main.Constant.EMAIL, login.getData().getEmailId());
Utils.WriteSharePrefrence(SignInActivity.this, Constant.USERID, login.getData().getId());
Utils.WriteSharePrefrence(SignInActivity.this, Constant.USERNAME, login.getData().getFirstName());
Utils.WriteSharePrefrence(SignInActivity.this, Constant.PROFILE, login.getData().getProfileImage());
hideKeyboard(SignInActivity.this);
Intent intent = new Intent(SignInActivity.this, DashboardActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
finish();
} else {
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);
MDToast mdToast = MDToast.makeText(SignInActivity.this, String.valueOf("Login Denied"),
MDToast.LENGTH_SHORT, MDToast.TYPE_ERROR);
mdToast.show();
}
}
#Override
public void onFailure(int statusCode, Header[] headers, String responseString, Throwable throwable) {
super.onFailure(statusCode, headers, responseString, throwable);
Log.e("", throwable.getMessage());
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);
MDToast mdToast = MDToast.makeText(SignInActivity.this, "Something went wrong",
MDToast.LENGTH_SHORT, MDToast.TYPE_ERROR);
mdToast.show();
}
});
}
Using Retrofit is quite simple and straightforward.
First of all you need to add retrofit to your project, as example with Gradle build sytem.
compile 'com.squareup.retrofit:retrofit:1.7.1' |
another way you can download .jar and place it to your libs folder.
Then you need to define interfaces that will be used by Retrofit to make API calls to your REST endpoints. For example for users:
public interface YourUsersApi {
//You can use rx.java for sophisticated composition of requests
#GET("/users/{user}")
public Observable<SomeUserModel> fetchUser(#Path("user") String user);
//or you can just get your model if you use json api
#GET("/users/{user}")
public SomeUserModel fetchUser(#Path("user") String user);
//or if there are some special cases you can process your response manually
#GET("/users/{user}")
public Response fetchUser(#Path("user") String user);
}
Ok. Now you have defined your API interface an you can try to use it.
To start you need to create an instance of RestAdapter and set base url of your API back-end. It's also quite simple:
RestAdapter restAdapter = new RestAdapter.Builder()
.setEndpoint("https://yourserveraddress.com")
.build();
YourUsersApi yourUsersApi = restAdapter.create(YourUsersApi.class);
Here Retrofit will read your information from interface and under the hood it will create RestHandler according to meta-info your provided which actually will perform HTTP requests.
Then under the hood, once response is received, in case of json api your data will be transformed to your model using Gson library so you should be aware of that fact that limitations that are present in Gson are actually there in Retrofit.
To extend/override process of serialisers/deserialisation your response data to your models you might want to provide your custom serialisers/deserialisers to retrofit.
Here you need to implement Converter interface and implement 2 methods fromBody() and toBody().
Here is example:
public class SomeCustomRetrofitConverter implements Converter {
private GsonBuilder gb;
public SomeCustomRetrofitConverter() {
gb = new GsonBuilder();
//register your cursom custom type serialisers/deserialisers if needed
gb.registerTypeAdapter(SomeCutsomType.class, new SomeCutsomTypeDeserializer());
}
public static final String ENCODING = "UTF-8";
#Override
public Object fromBody(TypedInput body, Type type) throws ConversionException {
String charset = "UTF-8";
if (body.mimeType() != null) {
charset = MimeUtil.parseCharset(body.mimeType());
}
InputStreamReader isr = null;
try {
isr = new InputStreamReader(body.in(), charset);
Gson gson = gb.create();
return gson.fromJson(isr, type);
} catch (IOException e) {
throw new ConversionException(e);
} catch (JsonParseException e) {
throw new ConversionException(e);
} finally {
if (isr != null) {
try {
isr.close();
} catch (IOException ignored) {
}
}
}
}
#Override
public TypedOutput toBody(Object object) {
try {
Gson gson = gb.create();
return new JsonTypedOutput(gson.toJson(object).getBytes(ENCODING), ENCODING);
} catch (UnsupportedEncodingException e) {
throw new AssertionError(e);
}
}
private static class JsonTypedOutput implements TypedOutput {
private final byte[] jsonBytes;
private final String mimeType;
JsonTypedOutput(byte[] jsonBytes, String encode) {
this.jsonBytes = jsonBytes;
this.mimeType = "application/json; charset=" + encode;
}
#Override
public String fileName() {
return null;
}
#Override
public String mimeType() {
return mimeType;
}
#Override
public long length() {
return jsonBytes.length;
}
#Override
public void writeTo(OutputStream out) throws IOException {
out.write(jsonBytes);
}
}
}
And now you need to enable your custom adapters, if it was needed by using setConverter() on building RestAdapter
Ok. Now you are aware how you can get your data from server to your Android application. But you need somehow mange your data and invoke REST call in right place.
There I would suggest to use android Service or AsyncTask or loader or rx.java that would query your data on background thread in order to not block your UI.
So now you can find the most appropriate place to call
SomeUserModel yourUser = yourUsersApi.fetchUser("someUsers")
to fetch your remote data.
I have just used retrofit for a couple of weeks and at first I found it hard to use in my application. I would like to share to you the easiest way to use retrofit in you application. And then later on if you already have a good grasp in retrofit you can enhance your codes(separating your ui from api and use callbacks) and maybe get some techniques from the post above.
In your app you have Login,Activity for list of task,and activity to view detailed task.
First thing is you need to add retrofit in your app and theres 2 ways, follow #artemis post above.
Retrofit uses interface as your API. So, create an interface class.
public interface MyApi{
/*LOGIN*/
#GET("/api_reciever/login") //your login function in your api
public void login(#Query("username") String username,#Query("password") String password,Callback<String> calback); //this is for your login, and you can used String as response or you can use a POJO, retrofit is very rubust to convert JSON to POJO
/*GET LIST*/
#GET("/api_reciever/getlist") //a function in your api to get all the list
public void getTaskList(#Query("user_uuid") String user_uuid,Callback<ArrayList<Task>> callback); //this is an example of response POJO - make sure your variable name is the same with your json tagging
/*GET LIST*/
#GET("/api_reciever/getlistdetails") //a function in your api to get all the list
public void getTaskDetail(#Query("task_uuid") String task_uuid,Callback<Task> callback); //this is an example of response POJO - make sure your variable name is the same with your json tagging
}
Create another interface class to hold all your BASE ADDRESS of your api
public interface Constants{
public String URL = "www.yoururl.com"
}
In your Login activity create a method to handle the retrofit
private void myLogin(String username,String password){
RestAdapter restAdapter = new RestAdapter.Builder()
.setEndpoint(Constants.URL) //call your base url
.build();
MyApi mylogin = restAdapter.create(MyApi.class); //this is how retrofit create your api
mylogin.login(username,password,new Callback<String>() {
#Override
public void success(String s, Response response) {
//process your response if login successfull you can call Intent and launch your main activity
}
#Override
public void failure(RetrofitError retrofitError) {
retrofitError.printStackTrace(); //to see if you have errors
}
});
}
In your MainActivityList
private void myList(String user_uuid){
RestAdapter restAdapter = new RestAdapter.Builder()
.setEndpoint(Constants.URL) //call your base url
.build();
MyApi mytask = restAdapter.create(MyApi.class); //this is how retrofit create your api
mytask.getTaskDetail(user_uuid,new Callback<Task>>() {
#Override
public void success(ArrayList<Task> list, Response response) {
//process your response if successful load the list in your listview adapter
}
#Override
public void failure(RetrofitError retrofitError) {
retrofitError.printStackTrace(); //to see if you have errors
}
});
}
In your Detailed List
private void myDetailed(String task_uuid){
RestAdapter restAdapter = new RestAdapter.Builder()
.setEndpoint(Constants.URL) //call your base url
.build();
MyApi mytask = restAdapter.create(MyApi.class); //this is how retrofit create your api
mytask.getTaskList(task_uuid,new Callback<Task>() {
#Override
public void success(Task task, Response response) {
//process your response if successful do what you want in your task
}
#Override
public void failure(RetrofitError retrofitError) {
retrofitError.printStackTrace(); //to see if you have errors
}
});
}
Hope this would help you though its really the simplest way to use retrofit.
Take a look at this , excellent blog on using Retrofit in conjunction with Otto, both libraries are from Square.
http://www.mdswanson.com/blog/2014/04/07/durable-android-rest-clients.html
The basic idea is that you will hold a reference to a "repository" object in your Application class. This object will have methods that "subscribe" to rest api event requests. When one is received it will make the proper Retrofit call, and then "post" the response, which can then be "subscribed" to by another component (such as the activity that made the request).
Once you have this all setup properly, accessing data via your rest api becomes very easy. For example, making are request for data would look something like this :
mBus.post(new GetMicropostsRequest(mUserId));
and consuming the data would look something like this:
#Subscribe
public void onGetUserProfileResponse(GetUserProfileResponse event) {
mView.setUserIcon("http://www.gravatar.com/avatar/" + event.getGravatar_id());
mView.setUserName(event.getName());
}
It takes a little bit of upfront effort, but in the end it becomes "trivial" to access anything you need from our backend via Rest.
You may try saving references to your api inside your application class. Then you can get it's instance from any activity or fragment and get api from there. That sounds a little weird, but it may be a simple DI alternative. And if you will only store references in your app class, it won't be a kind of god object
UPD: http://square.github.io/retrofit/ - here is some documentation, it might be useful
Using RetroFit is very easy.
Add dependecy in build.gradle.
compile 'com.squareup.retrofit:retrofit:1.9.0'
compile 'com.squareup.okhttp:okhttp:2.4.0'
Make an Interface for all http methods.
Copy your json output and create pojo class to recieve json of your
response, you can make pojo from JsonSchema2pojo site .
make an adapter and call your method
for complete demo try this tutorial Retrofit Android example
Checkout this app that demonstrates Retrofit integration to Google Tasks API.
https://github.com/sschendel/SyncManagerAndroid-DemoGoogleTasks
There are examples of Retrofit api (TaskApi) used within Activity AsyncTask in MainActivity, as well as examples of use within Sync Adapter in background service.
The strategy from the article posted in #nPn's answer is probably a more elegant solution, but you can at least look at another working example.
Firstly, putting everything in MainActivity would be bad practice and you would end up with a God object.
The documentation on the Retrofit site is fantastic, so I'm going to read your question on how to structure the project. I wrote a very small app for demonstration purposes. It loads cats from the cat API and should be fairly simple to follow what is happening.
It has an example of using JSON or XML for the parsing of data from the service. You can find it at https://github.com/codepath/android_guides/wiki/Consuming-APIs-with-Retrofit
Hopefully you can extrapolate why I have structured it the way I have. I'm happy to answer any questions you have in the comments and update the answer.
I find these tutorials AndroidHive , CodePath helpful
I will briefly describe what I have learned.
Step 1 : Add these three dependencies to build.gradle and Add Internet permission to Manifest
compile 'com.google.code.gson:gson:2.6.2' // for string to class conversion. Not Compulsory
compile 'com.squareup.retrofit2:retrofit:2.1.0'// compulsory
compile 'com.squareup.retrofit2:converter-gson:2.1.0' //for retrofit conversion
Add them in Manifest
<uses-permission android:name="android.permission.INTERNET" />
Step 2
Creae ApiClient and ApiInterface.
public class ApiClient {
public static final String BASE_URL = "http://yourwebsite/services/";
private static Retrofit retrofit = null;
public static Retrofit getClient() {
if (retrofit==null) {
retrofit = new Retrofit.Builder()
.baseUrl(BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.build();
}
return retrofit;
}
}
where ApiInterface.class
public interface ApiInterface {
// getting same data in three different ways.
#GET("GetCompanyDetailByID")
Call<CompanyResponse> getDetailOfComapanies(#Query("CompanyID") int companyID);
#GET("GetCompanyDetailByID")
Call<ResponseBody> getRawDetailOfCompanies(#Query("CompanyID") int companyID);
#GET("{pathToAdd}")
Call<CompanyResponse> getDetailOfComapaniesWithPath(#Path("pathToAdd") String pathToAppend, #Query("CompanyID") int companyID);
}
And call this service like
ApiInterface apiService =
ApiClient.getClient().create(ApiInterface.class);
Call<CompanyResponse> companyResponseCall = apiService.getDetailOfComapanies(2);
//Call<CompanyResponse> companyResponseCall = apiService.getDetailOfComapaniesWithPath("GetCompanyDetailByID",2);
companyResponseCall.enqueue(new Callback<CompanyResponse>() {
#Override
public void onResponse(Call<CompanyResponse> call, Response<CompanyResponse> response) {
CompanyResponse comapnyResponse = response.body();
Boolean status = comapnyResponse.getStatus();
}
#Override
public void onFailure(Call<CompanyResponse> call, Throwable t) {
}
});
For Getting Raw Json String
Call<ResponseBody> call = apiService.getRawDetailOfCompanies(2);
call.enqueue(new Callback<ResponseBody>() {
#Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
String jsonStr = response.body().string();
if(!jsonStr.isEmpty()){
Gson gson = new Gson();
JSONObject jObject = new JSONObject(jsonStr).getJSONObject("data");
//1st Method
Data dataKiType = gson.fromJson(jObject.toString(), Data.class);
dataKiType.getCompanyDetail();
//2nd method for creaing class or List at runTime
Type listType = new TypeToken<Data>(){}.getType();
Data yourClassList = new Gson().fromJson(jObject.toString(), listType);
yourClassList.getCompanyDetail();
} e.printStackTrace();
}
}
#Override
public void onFailure(Call<ResponseBody> call, Throwable t) {
}
});
You can create your business object using http://www.jsonschema2pojo.org/ by simply pasting json. and selecting source type to JSON and Annotation Style to GSon
Found a small, but complete and concise example at
https://github.com/square/retrofit/tree/master/samples
Beginners find it little intimidating to learn retrofit. I have prepared a tutorial which will simplify the learning curve. See Retrofit android tutorial for more information.
Developing your own type-safe HTTP library to interface with a REST API can be a real pain: you have to handle many aspects, such as making connections, caching, retrying failed requests, threading, response parsing, error handling, and more. Retrofit, on the other hand, is a well-planned, documented and tested library that will save you a lot of precious time and headaches.
compile 'com.google.code.gson:gson:2.6.2'
compile 'com.squareup.retrofit2:retrofit:2.1.0'// compulsory
compile 'com.squareup.retrofit2:converter-gson:2.1.0' //for retrofit conversion
First, add this lines to gradle file
compile 'com.squareup.retrofit2:retrofit:2.1.0'
compile 'com.squareup.retrofit2:converter-gson:2.1.0'
compile 'com.google.code.gson:gson:2.7'
compile 'com.squareup:otto:1.3.8'
compile 'com.squareup.okhttp3:logging-interceptor:3.4.1'
Then Create Objects in OnCreate of Activity
HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
OkHttpClient client= new OkHttpClient
.Builder()
.connectTimeout(30, TimeUnit.SECONDS)
.readTimeout(30, TimeUnit.SECONDS)
.addInterceptor(interceptor).build();
Gson gson=new GsonBuilder()
.setDateFormat("yyyy-MM-dd'T'HH:mm:ssZ")
.create();
Retrofit retrofit= new Retrofit.Builder()
.baseUrl("url")
.client(client)
.addConverterFactory(GsonConverterFactory.create(gson))
.build();
Create an iterface
public interface summaryListAPI {
//post
#FormUrlEncoded
#POST("index.php")
Call<summaryList> post(
#Field("status") String status,
#Field("sox") String sox
);
//get
#GET("yesbdeChatHistoryList/{userId}/")
Call<List<ChatTabTwoResp>> getFriends(
#Path("userId") int userId
);
}
Create classes
public class summaryList {
#SerializedName("bookingSummary") #Expose private List<summaryListData> status = new ArrayList<summaryListData>();
}
public class summaryListData {
#SerializedName("date") #Expose private String date;
}
Add this Method to your activity
public void apiSummaryListMain(final Retrofit retrofit) {
retrofit.create(summaryListAPI.class).post("8547861657","100").enqueue(new Callback<summaryList>() {
#Override
public void onResponse(Call<summaryList> call, Response<summaryList> response) {
if (response.isSuccessful()) {
progressBar.setVisibility(View.INVISIBLE);
List<summaryListData> summary_List= response.body().getStatus();
}else{
}
}
#Override
public void onFailure(Call<summaryList> call, Throwable t) {
}
});
}
Its Working
package com.keshav.gmailretrofitexampleworking.network;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;
public class ApiClient {
public static final String BASE_URL = "http://api.androidhive.info/json/";
private static Retrofit retrofit = null;
public static Retrofit getClient() {
if (retrofit == null) {
retrofit = new Retrofit.Builder()
.baseUrl(BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.build();
}
return retrofit;
}
}
==============================================
package com.keshav.gmailretrofitexampleworking.network;
import com.keshav.gmailretrofitexampleworking.models.Message;
import java.util.List;
import retrofit2.Call;
import retrofit2.http.GET;
public interface ApiInterface {
#GET("inbox.json")
Call<List<Message>> getInbox();
}
compile 'com.google.code.gson:gson:2.6.2'
compile 'com.squareup.retrofit2:retrofit:2.0.2'
compile 'com.squareup.retrofit2:converter-gson:2.0.2'
=====================================================
Call Retrofit 2 APi inside onCreate
private void getInbox() {
swipeRefreshLayout.setRefreshing(true);
ApiInterface apiService =
ApiClient.getClient().create(ApiInterface.class);
Call<List<Message>> call = apiService.getInbox();
call.enqueue(new Callback<List<Message>>() {
#Override
public void onResponse(Call<List<Message>> call, Response<List<Message>> response) {
// clear the inbox
messages.clear();
// add all the messages
// messages.addAll(response.body());
// TODO - avoid looping
// the loop was performed to add colors to each message
Log.e("keshav","response" +response.body());
for (Message message : response.body()) {
// generate a random color
// TODO keshav Generate Random Color Here
message.setColor(getRandomMaterialColor("400"));
messages.add(message);
}
mAdapter.notifyDataSetChanged();
swipeRefreshLayout.setRefreshing(false);
}
#Override
public void onFailure(Call<List<Message>> call, Throwable t) {
Toast.makeText(getApplicationContext(), "Unable to fetch json: " + t.getMessage(), Toast.LENGTH_LONG).show();
swipeRefreshLayout.setRefreshing(false);
}
});
}
Source Code
https://drive.google.com/open?id=0BzBKpZ4nzNzUVFRnVVkzc0JabUU
https://drive.google.com/open?id=0BzBKpZ4nzNzUc2FBdW00WkRfWW8
I just braked this problem in a very easy way you just need install a plugin and follow some steps to implement retrofit in any of your App.:
Already posted answer : Retrofit in android?
Add (QAssist - Android Studio Plugin) Android plugin in your Android studio. ( https://github.com/sakkeerhussain/QAssist ).
Hope this will help you.
Simple retrofit + okhttp integration using RxJava
public WebService apiService(Context context) {
String mBaseUrl = context.getString(BuildConfig.DEBUG ? R.string.local_url : R.string.live_url);
int cacheSize = 5 * 1024 * 1024; // 5 MB
Cache cache = new Cache(context.getCacheDir(), cacheSize);
HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor();
loggingInterceptor.setLevel(BuildConfig.DEBUG ? HttpLoggingInterceptor.Level.BODY : HttpLoggingInterceptor.Level.NONE);
OkHttpClient okHttpClient = new OkHttpClient.Builder()
.readTimeout(120, TimeUnit.SECONDS)
.writeTimeout(120, TimeUnit.SECONDS)
.connectTimeout(120, TimeUnit.SECONDS)
.addInterceptor(loggingInterceptor)
//.addNetworkInterceptor(networkInterceptor)
.cache(cache)
.build();
return new Retrofit.Builder().baseUrl(mBaseUrl)
.client(okHttpClient)
.addConverterFactory(GsonConverterFactory.create())
.addCallAdapterFactory(RxJava2CallAdapterFactory.create())
.build().create(WebService.class);
}
public interface APIService {
#POST(Constant.updateProfile)
#FormUrlEncoded
Call<ResponseBody> updateProfile(
#Field("user_id") String user_id,
#Field("first_name") String first_name,
#Field("last_name") String last_name
);
}
public class RetrofitClient {
private static Retrofit retrofit = null;
public static Retrofit getClient(String baseUrl) {
if (retrofit == null) {
retrofit = new Retrofit.Builder()
.baseUrl(baseUrl)
.addConverterFactory(GsonConverterFactory.create())
.build();
}
return retrofit;
}
}
public class Body {
// Check Status if Status True or False
String status;
String message;
String checksum;
}
public interface OnBodyResponseListner {
public void onSucces(Body response);
public void onFailure(Body response);
public void onBlankBody(Call<ResponseBody> call);
}
public static void setOnWebServiceCallListner(final Call<ResponseBody> t, final OnBodyResponseListner onBodyResponseListner) {
t.enqueue(new Callback<ResponseBody>() {
#Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
try {
call.cancel();
Gson gson = new GsonBuilder().serializeNulls().create();
String json = response.body().string();
Log.d(TAG, json + " ~ Response ~ " + json);
Body body = gson.fromJson(json, Body.class);
if (body.getStatus().equalsIgnoreCase("true")) {
onBodyResponseListner.onSucces(body);
} else {
onBodyResponseListner.onFailure(body);
}
} catch (Exception e) {
}
}
#Override
public void onFailure(Call<ResponseBody> call, Throwable t) {
onBodyResponseListner.onBlankBody(call);
Log.d(TAG, "~ Response Message Blank ~ " + t.getMessage() + " \n Localize Message ~ " + t.getLocalizedMessage() + " \n" + t.getStackTrace().toString());
}
});
}
APIService mService = RetrofitClient.getClient(Constant.BASE_URL).create(APIService.class);
Oprations.setOnWebServiceCallListner(mService.updateProfile("12",
"first_name",
"last,name"
), new OnBodyResponseListner() {
#Override
public void onSucces(Body response) {
}
#Override
public void onFailure(Body response) {
Toast.makeText(mContext, response.getMessage(), Toast.LENGTH_SHORT).show();
}
#Override
public void onBlankBody(Call<ResponseBody> call) {
}
});
}
First, add the dependency - compile 'com.squareup.retrofit:retrofit:1.7.1'
Create retrofit instance class
public class RetrofitClientInstance {
private Context context;
private static OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
private static Retrofit retrofit
private static Retrofit.Builder builder =
new Retrofit.Builder()
.baseUrl(BuildConfig.SERVER_URL)
.client(getRequestHeader())
.addConverterFactory(GsonConverterFactory.create());
public static HttpLoggingInterceptor setLogger() {
HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
logging.setLevel(HttpLoggingInterceptor.Level.BODY);
return logging;
}
public static <S> S createService(Class<S> serviceClass) {
if (!httpClient.interceptors().isEmpty()) {
httpClient.interceptors().clear();
}
httpClient.authenticator(new AccessTokenAuthenticator());
httpClient.readTimeout(60,TimeUnit.SECONDS);
httpClient.connectTimeout(60,TimeUnit.SECONDS);
httpClient.addInterceptor(setLogger());
httpClient.addInterceptor(new Interceptor() {
#Override
public Response intercept(Chain chain) throws IOException {
Request original = chain.request();
Request.Builder requestBuilder = original.newBuilder()
.header("LocalSystemDate", MyApplication.getInstance().getCurrentDateAndTimeWithTimeZone())
.addHeader("channel_id", AppConst.CHANNEL_ID)
.addHeader("Authorization", "Bearer" + " " + SharedPref.getsAccessToken())
.method(original.method(), original.body());
Request request = requestBuilder.build();
return chain.proceed(request);
}
});
OkHttpClient client = httpClient.build();
Retrofit retrofit = builder.client(client).build();
return retrofit.create(serviceClass);
}
private static OkHttpClient getRequestHeader() {
return new OkHttpClient.Builder()
.readTimeout(60, TimeUnit.SECONDS)
.connectTimeout(60, TimeUnit.SECONDS)
.build();
}
}
Write the interface
public interface GetDataService {
#Headers("Content-Type: application/json")
#POST("login")
Call<LoginResponseModel> loginUser(
#Body LoginBodyModel loginBodyModel
);
}
Call the service
GetDataService service = RetrofitClientInstance.createService(GetDataService.class);
Call<LoginResponseModel> loginModelCall = service.loginUser(loginBodyModel);
loginModelCall.enqueue(new Callback<LoginResponseModel>() {
#Override
public void onResponse(Call<LoginResponseModel> call, Response<LoginResponseModel> response) {
}
#Override
public void onFailure(Call<LoginResponseModel> call, Throwable t) {
}
});
You can do this with hilt
#Module
#InstallIn(SingletonComponent::class)
object RestClientModule {
#Provides
#Singleton
internal fun provideApiService(
#WeatherRetrofit retrofit: Retrofit
): ApiService = retrofit.create(ApiService::class.java)
#Provides
#WeatherRetrofit
#Singleton
internal fun provideHiCityRetrofit(
okHttpClient: OkHttpClient,
moshi: Moshi
): Retrofit = Retrofit.Builder()
.baseUrl(EndPoint.STAGE_BASE_URL)
.client(okHttpClient)
.addConverterFactory(ScalarsConverterFactory.create())
.addConverterFactory(MoshiConverterFactory.create(moshi))
.build()
}
You can checkout this Github Link with source-code avaible for login and signup API in android. https://github.com/probelalkhan/kotlin-retrofit-tutorial/commits/master
Or you can check this tutorial for learning purpose.
https://youtu.be/TyJEDhauUeQ
Or for more other details checkout this
https://gist.github.com/codinginflow/d7a02bd69eebf566b4650c41bc362be7

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