I am getting reports of crashes in the Android Pre-Launch report. Everything works fine on my emulator and three physical test devices that I have. The error being reported is the following
Fatal Exception: java.lang.RuntimeException
An error occurred while executing doInBackground()
android.os.AsyncTask$3.done (AsyncTask.java:353)
java.util.concurrent.FutureTask.finishCompletion (FutureTask.java:383)
java.util.concurrent.FutureTask.setException (FutureTask.java:252)
java.util.concurrent.FutureTask.run (FutureTask.java:271)
android.os.AsyncTask$SerialExecutor$1.run (AsyncTask.java:245)
java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1162)
java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:636)
java.lang.Thread.run (Thread.java:764)
Caused by java.lang.IllegalStateException
Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2 path $
com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read (CollectionTypeAdapterFactory.java)
retrofit2.converter.gson.GsonResponseBodyConverter.convert (GsonResponseBodyConverter.java:1)
retrofit2.OkHttpCall.a (OkHttpCall.java:59)
retrofit2.OkHttpCall.execute (OkHttpCall.java:73)
retrofit2.DefaultCallAdapterFactory$ExecutorCallbackCall.execute (DefaultCallAdapterFactory.java:2)
com.cn.managers.CNServiceManager.fetchChapters (CNServiceManager.java:2)
com.cn.tasks.FetchChaptersTask.doInBackground (FetchChaptersTask.java:2)
com.cn.tasks.FetchChaptersTask.doInBackground (FetchChaptersTask.java:2)
The doInBackground method in FetchChaptersTask class is as follows
@Override
protected ArrayList<Chapter> doInBackground(Void... voids) {
return CNServiceManager.fetchChapters(subjectId, purpose);
}
In CNServiceManager the method fetchChapters (subjectId, purpose) is defined. This method is basically getting a list of chapters from the API using Retrofit2 and GSON Converter. The API call is given as follows. The CNServiceManager class is given below:
public class CNServiceManager {
public static final String PREF_AUTHENTICATION_TOKEN = "CNServiceManager_authentication_token";
public static final String PREF_SESSION_ID = "CNServiceManager_session_id";
private interface CNService {
@GET("v2/chapters/{subjectId}/{purpose}")
Call<ArrayList<Chapter>> fetchChapters(@Header("Authentication-Token") String authentication,
@Path("subjectId") long subjectId,
@Path("purpose") String purpose);
}
/**
* Authorization token
*/
private static String mAuthorizationToken;
/**
* The main interface to server
*/
private static CNService mCNService;
/**
* Initialize
*
* @param context
*/
public static void init(Context context) {
OkHttpClient httpClient = new OkHttpClient.Builder()
.build();
Retrofit retrofit = new Retrofit.Builder()
.baseUrl("http://192.168.0.105:8000/api/")
.addConverterFactory(GsonConverterFactory.create())
.client(httpClient)
.build();
long applicationId = 9;
String applicationSecret = "AppSecret";
mAuthorizationToken = String.format(Locale.ENGLISH, "%d/%s", applicationId, applicationSecret);
mCNService = retrofit.create(CNService.class);
}
/**
* Returns authorization code
*
* @return
*/
private static String getAuthorizationToken() {
return mAuthorizationToken;
}
/**
* Returns authentication code
*
* @return
*/
private static String getAuthenticationToken() {
return PreferencesManager.getString(PREF_AUTHENTICATION_TOKEN, null);
}
/**
* Returns chapters
*
* @param subjectId
* @param purpose
* @return
*/
public static ArrayList<Chapter> fetchChapters(long subjectId, String purpose) {
try {
Call<ArrayList<Chapter>> call = mCNService.fetchChapters(getAuthenticationToken(), subjectId, purpose);
Response<ArrayList<Chapter>> response = call.execute();
return response.body();
}
catch (IOException e) {
e.printStackTrace();
}
return null;
}
}
Finally, Here's how the Chapter model is coded.
public class Chapter {
/**
* Id of the chapter
*/
private long id;
/**
* Name of the chapter
*/
private String name;
/**
* Chapter
*
* @param id
* @param name
*/
public Chapter(long id, String name) {
this.id = id;
this.name = name;
}
/**
* Chapter
*/
public Chapter() {
this(0, null);
}
/**
* Returns the id of the chapter
*
* @return
*/
public long getId() {
return id;
}
/**
* Sets the id of the chapter
*
* @param id
*/
public void setId(long id) {
this.id = id;
}
/**
* Returns the name of the chapter
*
* @return
*/
public String getName() {
return name;
}
/**
* Sets the name of the chapter
*
* @param name
*/
public void setName(String name) {
this.name = name;
}
}
As I mentioned in the start, I am getting the crash reports in Google Play Pre-Launch Reports and in some live users. But on my devices and emulator, it is not crashing.
Please don't use AsyncTask for Retrofit. Instead, you can you use Reterofit callback as following.
public static void init(Context context) {
OkHttpClient httpClient = new OkHttpClient.Builder()
.build();
Retrofit retrofit = new Retrofit.Builder()
.baseUrl("http://192.168.0.105:8000/api/")
.addConverterFactory(GsonConverterFactory.create())
.client(httpClient)
.build();
long applicationId = 9;
String applicationSecret = "AppSecret";
mAuthorizationToken = String.format(Locale.ENGLISH, "%d/%s", applicationId, applicationSecret);
mCNService = retrofit.create(CNService.class);
// additional code instead of AsyncTask
Call<List<Chapter>> call = mCNService.fetchChapters();
call.enqueue(new Callback<List<Chapter>>() {
@Override
public void onResponse(Call<List<Chapter>> call, Response<List<Chapter>> response) {
progressDoalog.dismiss();
generateDataList(response.body());
}
@Override
public void onFailure(Call<List<Chapter>> call, Throwable t) {
progressDoalog.dismiss();
Toast.makeText(MainActivity.this, "Something went wrong...Please try later!", Toast.LENGTH_SHORT).show();
}
});
}
I hope this will solve your problem