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Crash appears on a member variable that is null despite Gson converter that never returns null: impossible case

In my Activity, I have a Training object member initialized during onCreate(). All the members of this object are set.
private Training mTraining; is a class member
public class Training extends BaseModel {
...
#SerializedName("state")
public TrainingState state;
....
public TrainingPreview() {
}
This object is got from server (JSON), and I had a converter on this state to ensure this enum can't be null (I use GSON engine):
public class TrainingStateConverter extends EnumConverter<TrainingState> {
public static final Type TYPE = new TypeToken<TrainingState>() {}.getType();
#Override
protected TrainingState deserialize(String value) {
return TrainingState.fromString(value);
}
#Override
protected TrainingState getUnknownValue() {
return TrainingState.UNKNOWN;
}
}
During the setup, I've created the exercise list with the listener to show a specific exercise:
private void refreshExercisesList() {
final Runnable showTrainingParts = new Runnable() {
public void run() {
int nbItems = mCardExercises.setExercises(mTraining.training, mTraining.state,
new FlatCardTrainingProfilePartExercisesView.OnClickExerciseListener() {
#Override
public void showPart(String trainingPartId, int index) {
onClickOnExercisesList(trainingPartId, index);
}
});
}
};
}
...
}
My onClickOnExercisesList() method:
private void onClickOnExercisesList(String trainingPartId, int index) {
...
switch (mTraining.state) {
...
This Activity code works perfectly since couple of months, but yesterday there was a NullPointerException on switch (mTraining.state) :
int com.xxx.model.training.TrainingState.ordinal()' on a null object reference
com.xxx.ui.training.TrainingActivity.onClickOnExercisesList
How is possible guys?
Thank you very much for your help!

This would occur if state did not appear in the JSON.
The TypeConverter is only used if there is a value in the JSON to convert. If the value isn't present, then there's nothing to convert, so the value is whatever the default is, which is null, because you didn't set it:
#SerializedName("state")
public TrainingState state;
To fix the issue, initialize the variable to a default value:
#SerializedName("state")
public TrainingState state = TrainingState.UNKNOWN;

No setter/field for found Android Firebase

I used FirebaseRecyclerAdapter to get all the childs of "Pro" using a Model class named " Spacecraft" and now I want to retrieve all the candidates into a child of Pro like "1"
I created a public static "candidat" into "Spacecraft" and I used the setters and getters but still the same error
This is my database:
this is the Model Class
public class Spacecraft{
private String name;
private String desc;
private String last;
private candidat candidat;
public Spacecraft.candidat getCandidat() {
return candidat;
}
public void setCandidat(Spacecraft.candidat candidat) {
this.candidat = candidat;
}
public Spacecraft() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDesc() {
return desc;
}
public void setDesc(String desc) {
this.desc = desc;
}
public String getLast() {
return last;
}
public void setLast(String last) {
this.last = last;
}
public static class candidat{
private String info;
private String namecandid;
public candidat(){}
public String getInfo() {
return info;
}
public void setInfo(String info) {
this.info = info;
}
public String getNamecandid() {
return namecandid;
}
public void setNamecandid(String namecandid) {
this.namecandid = namecandid;
}
}
}
This is my code for FirebaseRecyclerAdapter
#Override
protected void onStart() {
super.onStart();
FirebaseRecyclerAdapter<Spacecraft, candidatviewholder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Spacecraft, candidatviewholder>(
Spacecraft.class,
R.layout.candidat,
candidatviewholder.class,
query){
#Override
protected void populateViewHolder(candidatviewholder viewHolder, Spacecraft model, int position) {
viewHolder.setName1(model.getCandidat().getNamecandid());
viewHolder.setInfo1(model.getCandidat().getInfo());
}
};
rv.setAdapter(firebaseRecyclerAdapter);
}
The error:
No setter/field for key1 found on class com.example.ilyas.evotingapplication.Spacecraft$candidat

I had this error but the above solutions didn't fix it. Hopefully, this alternate solution will help others. If you have that error occur for almost every variable, chances are that you have Proguard enabled and it is removing the un-used getter and setter methods. To fix this, add a line similar to this to your proguard-rules.pro file:
-keep class com.example.yourapp.ObjectClass
where ObjectClass is the name of your java object class that is stored to Firebase.

I think it's just that your data models on Firebase and in Java differ.
In your java class, the Spacecraft class has a candidat field of type Candidat. But, in the database, the candidat field is really a nested object (map), containing one key Key1, which value is a Candidat structure.
So, depending on what did you want to achieve:
if you wanted each spacecraft to have exactly one candidat: save the database object properly, so {info: "info 1", namecandid: "name 1"} is saved directly under candidat field, not one level deeper, so the field has type Candidat in the code.
if you wanted each spacecraft to have a few candidats: instead of private Candidat candidat field, it should be typed Map<String, Candidat>, because that's the type it has in your database screenshot.

Work for me:
-keepclassmembers class com.myPackageName.MyClassName { *; }

Failed to handle RealmList<RealmList<RealmInt>> in Realm.io

My JSON data looks like this from server api
{
//...
PredecessorIds:[[1,2][3,4][5]]
//...
}
I can successfully handle the arrays of Integer or String by RealmList<RealmInt> but this time I failed with an error, because RealmList> is not supported saying, "Type parameter 'io.realm.realmList' is not within its bounds...."
For RealmInt see this link.
I tried to solve it using RealmList<RealmLista> where RealmLista extends from RealmObject and has a RealmList like this
public class RealmLista extends RealmObject {
public RealmList<RealmInt> value;
public RealmLista() {
}
public RealmLista(RealmList<RealmInt> val) {
this.value = val;
}
}
and then created a RealmListaTypeAdapter and added it to Gson but when deserializing Gson expects an Object (RealmLista) but is found array, as the data shown above from server is obvious.
//RealmListAdapter for Gson
#Override
public RealmLista read(JsonReader in) throws IOException {
RealmLista lista = new RealmLista();
Gson gson = new Gson();
//how to read that [[1],[3,4]] int into RealmLista
in.beginArray();
while (in.hasNext()) {
lista.value.add(new RealmInt(in.nextInt()));
}
in.endArray();
return lista;
}
Is there any way to store a simple List<List<Integer>> by converting to RealmObject of any type while saving, List<List<Integer>> is easily converted by Gson. :-/

Realm doesn't support lists of lists currently. See https://github.com/realm/realm-java/issues/2549.
So #EpicPandaForce's idea about creating a RealmObject that holds that inner list is probably the best work-around.
It could look something like this:
public class Top extends RealmObject {
private RealmList<ChildList> list;
}
public class ChildList extends RealmObject {
private RealmList<RealmInt> list;
}
public class RealmInt extends RealmObject {
private int i;
}
The correct link for the gist should be: https://gist.github.com/cmelchior/1a97377df0c49cd4fca9

RoboGuice with Standard Android JUnit test cases

I want to use RoboGuice in a standard Android JUnit instrumentation test case and override one piece of my app's actual wiring with a mock for testing. I can't find anything online that explains how to do this as all of my search results go to Robolectric with RoboGuoice. I am not using Robolectric nor can I use it in my app for various reasons. Has anyone wired an app with RoboGuice and injected mocks for standard Android Intrumentation test cases?

I'm using the Roboguice 3 and I solved this problem with the following setup and teardown methods within the standard ActivityInstrumentationTestCase2.
Obviously you would need to replace new TestModule() in the snippet below with your own test module class.
#Override
protected void setUp() throws Exception {
super.setUp();
Application app = (Application)getInstrumentation().getTargetContext()
.getApplicationContext();
RoboGuice.getOrCreateBaseApplicationInjector(app, RoboGuice.DEFAULT_STAGE,
Modules.override(RoboGuice.newDefaultRoboModule(app))
.with(new TestModule()));
getActivity();
}
#Override
protected void tearDown() throws Exception {
RoboGuice.Util.reset();
super.tearDown();
}

I've managed to get it work in a simple usage way, you just bind dependencies inside rule using builder and may forget about them later, it will do everything by itself. You may think it's over engineered, but it's realy good for reusing if tyou have a many test classes with robo guice dependencies inside.
Usage in test classes looks like:
#Rule
public InjectWithMocksRule injectWithMocksRule = new InjectWithMocksRule(
this,
() -> new InjectRule
.BindingBuilder()
.add(MyClass.class, mockedClassImpl)
.add(SomeInterface.class, mockedInterfaceImpl));
I wrote helper class TestBindingModule:
public class TestBindingModule extends AbstractModule {
private HashMap<Class<?>, Object> bindings = new HashMap<Class<?>, Object>();
#Override
#SuppressWarnings("unchecked")
protected void configure() {
Set<Entry<Class<?>, Object>> entries = bindings.entrySet();
for (Entry<Class<?>, Object> entry : entries) {
bind((Class<Object>) entry.getKey()).toInstance(entry.getValue());
}
}
public void addBinding(Class<?> type, Object object) {
bindings.put(type, object);
}
public void addBindings(HashMap<Class<?>, Object> bindings) {
this.bindings.putAll(bindings);
}
public static void setUp(Object testObject, TestBindingModule module) {
Module roboGuiceModule = RoboGuice.newDefaultRoboModule(RuntimeEnvironment.application);
Module testModule = Modules.override(roboGuiceModule).with(module);
RoboGuice.getOrCreateBaseApplicationInjector(RuntimeEnvironment.application, RoboGuice.DEFAULT_STAGE, testModule);
RoboInjector injector = RoboGuice.getInjector(RuntimeEnvironment.application);
injector.injectMembers(testObject);
}
public static void tearDown() {
Application app = RuntimeEnvironment.application;
DefaultRoboModule defaultModule = RoboGuice.newDefaultRoboModule(app);
RoboGuice.getOrCreateBaseApplicationInjector(app, RoboGuice.DEFAULT_STAGE, defaultModule);
}
}
Than I use custom Rule to make it work easy:
public class InjectRule implements TestRule {
public interface BindingBuilderFactory {
BindingBuilder create();
}
public static class BindingBuilder {
private HashMap<Class<?>, Object> bindings = new HashMap<>();
public BindingBuilder add(Class<?> dependencyClass, Object implementation) {
bindings.put(dependencyClass, implementation);
return this;
}
HashMap<Class<?>, Object> buildBindings() {
return this.bindings;
}
}
private Object target;
private BindingBuilderFactory bindingBuilderFactory;
public InjectRule(Object target, BindingBuilderFactory bindingBuilderFactory) {
this.target = target;
this.bindingBuilderFactory = bindingBuilderFactory;
}
private void overrideTestInjections(Object target) {
TestBindingModule module = new TestBindingModule();
module.addBindings(this.bindingBuilderFactory.create().buildBindings());
TestBindingModule.setUp(target, module);
}
#Override
public Statement apply(Statement base, Description description) {
return new StatementDecorator(base);
}
private class StatementDecorator extends Statement {
private Statement baseStatement;
StatementDecorator(Statement b) {
baseStatement = b;
}
#Override
public void evaluate() throws Throwable {
before();
try {
baseStatement.evaluate();
} catch (Error e) {
throw e;
} finally {
after();
}
}
void after() {
TestBindingModule.tearDown();
}
void before() {
overrideTestInjections(target);
}
}
}
Also you may want to init mocks with #Mock annotation inside of your test classes, so you need another custom rule:
public class MockitoInitializerRule implements TestRule {
private Object target;
public MockitoInitializerRule(Object target) {
this.target = target;
}
#Override
public Statement apply(Statement base, Description description) {
return new MockitoInitializationStatement(base, target);
}
private class MockitoInitializationStatement extends Statement {
private final Statement base;
private Object test;
MockitoInitializationStatement(Statement base, Object test) {
this.base = base;
this.test = test;
}
#Override
public void evaluate() throws Throwable {
MockitoAnnotations.initMocks(test);
base.evaluate();
}
}
}
And, finaly, you want to combine them to mock mocks first and then set them as dependencies:
public class InjectWithMocksRule implements TestRule {
private final RuleChain delegate;
public InjectWithMocksRule(Object target, InjectRule.BindingBuilderFactory bindingBuilderFactory) {
delegate = RuleChain
.outerRule(new MockitoInitializerRule(target))
.around(new InjectRule(target, bindingBuilderFactory));
}
#Override
public Statement apply(Statement base, Description description) {
return delegate.apply(base, description);
}
}

Not Serializable Exception on custom class - Android

So I'm trying to pass an instance of a class I create by intent to a new activity.
public class Room implements Serializable{
/**
*
*/
private static final long serialVersionUID = 6857044522819206055L;
int roomID;
String roomName;
ArrayList<MarkerHolder> markerHolders = new ArrayList<MarkerHolder>();
public int getRoomID() {
return roomID;
}
public void setRoomID(int roomID) {
this.roomID = roomID;
}
public String getRoomName() {
return roomName;
}
public void setRoomName(String roomName) {
this.roomName = roomName;
}
public ArrayList<MarkerHolder> getMarkerHolders() {
return markerHolders;
}
public void setMarkerHolders(ArrayList<MarkerHolder> markerHolders) {
this.markerHolders = markerHolders;
}
}
public class MarkerHolder implements Serializable{
/**
*
*/
private static final long serialVersionUID = -7334724625702415322L;
String marker;
String markerTag;
public String getMarker() {
return marker;
}
public void setMarker(String marker) {
this.marker = marker;
}
public String getMarkerTag() {
return markerTag;
}
public void setMarkerTag(String markerTag) {
this.markerTag = markerTag;
}
}
And I try to pass that class by
Intent svc = new Intent(this, RoomUploader.class);
svc.putExtra("room", room);
try{
startService(svc);
}catch (Exception e){
e.printStackTrace();
}
and I keep getting a Not Serializable Exception which I can't figure out. Both classes implement serializable and have serial Ids. The member variables are just strings, ints, and an array of another class that is also serializable that contains only strings. As far as I know all these things should be serializable, what else could cause this error? Thanks in advance.

Are those classes inner classes of your activity or another class? If so, they have a reference to their outer class (which may or may not be serializable), and you can solve this by making those classes static.
Example:
public static class Room implements Serializable
{
//your implementation
}
public static class MarkerHolder implements Serializable
{
//your implementation
}

Try changing ArrayList to a native array of MarkerHolder:
MarkerHolder[] markerHolders;
Update: My bad. I've always used native array for serialization so not aware ArrayList is indeed serialzable.
Your code looks right. What was the exact error message printed in the logcat (i.e. which class threw the serialization exception)?
Another solution (more work) is to make your objects implement the Parcable interface.

Try to use getApplicationContext() or context instaed of this.