When passing 2 identical Parcable Classes, 1 is null

When passing 2 identical Parcable Classes, 1 is null - android

i have a weird issue.
I'm trying to pass 2 parcable classesfrom one activity to another.
I define both of them the exact same way, but of them is null.
The parcable class :
class Friends implements Parcelable {
private ArrayList<Integer> ids = new ArrayList<Integer>();
private ArrayList<String> names = new ArrayList<String>();
private ArrayList<Bitmap> images = new ArrayList<Bitmap>();
public void addId(Integer id)
{
ids.add(id);
}
public void addName(String name){
names.add(name);
}
public void addImage(Bitmap img){
images.add(img);
}
public ArrayList<Integer> getIds() {
return ids;
}
public ArrayList<String> getNames() {
return names;
}
public ArrayList<Bitmap> getImages() {
return images;
}
#Override
public int describeContents() {
// TODO Auto-generated method stub
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeList(ids);
dest.writeList(names);
dest.writeList(images);
}
public static final Parcelable.Creator<Friends> CREATOR = new Parcelable.Creator<Friends>() {
public Friends createFromParcel(Parcel in) {
return new Friends(in);
}
public Friends[] newArray(int size) {
return new Friends[size];
}
};
public Friends(Parcel in){
in.readList(ids, null);
in.readList(names, null);
in.readList(images, null);
}
public Friends(Integer id, String name, Bitmap img) {
ids.add(id);
names.add(name);
images.add(img);
}
public Friends(){
}
The Sending part :
for(Integer position : selectedIds)
{
String name = a.getItem(position).getFriendName();
int id = a.getItem(position).getFriendId();
Bitmap img = a.getItem(position).getFriendImage();
Log.e("ID",String.valueOf(id));
selectedFriends.addId(new Integer(id));
selectedFriends.addName(name);
selectedFriends.addImage(img);
}
for(int position=0;position<list.getCount(); position++)
{
String name = a.getItem(position).getFriendName();
int id = a.getItem(position).getFriendId();
Bitmap img = a.getItem(position).getFriendImage();
Log.e("All IDs",String.valueOf(id));
allFriends.addId(new Integer(id));
allFriends.addName(name);
allFriends.addImage(img);
}
b.putParcelable("selecet_friends", selectedFriends);
b.putParcelable("all_friends", allFriends);
data.putExtras(b);
Both of the loops are being runned ( i can see the logs), all variables you don't see are being initialized correctly, everything is fine.
The Reciving part :
i define both as null :
private Friends selectedFriends = null;
private Friends allFriends = null;
And handle the onResult like this :
Log.e("Result","yessss");
Friends all_friends = (Friends)data.getParcelableExtra("all_friends");
Friends selected_friends = (Friends)data.getParcelableExtra("selected_friends");
allFriends = all_friends;
selectedFriends = selected_friends;
if(selectedFriends != null){
Log.e("is null","No");
}
if(allFriends != null){
Log.e("is all null","No");
}
Does anyone know how come the selectedFriends is null when allFriends is not?
EDIT:
Just a thought, but maybe it's because i put 2 parcables on a Bundle?
just i just add 2 bundles?

In the sending method you have a typo in this line:
b.putParcelable("selecet_friends", selectedFriends);
try this instead:
b.putParcelable("selected_friends", selectedFriends);
Also, you should use more specific names for the keys. The documentation for putExtras() says:
Add a set of extended data to the intent. The keys must include a
package prefix, for example the app com.android.contacts would use
names like "com.android.contacts.ShowAll

Related

Sorting ArrayList of JSONObjects by a double doesn't work

I'm currently creating an Android app for school but still want to give my best.
I'm pretty new to Android development and coding in general. The app is supposed to be a stock market game. (Btw, I'm German, so there might be some German variables)
So I want to sort my RecyclerView containing shares. It works alphabetically but not by worth.
I can guarantee that the name "worth" of the double in the JSONObject is correct. What am I doing wrong?
public class CompanyAdapter extends RecyclerView.Adapter<CompanyAdapter.viewHolder> implements Filterable {
private CustomFilter filter;
private ArrayList<JSONObject> jObjList;
private final String keyName;
private final String keyWorth;
private final String keyChange;
public final static int SORT_ALPHABETICALLY = 0;
public final static int SORT_ALPHABETICALLY_REVERSE = 1;
public final static int SORT_BY_WORTH = 2;
public final static int SORT_BY_WORTH_REVERSE = 3;
public CompanyAdapter(Context context, ArrayList<JSONObject> jObjList) {
this.jObjList = jObjList;
Context c = context;
keyName = c.getResources().getString(R.string.nameCompany);
keyWorth = c.getResources().getString(R.string.worthCompany);
keyChange = c.getResources().getString(R.string.changeCompany);
sort(SORT_ALPHABETICALLY);
}
//left out some unnecessary code
public void sort (int sorting) {
if (jObjList.size()>1) {
switch (sorting) {
case SORT_ALPHABETICALLY:
sortAlphabetically();
break;
case SORT_ALPHABETICALLY_REVERSE:
sortAlphabeticallyReverse();
break;
case SORT_BY_WORTH:
sortByWorth();
break;
case SORT_BY_WORTH_REVERSE:
sortByWorthReverse();
break;
}
}
}
private void sortAlphabetically () {
Collections.sort(jObjList, new Comparator<JSONObject>() {
#Override
public int compare(JSONObject j1, JSONObject j2) {
try {
return j1.getString(keyName).compareToIgnoreCase(j2.getString(keyName));
} catch (JSONException e) {
return 0;
}
}
});
}
private void sortAlphabeticallyReverse () {
sortAlphabetically();
Collections.reverse(jObjList);
}
private void sortByWorth () {
Collections.sort(jObjList, new Comparator<JSONObject>() {
#Override
public int compare(JSONObject j1, JSONObject j2) {
try {
return Double.compare(j1.getDouble(keyWorth), j2.getDouble(keyWorth));
} catch (JSONException e) {
Log.e("JSONException", e.getMessage());
return 0;
}
}
});
}
private void sortByWorthReverse () {
sortByWorth();
Collections.reverse(jObjList);
}
}

try to replace
return Double.compare(j1.getDouble(keyWorth), j2.getDouble(keyWorth));
with
System.out.print("VALUE1: "+j1.getDouble(keyWorth));
System.out.print("VALUE2: "+j2.getDouble(keyWorth));
return (int)(j1.getDouble(keyWorth)-j2.getDouble(keyWorth));
as well to make sure and debug the value print it.
and after sortByWorth();
add notifyDataSetChanged();

Have you checked the values of the objects you are comparing within the console?
Since you are reading in the values as a string, perhaps they will not be giving the result you expect.
Furthermore, what operation is the compare function performing?

Replace:
return Double.compare(j1.getDouble(keyWorth), j2.getDouble(keyWorth));
In sortByWorth method, to:
return j1.getDouble(keyWorth).compareTo(j2.getDouble(keyWorth))
Try it..

I forgot the notifyDataSetChanged(). Sorry, that's a stupid error.

java.lang.RuntimeException: Parcel android.os.Parcel: Unmarshalling unknown type code

I seem to be getting a strange error in my app (see GitHub), which occurs when I pass objects to different activities that implement Parcelable.
I have checked other questions and answers here on Stack Overflow, but I was unable to find a solution. I've tried the answer here, for example - here it is for reference:
-keepclassmembers class * implements android.os.Parcelable {
static ** CREATOR;
}
I've also made sure that the method calls in writeToParcel are in order. Most other questions on Stack Overflow about this issue don't have answers.
Moreover, the reason I am asking a new question is because I think my problem is caused because of how I have used interfaces in my app (I will expand on this point later on). Other questions on Stack Overflow would not suit my particular scenario.
In the following, I have provided links to the code via GitHub, so that you can explore more of the code if required.
When I click on a button to launch a new activity (passing an object that implements Parcelable), there is a crash:
Process: com.satsuware.flashcards, PID: 4664
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.satsuware.flashcards/com.satsumasoftware.flashcards.ui.FlashCardActivity}: java.lang.RuntimeException: Parcel android.os.Parcel#d2219e4: Unmarshalling unknown type code 6815860 at offset 200
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
...
Caused by: java.lang.RuntimeException: Parcel android.os.Parcel#d2219e4: Unmarshalling unknown type code 6815860 at offset 200
at android.os.Parcel.readValue(Parcel.java:2319)
at android.os.Parcel.readListInternal(Parcel.java:2633)
at android.os.Parcel.readArrayList(Parcel.java:1914)
at android.os.Parcel.readValue(Parcel.java:2264)
at android.os.Parcel.readArrayMapInternal(Parcel.java:2592)
at android.os.BaseBundle.unparcel(BaseBundle.java:221)
at android.os.Bundle.getParcelable(Bundle.java:786)
at android.content.Intent.getParcelableExtra(Intent.java:5377)
at com.satsumasoftware.flashcards.ui.FlashCardActivity.onCreate(FlashCardActivity.java:71)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
...
I call the aforementioned activity like so (also see GitHub):
Intent intent = new Intent(TopicDetailActivity.this, FlashCardActivity.class);
intent.putExtra(FlashCardActivity.EXTRA_TOPIC, mTopic);
intent.putExtra(FlashCardActivity.EXTRA_NUM_CARDS, mSelectedNumCards);
intent.putExtra(FlashCardActivity.EXTRA_CARD_LIST, mFilteredCards);
startActivity(intent);
The main part to consider is when I pass mTopic. This is a Topic interface that I created.
However, the Topic interface extends Parcelable and so the objects that implement Topic also include the constructor, CREATOR field, and the methods that a class implementing Parcelable would normally have to have.
You can view the relevant classes via the GitHub links, but I will provide the relevant parts of these classes below. Here is the Topic interface:
public interface Topic extends Parcelable {
int getId();
String getIdentifier();
String getName();
Course getCourse();
ArrayList<FlashCard> getFlashCards(Context context);
class FlashCardsRetriever {
public static ArrayList<FlashCard> filterStandardCards(ArrayList<FlashCard> flashCards, #StandardFlashCard.ContentType int contentType) {
ArrayList<FlashCard> filteredCards = new ArrayList<>();
for (FlashCard flashCard : flashCards) {
boolean isPaper2 = ((StandardFlashCard) flashCard).isPaper2();
boolean condition;
switch (contentType) {
case StandardFlashCard.PAPER_1:
condition = !isPaper2;
break;
case StandardFlashCard.PAPER_2:
condition = isPaper2;
break;
case StandardFlashCard.ALL:
condition = true;
break;
default:
throw new IllegalArgumentException("content type '" + contentType + "' is invalid");
}
if (condition) filteredCards.add(flashCard);
}
return filteredCards;
}
...
}
}
A class (object) that implements Topic:
public class CourseTopic implements Topic {
...
public CourseTopic(int id, String identifier, String name, Course course) {
...
}
#Override
public int getId() {
return mId;
}
#Override
public String getIdentifier() {
return mIdentifier;
}
...
protected CourseTopic(Parcel in) {
mId = in.readInt();
mIdentifier = in.readString();
mName = in.readString();
mCourse = in.readParcelable(Course.class.getClassLoader());
}
public static final Parcelable.Creator<CourseTopic> CREATOR = new Parcelable.Creator<CourseTopic>() {
#Override
public CourseTopic createFromParcel(Parcel in) {
return new CourseTopic(in);
}
#Override
public CourseTopic[] newArray(int size) {
return new CourseTopic[size];
}
};
#Override
public int describeContents() {
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeInt(mId);
dest.writeString(mIdentifier);
dest.writeString(mName);
dest.writeParcelable(mCourse, flags);
}
}
In one of the last lines of the code above, you can see I pass mCourse, which is a Course object I created. Here it is:
public class Course implements Parcelable {
...
public Course(String subject, String examBoard, #FlashCard.CourseType String courseType,
String revisionGuide) {
...
}
public String getSubjectIdentifier() {
return mSubjectIdentifier;
}
public String getExamBoardIdentifier() {
return mBoardIdentifier;
}
public ArrayList<Topic> getTopics(Context context) {
ArrayList<Topic> topics = new ArrayList<>();
String filename = mSubjectIdentifier + "_" + mBoardIdentifier + "_topics.csv";
CsvParser parser = CsvUtils.getMyParser();
try {
List<String[]> allRows = parser.parseAll(context.getAssets().open(filename));
for (String[] line : allRows) {
int id = Integer.parseInt(line[0]);
topics.add(new CourseTopic(id, line[1], line[2], this));
}
} catch (IOException e) {
e.printStackTrace();
}
return topics;
}
...
protected Course(Parcel in) {
mSubjectIdentifier = in.readString();
mBoardIdentifier = in.readString();
mCourseType = in.readString();
mRevisionGuide = in.readString();
}
public static final Creator<Course> CREATOR = new Creator<Course>() {
#Override
public Course createFromParcel(Parcel in) {
return new Course(in);
}
#Override
public Course[] newArray(int size) {
return new Course[size];
}
};
#Override
public int describeContents() {
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(mSubjectIdentifier);
dest.writeString(mBoardIdentifier);
dest.writeString(mCourseType);
dest.writeString(mRevisionGuide);
}
}
I suspect something here may be causing the problem, and is the reason my scenario is different from those in other questions.
To be honest, I'm not exactly sure what may be causing the error, so explanations and guidance in answers would be much appreciated.
Edit:
After David Wasser's suggestions, I have updated parts of my code like so:
FlashCardActivity.java - onCreate(...):
Bundle extras = getIntent().getExtras();
extras.setClassLoader(Topic.class.getClassLoader());
mTopic = extras.getParcelable(EXTRA_TOPIC);
Course.java - writeToParcel(...):
dest.writeString(mSubjectIdentifier);
dest.writeString(mBoardIdentifier);
dest.writeString(mCourseType);
dest.writeInt(mRevisionGuide == null ? 0 : 1);
if (mRevisionGuide != null) dest.writeString(mRevisionGuide);
Course.java - Course(Parcel in):
mSubjectIdentifier = in.readString();
mBoardIdentifier = in.readString();
mCourseType = in.readString();
if (in.readInt() != 0) mRevisionGuide = in.readString();
I've added log messages using Log.d(...) to see if any variables are null when being passed in writeToParcel(...) and used David Wasser's method to properly handle this.
I still get the same error message, however.

Your problem is in LanguagesFlashCard. Here are your parcel/unparcel methods:
protected LanguagesFlashCard(Parcel in) {
mId = in.readInt();
mEnglish = in.readString();
mAnswerPrefix = in.readString();
mAnswer = in.readString();
mTier = in.readInt();
mTopic = in.readParcelable(Topic.class.getClassLoader());
}
As you can see, they don't match. The second item you write to the Parcel is an int, the second item you read from the Parcel is a String.
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeInt(mId);
dest.writeInt(mTier);
dest.writeString(mEnglish);
dest.writeString(mAnswerPrefix);
dest.writeString(mAnswer);
dest.writeParcelable(mTopic, flags);
}

Kotlin code for sub data class like ImagesModel also parcelable used
data class MyPostModel(
#SerializedName("post_id") val post_id: String? = "",
#SerializedName("images") val images: ArrayList<ImagesModel>? = null
): Parcelable {
constructor(parcel: Parcel) : this(
parcel.writeString(post_id)
parcel.createTypedArrayList(ImagesModel.CREATOR)
)
override fun writeToParcel(parcel: Parcel, flags: Int) {
parcel.writeString(post_id)
parcel.writeTypedList(images)
}
}

Parcelable Object return BadParcelableException: ClassNotFoundException when obj = getIntent().getParcelableExtra("name")

I have a problem when I write pracelable object and receive from another application that I wrote.
Everytime when I tried to get the object it always turned out to be BadParcelableException: ClassNotFoundException when unmarshalling.
I've been looking around and wonder if it turned out bad when I send to another application.
Or it's simply I had error in my codes.
Please tell me where did I go wrong.
my sending lines:
ParcelableObject myObject = new ParcelableObject();
myObject = new ParcelableObject(result_name, resut_lv, result_race,
result_job, result_nation, result_guild, result_mission);
intent.putExtra("ACTION_DATA_TRANSFER", myObject);
intent.setClassName(target_app, target_app+".ReceiveMain");
startActivity(intent);
my receive lines:
ParcelableObject myObject = new ParcelableObject();
myObject = getIntent().getParcelableExtra("ACTION_DATA_TRANSFER"); //always crashed at this line
if (getIntent().hasExtra("ACTION_DATA_TRANSFER")) {
Log.w("****CHECKING****", myObject.getName());
item1.setText("The Character's name is: " + myObject.getName());
} else {
Toast.makeText(getApplicationContext(), "There is not data passed yet",
Toast.LENGTH_LONG).show();
}
my ParcelableObject class:
private String name;
private int lv;
private String race;
private String job;
private String nation;
private String guild;
public String mission;
public void setName(String name) {
this.name = name;
}
public void setLv(int lv) {
this.lv = lv;
}
public void setRace(String race) {
this.race = race;
}
public void setJob(String job) {
this.job = job;
}
public void setNation(String nation) {
this.nation = nation;
}
public void setGuild(String guild) {
this.guild = guild;
}
public void setMission(String mission) {
this.mission = mission;
}
public ParcelableObject(String name, int lv, String race, String job, String
nation, String guild, String mission) {
// TODO Auto-generated constructor stub
this.name = name;
this.lv = lv;
this.race = race;
this.job = job;
this.nation = nation;
this.guild = guild;
this.mission = mission;
}
public String getName() {
return name;
}
public int getLv() {
return lv;
}
public String getRace() {
return race;
}
public String getJob() {
return job;
}
public String getNation() {
return nation;
}
public String getGuild() {
return guild;
}
public String getMission() {
return mission;
}
#Override
public int describeContents() {
// TODO Auto-generated method stub
Log.w("****PO CHECKING****", "describeContents called");
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
// TODO Auto-generated method stub
Log.w("****PO CHECKING****", "writeToParcel called");
dest.writeString(name);
dest.writeString(job);
dest.writeInt(lv);
dest.writeString(race);
dest.writeString(guild);
dest.writeString(nation);
dest.writeString(mission);
}
public ParcelableObject() {
// TODO Auto-generated constructor stub
super();
Log.i("**check if exist**", "start parcel");
}
public static final Parcelable.Creator<ParcelableObject> CREATOR =
new Parcelable.Creator<ParcelableObject>() {
#Override
public ParcelableObject createFromParcel(Parcel in) {
// TODO Auto-generated method stub
Log.w("checking out", "createFromParcel");
ParcelableObject pObject = new ParcelableObject();
pObject.name = in.readString();
pObject.job = in.readString();
pObject.lv = in.readInt();
pObject.race = in.readString();
pObject.guild = in.readString();
pObject.nation = in.readString();
pObject.mission = in.readString();
return pObject;
}
#Override
public ParcelableObject[] newArray(int size) {
// TODO Auto-generated method stub
return new ParcelableObject[size];
}
};
EDIT:
To clarify before some people think I am a lazy noob, I have been looking for answer to solve the cause for this but without any luck. I looked up many people's code and tested out many times but still can't get my app right. So that is why I am here to ask help. If some people still think I am a lazy noob, I guess I am too lazy for some people to draw that conclusion. I should reconsider of my action again.
My situation is:
I wrote 2 apps and one is sending a parcelable object to another application. First app it's working correctly to send the object to another. However, as the second app receive it, it goes wrong and gives out the BadParcelableException as I run the process. I am not using bundle because I saw many examples that it is not necessary to do so. If I have been wrong please correct me.

I found the answer that related to this topic...
Is using Parcelable the right way to send data between applications?
Thank you all for the comments from above....

I've solved my case by using serializable instead of Parcelable.
but in your case here try parsing the object like this
myObject = (ParcelableObject)getIntent().getParcelableExtra("ACTION_DATA_TRANSFER");

How to pass List via intent from one activity to another activity in android using xamarin

i am new to Xamarin. I need to pass List of data as from one activity to another activity via intent .and get those data in another activity screen and process those data's. Please suggest a solution.
Thanks in advance

Use IList of generic type to pass data to the required data from one activity to another.
IList<String> Mon_year = new List<String>();
then pass this List in the intent
i.PutStringArrayListExtra("month_year",Mon_year);
In Another activity(where you want to get the sent data)
IList<String> Mon_year = Intent.GetStringArrayListExtra("month_year") ;// here u get the Ilist of String data...

I approached this a bit differently. I created a base class which inherited from Java.Lang.Object, ISerializable so that I could use Bundle.PutSerializable(string key, ISerializable value) to pass my objects between Activities.
[Flags]
public enum ObjectState
{
Normal = 0,
New = 1,
Modified = 2,
Removed = 4
}
public abstract class ObjectBase : Java.Lang.Object, ISerializable
{
public Guid Id { get; set; }
public ObjectState State { get; set; }
protected ObjectBase(IntPtr handle, JniHandleOwnership transfer) : base(handle, transfer)
{
}
protected ObjectBase()
{
}
[Export("readObject", Throws = new[] { typeof(IOException), typeof(Java.Lang.ClassNotFoundException) })]
private void ReadObject(ObjectInputStream stream)
{
this.Deserialize(stream);
}
[Export("writeObject", Throws = new[] { typeof(IOException), typeof(Java.Lang.ClassNotFoundException) })]
private void WriteObject(ObjectOutputStream stream)
{
this.Serialize(stream);
}
protected virtual void Deserialize(ObjectInputStream stream)
{
this.Id = Guid.Parse(stream.ReadUTF());
this.State = (ObjectState)stream.ReadInt();
}
protected virtual void Serialize(ObjectOutputStream stream)
{
stream.WriteUTF(this.Id.ToString());
stream.WriteInt((int)this.State);
}
}
public class Person : ObjectBase
{
public string Name { get; set; }
public int Age { get; set; }
public bool IsMarried { get; set; }
public DateTime? Anniversary { get; set; }
protected override void Deserialize(ObjectInputStream stream)
{
base.Deserialize(stream);
if (stream.ReadBoolean())
this.Name = stream.ReadUTF();
this.Age = stream.ReadInt();
this.IsMarried = stream.ReadBoolean();
if (stream.ReadBoolean())
this.Anniversary = DateTime.Parse(stream.ReadUTF());
}
protected override void Serialize(ObjectOutputStream stream)
{
base.Serialize(stream);
stream.WriteBoolean(this.Name != null);
if (this.Name != null)
stream.WriteUTF(this.Name);
stream.WriteInt(this.Age);
stream.WriteBoolean(this.IsMarried);
stream.WriteBoolean(this.Anniversary != null);
if (this.Anniversary != null)
stream.WriteUTF(this.Anniversary.Value.ToString(CultureInfo.InvariantCulture));
}
}
I can then pass a list of Person objects to a new Activity by doing:
List<Person> persons = new List<Person>();
var intent = new Intent(this, typeof(MyActivity));
var bundle = new Bundle();
for (int i = 0; i < persons.Count; i++)
{
var p = persons[i];
bundle.PutSerializable("Person" + i, p);
}
intent.PutExtras(bundle);
this.StartActivity(intent);
Then Recieve the objects like so:
protected override void OnCreate(Bundle bundle)
{
List<Person> persons = new List<Person>();
int i = 0;
while (bundle.ContainsKey("Person" + i))
{
var p = (Person) bundle.GetSerializable("Person" + i);
persons.Add(p);
i++;
}
base.OnCreate(bundle);
}

For passing a list of content from one activity to other activity you can use parcelable class. Its a type of bundle in which we can pass any type of content from one activity to other activity. The only thing is you just need to customize the parcelable class according to your need.
Please visit this Link or download this sample project so that you can understand more about passing list of content from one activity to other activity.
Hope this will solve your problem.

How to pass ArrayList of Objects from one to another activity using Intent in android?

I have the following in code in my onClick() method as
List<Question> mQuestionsList = QuestionBank.getQuestions();
Now I have the intent after this line, as follows :
Intent resultIntent = new Intent(this, ResultActivity.class);
resultIntent.putParcelableArrayListExtra("QuestionsExtra", (ArrayList<? extends Parcelable>) mQuestionsList);
startActivity(resultIntent);
I don't know how to pass this question lists in the intent from one activity to another activity
My Question class
public class Question {
private int[] operands;
private int[] choices;
private int userAnswerIndex;
public Question(int[] operands, int[] choices) {
this.operands = operands;
this.choices = choices;
this.userAnswerIndex = -1;
}
public int[] getChoices() {
return choices;
}
public void setChoices(int[] choices) {
this.choices = choices;
}
public int[] getOperands() {
return operands;
}
public void setOperands(int[] operands) {
this.operands = operands;
}
public int getUserAnswerIndex() {
return userAnswerIndex;
}
public void setUserAnswerIndex(int userAnswerIndex) {
this.userAnswerIndex = userAnswerIndex;
}
public int getAnswer() {
int answer = 0;
for (int operand : operands) {
answer += operand;
}
return answer;
}
public boolean isCorrect() {
return getAnswer() == choices[this.userAnswerIndex];
}
public boolean hasAnswered() {
return userAnswerIndex != -1;
}
#Override
public String toString() {
StringBuilder builder = new StringBuilder();
// Question
builder.append("Question: ");
for(int operand : operands) {
builder.append(String.format("%d ", operand));
}
builder.append(System.getProperty("line.separator"));
// Choices
int answer = getAnswer();
for (int choice : choices) {
if (choice == answer) {
builder.append(String.format("%d (A) ", choice));
} else {
builder.append(String.format("%d ", choice));
}
}
return builder.toString();
}
}

Between Activity: Worked for me
ArrayList<Object> object = new ArrayList<Object>();
Intent intent = new Intent(Current.class, Transfer.class);
Bundle args = new Bundle();
args.putSerializable("ARRAYLIST",(Serializable)object);
intent.putExtra("BUNDLE",args);
startActivity(intent);
In the Transfer.class
Intent intent = getIntent();
Bundle args = intent.getBundleExtra("BUNDLE");
ArrayList<Object> object = (ArrayList<Object>) args.getSerializable("ARRAYLIST");
Hope this help's someone.
Using Parcelable to pass data between Activity
This usually works when you have created DataModel
e.g. Suppose we have a json of type
{
"bird": [{
"id": 1,
"name": "Chicken"
}, {
"id": 2,
"name": "Eagle"
}]
}
Here bird is a List and it contains two elements so
we will create the models using jsonschema2pojo
Now we have the model class Name BirdModel and Bird
BirdModel consist of List of Bird
and Bird contains name and id
Go to the bird class and add interface "implements Parcelable"
add implemets method in android studio by Alt+Enter
Note: A dialog box will appear saying Add implements method
press Enter
The add Parcelable implementation by pressing the Alt + Enter
Note: A dialog box will appear saying Add Parcelable implementation
and Enter again
Now to pass it to the intent.
List<Bird> birds = birdModel.getBird();
Intent intent = new Intent(Current.this, Transfer.class);
Bundle bundle = new Bundle();
bundle.putParcelableArrayList("Birds", birds);
intent.putExtras(bundle);
startActivity(intent);
And on Transfer Activity onCreate
List<Bird> challenge = this.getIntent().getExtras().getParcelableArrayList("Birds");
Thanks
If there is any problem please let me know.

Steps:
Implements your object class to serializable
public class Question implements Serializable`
Put this in your Source Activity
ArrayList<Question> mQuestionList = new ArrayList<Question>;
mQuestionsList = QuestionBank.getQuestions();
mQuestionList.add(new Question(ops1, choices1));
Intent intent = new Intent(SourceActivity.this, TargetActivity.class);
intent.putExtra("QuestionListExtra", mQuestionList);
Put this in your Target Activity
ArrayList<Question> questions = new ArrayList<Question>();
questions = (ArrayList<Questions>) getIntent().getSerializableExtra("QuestionListExtra");

It works well,
public class Question implements Serializable {
private int[] operands;
private int[] choices;
private int userAnswerIndex;
public Question(int[] operands, int[] choices) {
this.operands = operands;
this.choices = choices;
this.userAnswerIndex = -1;
}
public int[] getChoices() {
return choices;
}
public void setChoices(int[] choices) {
this.choices = choices;
}
public int[] getOperands() {
return operands;
}
public void setOperands(int[] operands) {
this.operands = operands;
}
public int getUserAnswerIndex() {
return userAnswerIndex;
}
public void setUserAnswerIndex(int userAnswerIndex) {
this.userAnswerIndex = userAnswerIndex;
}
public int getAnswer() {
int answer = 0;
for (int operand : operands) {
answer += operand;
}
return answer;
}
public boolean isCorrect() {
return getAnswer() == choices[this.userAnswerIndex];
}
public boolean hasAnswered() {
return userAnswerIndex != -1;
}
#Override
public String toString() {
StringBuilder builder = new StringBuilder();
// Question
builder.append("Question: ");
for(int operand : operands) {
builder.append(String.format("%d ", operand));
}
builder.append(System.getProperty("line.separator"));
// Choices
int answer = getAnswer();
for (int choice : choices) {
if (choice == answer) {
builder.append(String.format("%d (A) ", choice));
} else {
builder.append(String.format("%d ", choice));
}
}
return builder.toString();
}
}
In your Source Activity, use this :
List<Question> mQuestionList = new ArrayList<Question>;
mQuestionsList = QuestionBank.getQuestions();
mQuestionList.add(new Question(ops1, choices1));
Intent intent = new Intent(SourceActivity.this, TargetActivity.class);
intent.putExtra("QuestionListExtra", ArrayList<Question>mQuestionList);
In your Target Activity, use this :
List<Question> questions = new ArrayList<Question>();
questions = (ArrayList<Question>)getIntent().getSerializableExtra("QuestionListExtra");

Your bean or pojo class should implements parcelable interface.
For example:
public class BeanClass implements Parcelable{
String name;
int age;
String sex;
public BeanClass(String name, int age, String sex) {
this.name = name;
this.age = age;
this.sex = sex;
}
public static final Creator<BeanClass> CREATOR = new Creator<BeanClass>() {
#Override
public BeanClass createFromParcel(Parcel in) {
return new BeanClass(in);
}
#Override
public BeanClass[] newArray(int size) {
return new BeanClass[size];
}
};
#Override
public int describeContents() {
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(name);
dest.writeInt(age);
dest.writeString(sex);
}
}
Consider a scenario that you want to send the arraylist of beanclass type from Activity1 to Activity2.
Use the following code
Activity1:
ArrayList<BeanClass> list=new ArrayList<BeanClass>();
private ArrayList<BeanClass> getList() {
for(int i=0;i<5;i++) {
list.add(new BeanClass("xyz", 25, "M"));
}
return list;
}
private void gotoNextActivity() {
Intent intent=new Intent(this,Activity2.class);
/* Bundle args = new Bundle();
args.putSerializable("ARRAYLIST",(Serializable)list);
intent.putExtra("BUNDLE",args);*/
Bundle bundle = new Bundle();
bundle.putParcelableArrayList("StudentDetails", list);
intent.putExtras(bundle);
startActivity(intent);
}
Activity2:
ArrayList<BeanClass> listFromActivity1=new ArrayList<>();
listFromActivity1=this.getIntent().getExtras().getParcelableArrayList("StudentDetails");
if (listFromActivity1 != null) {
Log.d("listis",""+listFromActivity1.toString());
}
I think this basic to understand the concept.

Pass your object via Parcelable.
And here is a good tutorial to get you started.
First Question should implements Parcelable like this and add the those lines:
public class Question implements Parcelable{
public Question(Parcel in) {
// put your data using = in.readString();
this.operands = in.readString();;
this.choices = in.readString();;
this.userAnswerIndex = in.readString();;
}
public Question() {
}
#Override
public int describeContents() {
// TODO Auto-generated method stub
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(operands);
dest.writeString(choices);
dest.writeString(userAnswerIndex);
}
public static final Parcelable.Creator<Question> CREATOR = new Parcelable.Creator<Question>() {
#Override
public Question[] newArray(int size) {
return new Question[size];
}
#Override
public Question createFromParcel(Parcel source) {
return new Question(source);
}
};
}
Then pass your data like this:
Question question = new Question();
// put your data
Intent resultIntent = new Intent(this, ResultActivity.class);
resultIntent.putExtra("QuestionsExtra", question);
startActivity(resultIntent);
And get your data like this:
Question question = new Question();
Bundle extras = getIntent().getExtras();
if(extras != null){
question = extras.getParcelable("QuestionsExtra");
}
This will do!

The easiest way to pass ArrayList using intent
Add this line in dependencies block build.gradle.
implementation 'com.google.code.gson:gson:2.2.4'
pass arraylist
ArrayList<String> listPrivate = new ArrayList<>();
Intent intent = new Intent(MainActivity.this, ListActivity.class);
intent.putExtra("private_list", new Gson().toJson(listPrivate));
startActivity(intent);
retrieve list in another activity
ArrayList<String> listPrivate = new ArrayList<>();
Type type = new TypeToken<List<String>>() {
}.getType();
listPrivate = new Gson().fromJson(getIntent().getStringExtra("private_list"), type);
You can use object also instead of String in type
Works for me..

Simple as that !! worked for me
From activity
Intent intent = new Intent(Viewhirings.this, Informaall.class);
intent.putStringArrayListExtra("list",nselectedfromadapter);
startActivity(intent);
TO activity
Bundle bundle = getIntent().getExtras();
nselectedfromadapter= bundle.getStringArrayList("list");

If your class Question contains only primitives, Serializeble or String fields you can implement him Serializable. ArrayList is implement Serializable, that's why you can put it like Bundle.putSerializable(key, value) and send it to another Activity.
IMHO, Parcelable - it's very long way.

I do one of two things in this scenario
Implement a serialize/deserialize system for my objects and pass them as Strings (in JSON format usually, but you can serialize them any way you'd like)
Implement a container that lives outside of the activities so that all my activities can read and write to this container. You can make this container static or use some kind of dependency injection to retrieve the same instance in each activity.
Parcelable works just fine, but I always found it to be an ugly looking pattern and doesn't really add any value that isn't there if you write your own serialization code outside of the model.

You must need to also implement Parcelable interface and must add writeToParcel method to your Questions class with Parcel argument in Constructor in addition to Serializable. otherwise app will crash.

Your arrayList:
ArrayList<String> yourArray = new ArrayList<>();
Write this code from where you want intent:
Intent newIntent = new Intent(this, NextActivity.class);
newIntent.putExtra("name",yourArray);
startActivity(newIntent);
In Next Activity:
ArrayList<String> myArray = new ArrayList<>();
Write this code in onCreate:
myArray =(ArrayList<String>)getIntent().getSerializableExtra("name");

To set the data in kotlin
val offerIds = ArrayList<Offer>()
offerIds.add(Offer(1))
retrunIntent.putExtra(C.OFFER_IDS, offerIds)
To get the data
val offerIds = data.getSerializableExtra(C.OFFER_IDS) as ArrayList<Offer>?
Now access the arraylist

Implements Parcelable and send arraylist as putParcelableArrayListExtra and get it from next activity getParcelableArrayListExtra
example:
Implement parcelable on your custom class -(Alt +enter) Implement its methods
public class Model implements Parcelable {
private String Id;
public Model() {
}
protected Model(Parcel in) {
Id= in.readString();
}
public static final Creator<Model> CREATOR = new Creator<Model>() {
#Override
public ModelcreateFromParcel(Parcel in) {
return new Model(in);
}
#Override
public Model[] newArray(int size) {
return new Model[size];
}
};
public String getId() {
return Id;
}
public void setId(String Id) {
this.Id = Id;
}
#Override
public int describeContents() {
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(Id);
}
}
Pass class object from activity 1
Intent intent = new Intent(Activity1.this, Activity2.class);
intent.putParcelableArrayListExtra("model", modelArrayList);
startActivity(intent);
Get extra from Activity2
if (getIntent().hasExtra("model")) {
Intent intent = getIntent();
cartArrayList = intent.getParcelableArrayListExtra("model");
}

Your intent creation seems correct if your Question implements Parcelable.
In the next activity you can retrieve your list of questions like this:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(getIntent() != null && getIntent().hasExtra("QuestionsExtra")) {
List<Question> mQuestionsList = getIntent().getParcelableArrayListExtra("QuestionsExtra");
}
}

You can pass the arraylist from one activity to another by using bundle with intent.
Use the code below
This is the shortest and most suitable way to pass arraylist
bundle.putStringArrayList("keyword",arraylist);

I found that most of the answers work but with a warning. So I have a tricky way to achieve this without any warning.
ArrayList<Question> questionList = new ArrayList<>();
...
Intent intent = new Intent(CurrentActivity.this, ToOpenActivity.class);
for (int i = 0; i < questionList.size(); i++) {
Question question = questionList.get(i);
intent.putExtra("question" + i, question);
}
startActivity(intent);
And now in Second Activity
ArrayList<Question> questionList = new ArrayList<>();
Intent intent = getIntent();
int i = 0;
while (intent.hasExtra("question" + i)){
Question model = (Question) intent.getSerializableExtra("question" + i);
questionList.add(model);
i++;
}
Note:
implements Serializable in your Question class.

You can use parcelable for object passing which is more efficient than Serializable .
Kindly refer the link which i am share contains complete parcelable sample.
Click download ParcelableSample.zip

You can Pass Arraylist/Pojo using bundle like this ,
Intent intent = new Intent(MainActivity.this, SecondActivity.class);
Bundle args = new Bundle();
args.putSerializable("imageSliders",(Serializable)allStoriesPojo.getImageSliderPojos());
intent.putExtra("BUNDLE",args);
startActivity(intent);
Get those values in SecondActivity like this
Intent intent = getIntent();
Bundle args = intent.getBundleExtra("BUNDLE");
String filter = bundle.getString("imageSliders");

You can try this. I think it will help you.
Don't fotget to Initialize value into ArrayList
ArrayList<String> imageList = new ArrayList<>();
Send data using intent.putStringArrayListExtra()....
Intent intent = new Intent(this, NextActivity.class);
intent.putStringArrayListExtra("IMAGE_LIST", imageList);
startActivity(intent);
Receive data using intent.getStringArrayListExtra()...
ArrayList<String> imageList = new ArrayList<>();
Intent intent = getIntent();
imageList = intent.getStringArrayListExtra("IMAGE_LIST");

As we know getSerializable() is deprecated so we can use other easy way to transfer array between activities or between fragment to activities:
First initialize Array of Cars:
private var carsList = ArrayList<Cars>()
On sending Activity/Fragment side:
val intent = Intent(mContext, SearchActivity::class.java)
intent.putExtra("cars_list", Gson().toJson(carsList))
startActivity(intent)
On Receiving Activity:
val type: Type = object : TypeToken<List<CarsModel?>?>() {}.type
categoryList = Gson().fromJson(intent.getStringExtra("cars_list"), type)

I had the exact same question and while still hassling with the Parcelable, I found out that the static variables are not such a bad idea for the task.
You can simply create a
public static ArrayList<Parliament> myObjects = ..
and use it from elsewhere via MyRefActivity.myObjects
I was not sure about what public static variables imply in the context of an application with activities. If you also have doubts about either this or on performance aspects of this approach, refer to:
What's the best way to share data between activities?
Using static variables in Android
Cheers.

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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