How to pass ArrayList of Objects from one to anoth

Question

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();
       }

      }

Answer 1

Steps:

1. Implements your object class to serializable

   public class Question implements Serializable`
   

2. 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);
   

3. Put this in your Target Activity

    ArrayList<Question> questions = new ArrayList<Question>();
    questions = (ArrayList<Questions>) getIntent().getSerializableExtra("QuestionListExtra");
   

Answer 2

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!

Answer 3

//arraylist/Pojo you can Pass 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 SecondActivity like this
  Intent intent = getIntent();
        Bundle args = intent.getBundleExtra("BUNDLE");
String filter = bundle.getString("imageSliders");

//Happy coding

Answer 4

I do one of two things in this scenario

1. 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)

2. 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.

Answer 5

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.

Answer 6

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.