Parceable Arraylist of objects

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眼角桃花
眼角桃花 2021-01-24 21:50

I\'m trying to pass an ArrayList of Person Objects from the MainActivity to SecondActivity to print the details of the person in a custom listView adapter.

The applicati

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  • 2021-01-24 22:05

    You should use another function: intent.putParcelableArrayListExtra(String name, ArrayList<? extends Parcelable> value) Google site in main Activity, then intent.getParcelableArrayListExtra to get in second Activity. Hope this help.

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  • 2021-01-24 22:06

    ArrayList does not implements Parcelable, but it implements Serializable, so you can't use getParcelableExtra to receive the data, you must use getSerializableExtra instead.

    ArrayList<Person> person = (ArrayList<Person>) i.getSerializableExtra("personObject");
    

    Person class must implements Serializable too, here is the code example:

    Person implements Serializable{
       private static final long serialVersionUID = 0L;
       String id;
       String name;
    }
    

    Update:

    Another solution: use putParcelableArrayListExtra and getParcelableArrayListExtra.

    First activity:

    ArrayList<Person> list = new ArrayList<Person>();
    
    public void onButtonClick() {
        Intent intent = new Intent(getApplicationContext(), SecondActivity.class);
        intent.putParcelableArrayListExtra("personObject", list);
        startActivity(intent);
    }
    

    Second Activity:

    ArrayList<Person> person = (ArrayList<Person>) i.getParcelableArrayListExtra("personObject");
    

    Note: Parcelable is faster than Serializable, so the second solution is better if you want to pass a lot of data.

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  • 2021-01-24 22:13

    1.Create FirstActivity with one button

    package com.appkart.sdcardconnection;
    
    import java.util.ArrayList;
    
    import android.content.Intent;
    import android.os.Bundle;
    import android.support.v7.app.ActionBarActivity;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.Button;
    
    public class FirstActivity extends ActionBarActivity {
    
        private Button btn;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.first_activity);
    
            btn = (Button) findViewById(R.id.btn);
            btn.setOnClickListener(new OnClickListener() {
    
                @Override
                public void onClick(View v) {
                    Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
                    ArrayList<Person> personList = new ArrayList<Person>();
    
                    personList.add(new Person("10", "Arun"));
                    personList.add(new Person("20", "Ankit"));          
    
                    intent.putExtra("person_list", personList);
                    startActivity(intent);              
                }
            });
        }
    }
    

    2.xml file

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:paddingBottom="@dimen/activity_vertical_margin"
        android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/activity_vertical_margin"
        tools:context="com.appkart.sdcardconnection.FirstActivity" >
    
        <Button
            android:id="@+id/btn"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Second Activity" />
    
    </RelativeLayout>
    

    3.Second Activity

    package com.appkart.sdcardconnection;
    
    import java.util.ArrayList;
    import java.util.List;
    
    import android.app.Activity;
    import android.os.Bundle;
    import android.util.Log;
    
    public class SecondActivity extends Activity {
    
        private static final String TAG = SecondActivity.class.getSimpleName();
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.second_activity);
    
            List<Person> personList = (ArrayList<Person>) getIntent()
                    .getSerializableExtra("person_list");
    
            for (Person person : personList) {
                Log.d(TAG, "id  : " + person.getId());
                Log.d(TAG, "name  : " + person.getName());
    
            }
        }
    }
    

    4.Person POJO

    package com.appkart.sdcardconnection;
    
    import java.io.Serializable;
    
    public class Person implements Serializable {
    
        private String id;
        private String name;
    
        public Person(String id, String name) {
            this.id = id;
            this.name = name;
        }
    
        public String getId() {
            return id;
        }
    
        public void setId(String id) {
            this.id = id;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
    }
    

    Use Serializable instead Parcelable. According to ArrayList java doc it implement Serializable. Array list java doc

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