Pass Data Using Parecable and Serizable Android

In Android, we cannot just pass objects to activities. To do this the objects must either implement Serializable or Parcelable interface.

Serializable

Serializable is a standard Java interface. You can just implement Serializable interface and add override methods. The problem with this approach is that reflection is used and it is a slow process. This method creates a lot of temporary objects and causes quite a bit of garbage collection. However, Serializable interface is easier to implement.

Look at the example below (Serializable):

// MyObjects Serializable class

import java.io.Serializable;
import java.util.ArrayList;
import java.util.TreeMap;

import android.os.Parcel;
import android.os.Parcelable;

public class MyObjects implements Serializable {

    private String name;
    private int age;
    public ArrayList<String> address;

    public MyObjects(String name, int age, ArrayList<String> address) {
        super();
        this.name = name;
        this.age = age;
        this.address = address;
    }

    public ArrayList<String> getAddress() {
        if (!(address == null))
            return address;
        else
            return new ArrayList<String>();
    }

    public String getName() {
        return name;
    }

    public String getAge() {
        return age;
    }
}

// MyObjects instance
MyObjects mObjects = new MyObjects("name", "age", "Address array here");

// Passing MyObjects instance via intent
Intent mIntent = new Intent(FromActivity.this, ToActivity.class);
mIntent.putExtra("UniqueKey", mObjects);
startActivity(mIntent);

// Getting MyObjects instance
Intent mIntent = getIntent();
MyObjects workorder = (MyObjects)    mIntent.getSerializableExtra("UniqueKey");

Parcelable

Parcelable process is much faster than Serializable. One of the reasons for this is that we are being explicit about the serialization process instead of using reflection to infer it. It also stands to reason that the code has been heavily optimized for this purpose.

Look at the example below (Parcelable):

// MyObjects Parcelable class

import java.util.ArrayList;

import android.os.Parcel;
import android.os.Parcelable;

public class MyObjects implements Parcelable {

    private int age;
    private String name;
    private ArrayList<String> address;

    public MyObjects(String name, int age, ArrayList<String> address) {
        this.name = name;
        this.age = age;
        this.address = address;
    }

    public MyObjects(Parcel source) {
        age = source.readInt();
        name = source.readString();
        address = source.createStringArrayList();
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeInt(age);
        dest.writeString(name);
        dest.writeStringList(address);
    }

    public int getAge() {
        return age;
    }

    public String getName() {
        return name;
    }

    public ArrayList<String> getAddress() {
        if (!(address == null))
            return address;
        else
            return new ArrayList<String>();
    }

    public static final Creator<MyObjects> CREATOR = new Creator<MyObjects>() {
        @Override
        public MyObjects[] newArray(int size) {
            return new MyObjects[size];
        }

        @Override
        public MyObjects createFromParcel(Parcel source) {
            return new MyObjects(source);
        }
    };
}

// MyObjects instance
MyObjects mObjects = new MyObjects("name", "age", "Address array here");

// Passing MyOjects instance
Intent mIntent = new Intent(FromActivity.this, ToActivity.class);
mIntent.putExtra("UniqueKey", mObjects);
startActivity(mIntent);

// Getting MyObjects instance
Intent mIntent = getIntent();
MyObjects workorder = (MyObjects) mIntent.getParcelableExtra("UniqueKey");

You can pass ArrayList of Parcelable objects as below:

// Array of MyObjects
ArrayList<MyObjects> mUsers;

// Passing MyOjects instance
Intent mIntent = new Intent(FromActivity.this, ToActivity.class);
mIntent.putParcelableArrayListExtra("UniqueKey", mUsers);
startActivity(mIntent);

// Getting MyObjects instance
Intent mIntent = getIntent();
ArrayList<MyObjects> mUsers = mIntent.getParcelableArrayList("UniqueKey");

Conclusion

1. Parcelable is faster than Serializable interface
2. Parcelable interface takes more time to implement compared to Serializable interface
3. Serializable interface is easier to implement
4. Serializable interface creates a lot of temporary objects and causes quite a bit of garbage collection
5. Parcelable array can be passed via Intent in android

Use this for Custom Object

public class ResultData implements Parcelable {

public ResultData(Integer id, String name, String tag, String color, List<Criterium> criteria) {
    this.id = id;
    this.name = name;
    this.tag = tag;
    this.color = color;
    this.criteria = criteria;
}

@NonNull
@PrimaryKey()
@SerializedName(value = "id")
@Expose
private Integer id;

@ColumnInfo(name = "name")
@SerializedName("name")
@Expose
private String name;

@ColumnInfo(name = "tag")
@SerializedName("tag")
@Expose
private String tag;

@ColumnInfo(name = "color")
@SerializedName("color")
@Expose
private String color;

@ColumnInfo(name = "ListData")
@TypeConverters(DataTypeConverter.class)
@SerializedName("criteria")
@Expose
private List<Criterium> criteria = new ArrayList<>();

protected ResultData(Parcel in) {
    if (in.readByte() == 0) {
        id = null;
    } else {
        id = in.readInt();
    }
    name = in.readString();
    tag = in.readString();
    color = in.readString();
    in.readTypedList(criteria, Criterium.CREATOR);
}

public static final Creator<ResultData> CREATOR = new Creator<ResultData>() {
    @Override
    public ResultData createFromParcel(Parcel in) {
        return new ResultData(in);
    }
    
    @Override
    public ResultData[] newArray(int size) {
        return new ResultData[size];
    }
};

public Integer getId() {
    return id;
}

public void setId(Integer id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getTag() {
    return tag;
}

public void setTag(String tag) {
    this.tag = tag;
}

public String getColor() {
    return color;
}

public void setColor(String color) {
    this.color = color;
}

public List<Criterium> getCriteria() {
    return criteria;
}

public void setCriteria(List<Criterium> criteria) {
    this.criteria = criteria;
}

@Override
public int describeContents() {
    return 0;
}

@Override
public void writeToParcel(Parcel dest, int flags) {
    
    if (id == null) {
        dest.writeByte((byte) 0);
    } else {
        dest.writeByte((byte) 1);
        dest.writeInt(id);
    }
    dest.writeString(name);
    dest.writeString(tag);
    dest.writeString(color);
    dest.writeTypedList(criteria);
}

public static Creator<ResultData> getCREATOR() {
    return CREATOR;
}
}

Note:- All its Methods and Variable must be Used Parecable

Use this for List<List<String>>

Extending ArrayList and implementing Parcelable on it worked for me.

    public class ParcelableArrayList extends ArrayList<String> implements 
        Parcelable {

    private static final long serialVersionUID = -8516873361351845306L;

    public ParcelableArrayList(){
        super();
    }

    protected ParcelableArrayList(Parcel in) {
        in.readList(this, String.class.getClassLoader());
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeList(this);
    } 

    public static final Parcelable.Creator<ParcelableArrayList> CREATOR = 
            new Parcelable.Creator<ParcelableArrayList>() {
        public ParcelableArrayList createFromParcel(Parcel in) {
            return new ParcelableArrayList(in);
        }

        public ParcelableArrayList[] newArray(int size) {
            return new ParcelableArrayList[size];
        }
    };

}

and Employee class

class Employee implements Parcelable {

    List<ParcelableArrayList> details;
    //.......

    protected Employee(Parcel in) {
        details = new ArrayList<ParcelableArrayList>();
        in.readTypedList(details,ParcelableArrayList.CREATOR);
        //......
    }

    public void writeToParcel(Parcel dest, int flags) {
        dest.writeList(details);
        //.....
    }

    public int describeContents() {
        return 0;
    }

    public static final Parcelable.Creator<Employee> CREATOR = 
            new Parcelable.Creator<Employee>() {
        public Employee createFromParcel(Parcel in) {
            return new Employee(in);
        }

        public Employee[] newArray(int size) {
            return new Employee[size];
        }
    };

    }

Use this for List<List<Object>>.....

Based on comments, I extended the ArrayList class with my custom class and implemented parcelable:

    public class TileList extends ArrayList<Tile> implements Parcelable {

    public TileList(){
        super();
    }

    protected TileList(Parcel in) {
        in.readTypedList(this, Tile.CREATOR);
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel parcel, int i) {
        parcel.writeTypedList(this);
    }

    public static final Parcelable.Creator<TileList> CREATOR = new Parcelable.Creator<TileList>() {
        public TileList createFromParcel(Parcel in) {
            return new TileList(in);
        }

        public TileList[] newArray(int size) {
            return new TileList[size];
        }
    };
    }

and slight changes to my other class:

    public class GameBoard implements Parcelable {
    private String _id;
    public String getId() { return _id; }
    public void setId(String id) { _id = id; }

    private List<TileList> _tiles;
    public List<TileList> getTiles() { return _tiles; }
    public void setTiles(List<TileList> tiles) { _tiles = tiles; }

    public GameBoard(Parcel in) {
        _id = in.readString();
        _tiles = new ArrayList<>();
        in.readTypedList(_tiles, TileList.CREATOR);
    }

    public GameBoard() {

    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel parcel, int i) {
        parcel.writeString(_id);
        parcel.writeTypedList(_tiles);
    }

    public static final Parcelable.Creator<GameBoard> CREATOR = new Parcelable.Creator<GameBoard>() {
        public GameBoard createFromParcel(Parcel in) {
            return new GameBoard(in);
        }

        public GameBoard[] newArray(int size) {
            return new GameBoard[size];
        }
    };
    }

That is all. If any help related to this post please comment.

Thank you, guys.

Enjoy coding.