Serializable vs Parcelable

Serializable-Java

cons

• reflection - slow
• standard Java interface

• creates a lot of temporary objects and causes quite a bit of garbage collection

  pros

• easier to implement

public class ItemSerializable implements Serializable {
    private String name;
    private int age;
    public ArrayList<String> address;
    public ItemSerializable(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 int getAge() {
        return age;
    }
}

Parcelable

cons

• takes more time to implement

pros

• faster
• array can be passed via Intent in android
• no reflection, 选择字段读写
• kotlin有注解

@Parcelize
data class Item(
        val title: String,
        val price: Double,
        val imageUrl: String,
        val category: Category
) : Parcelable
@Parcelize
data class Category(
        val tag: String
) : Parcelable

• java编写稍微复杂

public class ItemParcelable implements Parcelable {
    private int age;
    private String name;
    private ArrayList<String> address;
    public ItemParcelable(String name, int age, ArrayList<String> address) {
        this.name = name;
        this.age = age;
        this.address = address;
    }
    public ItemParcelable(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<ItemParcelable> CREATOR = new Creator<ItemParcelable>() {
        @Override
        public ItemParcelable[] newArray(int size) {
            return new ItemParcelable[size];
        }
        @Override
        public ItemParcelable createFromParcel(Parcel source) {
            return new ItemParcelable(source);
        }
    };
}

construct

Class clazz = Class.forName(activity);
Intent intent = new Intent(MainActivity.this.getApplicationContext(), clazz);
Item item = new Item("hello", 888, "testing", new Category("tag"));
intent.putExtra("primitive Int", 888);
intent.putExtra("item",item);
ArrayList<String> arrayList = new ArrayList<>();
arrayList.add("dddddddd");
ItemParcelable mObjects = new ItemParcelable("name", 99, arrayList);
intent.putExtra("itemParcelable",mObjects);
ItemSerializable itemSerializable = new ItemSerializable("name", 99, arrayList);
intent.putExtra("itemSerializable", itemSerializable);
startActivity(intent);

getdata

        val item = intent.getParcelableExtra<Item>("item")
        val java = intent.getParcelableExtra<ItemParcelable>("itemParcelable")
        val itemSerializable = intent.getSerializableExtra("itemSerializable") as ItemSerializable