Android:Parcelable 和 Serializable 之间的区别? [英] Android: Difference between Parcelable and Serializable?

问题描述

为什么Android提供了2个对象序列化接口?Serializable 对象是否与 Android Binder 和 AIDL 文件互操作?

Why does Android provide 2 interfaces for serializing objects? Do Serializable objects interopt with Android Binder and AIDL files?

推荐答案

在 Android 中，我们不能仅仅将对象传递给活动.为此，对象必须实现 Serializable 或 Parcelable 接口.

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

可序列化

Serializable 是一个标准的 Java 接口.您可以只实现 Serializable 接口并添加覆盖方法.这种方法的问题在于使用了反射，而且这是一个缓慢的过程.此方法会创建大量临时对象并导致相当多的垃圾收集.但是，Serializable 接口更容易实现.

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.

看下面的例子(可序列化):

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;
    }

    // return age
    public int 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");

可包裹

Parcelable 过程比 Serializable 快得多.造成这种情况的原因之一是我们明确说明了序列化过程，而不是使用反射来推断它.代码已为此目的进行了大量优化也是理所当然的.

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.

看下面的例子(Parcelable):

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");

您可以传递 Parcelable 对象的 ArrayList 如下:

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");

结论

1. Parcelable 比 Serializable 接口快
2. Parcelable 接口比 Serializable 接口需要更多时间来实现
3. Serializable 接口更容易实现
4. Serializable 接口创建了很多临时对象并导致相当多的垃圾收集
5. Parcelable 数组可以通过android中的Intent传递

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

这篇关于Android:Parcelable 和 Serializable 之间的区别?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！