Android——如何使用AIDL？

1. AIDL支持的数据类型

• 支持除short以外的java基本数据类型，之所以不支持short数据类型，是因为Parcel无法对short类型进行序列化，也就无法通过AIDL将short类型的数据在客户端和服务器端传输。
• String,CharSequence
• List，接收方必须是ArrayList
• Map，接收方必须是HashMap
• 其他AIDL定义的AIDL接口
• 实现Parcelable的类

2. 服务端的实现

2.1 定义用于传输的类型

如果你想传输一个自定义的类，这个类需要继承自Parcelable，并且还需要定义一个相应的AIDL文件，用来声明已经实现了Parcelable接口的数据类型。
首先是先创建一个用来声明的AIDL文件，有了这样的声明，就可以在对应的AIDL文件中使用Goods类型：

// Goods.aidl
package com.baijimao.goodsaidlserver;

// Declare any non-default types here with import statements

parcelable Goods;

同时还要定义用于传输的实现了Parcelable接口的类Goods：

package com.baijimao.goodsaidlserver;

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

/**
 * @author: baijimao
 * @date: 2019/5/11
 * Description:
 */
public class Goods implements Parcelable {

    private String name;

    private double price;

    public Goods(String name, double price) {
        this.name = name;
        this.price = price;
    }

    public String getName() {
        return name;
    }

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

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "Goods{" +
                "name='" + name + '\'' +
                ", price=" + price +
                '}';
    }

    protected Goods(Parcel in) {
        name = in.readString();
        price = in.readDouble();
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(name);
        dest.writeDouble(price);
    }

    public void readFromParcel(Parcel dest) {
        name = dest.readString();
        price = dest.readDouble();
    }

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

    public static final Creator<Goods> CREATOR = new Creator<Goods>() {
        @Override
        public Goods createFromParcel(Parcel in) {
            return new Goods(in);
        }

        @Override
        public Goods[] newArray(int size) {
            return new Goods[size];
        }
    };
}

2.2 定义操作数据的AIDL接口

这里我们需要定义一个用于操作Goods数据的接口：

// IGoodsOrderItf.aidl
package com.baijimao.goodsaidlserver;

// Declare any non-default types here with import statements
import com.baijimao.goodsaidlserver.Goods;

interface IGoodsOrderItf {
	// 获取商品列表
    List<Goods> getGoodsList();
	// 添加新的商品，关于方法内参数标记in out 或者inout，可以自行百度了解一下
    void addGoods(in Goods goods);
}

定义的AIDL文件路径如下：

2.3 在服务中实现这个接口

当客户端绑定服务的时候，服务返回一个实现了AIDL接口的对象。

package com.baijimao.goodsaidlserver;

// import ...

public class GoodsOrderService extends Service {
    private static final String TAG = "Server";

    List<Goods> goodsList;

    public GoodsOrderService() {
    }

    @Override
    public void onCreate() {
        super.onCreate();
        goodsList = new ArrayList<>();
        initGoodsOrder();
    }

    private void initGoodsOrder() {
        Goods goods = new Goods("可口可乐", 3);
        goodsList.add(goods);
        goods = new Goods("乐事薯片", 12.8);
        goodsList.add(goods);
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        return stub;
    }

    private final IGoodsOrderItf.Stub stub = new IGoodsOrderItf.Stub() {
        @Override
        public List<Goods> getGoodsList() throws RemoteException {
            return goodsList;
        }

        @Override
        public void addGoods(Goods goods) throws RemoteException {
            if (goods != null) {
                goodsList.add(goods);
            } else {
                Log.e(TAG, "传过来一个空商品");
            }
        }
    };
}

3. 客户端的实现

3.1 客户端将服务端的数据搬过来

客户端是如何知道服务端有哪些数据及接口的呢？我们的做法是将服务端定义的AIDL复制到客户端，保持包路径不变，同时也将定义的传输类型也复制到客户端，保持路径不变。

3.2 客户端的实现

创建客户端操作的布局文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/btn_get_goodsorder"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="获取商品订单"/>

    <Button
        android:id="@+id/btn_add_goods"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="增加新商品"/>

    
    <TextView
        android:id="@+id/text_show_goods"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

LinearLayout>

MainActivity去绑定服务，调用服务端的实现去进行完成客户端的功能。

package com.baijimao.goodsaidlclient;

// import ...

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private TextView textView = null;
    private IGoodsOrderItf iGoodsOrderItf;
    private boolean connected = false;
    private List<Goods> goodsList = null;

    private ServiceConnection serviceConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            iGoodsOrderItf = IGoodsOrderItf.Stub.asInterface(service);
            connected = true;
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            connected = false;
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.btn_get_goodsorder).setOnClickListener(this);
        findViewById(R.id.btn_add_goods).setOnClickListener(this);
        textView = findViewById(R.id.text_show_goods);
        connectService();
    }

    private void connectService() {
        Intent intent = new Intent();
        intent.setPackage("com.baijimao.goodsaidlserver");
        intent.setAction("com.baijimao.goodsaidlserver.action");
        bindService(intent, serviceConnection, Context.BIND_AUTO_CREATE);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_get_goodsorder:
                if (connected) {
                    try {
                        goodsList = iGoodsOrderItf.getGoodsList();
                        StringBuilder stringBuilder = new StringBuilder();
                        for (Goods goods : goodsList) {
                            stringBuilder.append(goods.toString() + "\n");
                        }
                        textView.setText(stringBuilder);
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                }
                break;
            case R.id.btn_add_goods:
                if (connected) {
                    Goods goods = new Goods("西瓜", 25);
                    try {
                        iGoodsOrderItf.addGoods(goods);
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                }
                break;
            default:
                break;
        }
    }
}

仅点击查询：

添加完商品后，再点击查询：

致谢：本文是在学习了各位大神的基础上写的，感觉大神们将自己的学习分享出来！！！