零、示例说明

本示例，完成的功能是：客户端向服务端注册一个回调，服务端是一个商店shop，当商店里的产品 Product 有变化时，调用回调向通知客户端，什么商品更新了。

一、完整源代码

完整源码链接: https://github.com/jx0260/TestGradle

二、实现步骤

2.1 定义实体

定义 Product.aidl

// Product.aidl
package com.example.testgradle;// Declare any non-default types here with import statementsparcelable Product;

对应的实体类：

package com.example.testgradle;import android.os.Parcel;
import android.os.Parcelable;public class Product implements Parcelable {private String no;private String name;public String getNo() {return no;}public void setNo(String no) {this.no = no;}public String getName() {return name;}public void setName(String name) {this.name = name;}@Overridepublic int describeContents() {return 0;}@Overridepublic void writeToParcel(Parcel dest, int flags) {dest.writeString(this.no);dest.writeString(this.name);}public void readFromParcel(Parcel source) {this.no = source.readString();this.name = source.readString();}public Product() {}protected Product(Parcel in) {this.no = in.readString();this.name = in.readString();}public static final Creator<Product> CREATOR = new Creator<Product>() {@Overridepublic Product createFromParcel(Parcel source) {return new Product(source);}@Overridepublic Product[] newArray(int size) {return new Product[size];}};
}

定义Callback AIDL，此 IShopProductCallback 将会注册到服务端去。

// IShopProductCallback.aidl
package com.example.testgradle;
import com.example.testgradle.Product;// Declare any non-default types here with import statementsinterface IShopProductCallback {oneway void onProductChanged(in Product product);
}

定义服务端 IShopAidlInterface.aidl，里面有一个registerCallback的方法

// IShopAidlInterface.aidl
package com.example.testgradle;
import com.example.testgradle.IShopProductCallback;// Declare any non-default types here with import statementsinterface IShopAidlInterface {String getProductInfo(int productNo);void buyProduct1(int productNo, String address);oneway void registerCallback(in IShopProductCallback callback);}

2.2 Make project 生成相应的 AIDL实现类

客户端：
在这里插入图片描述
服务端：

2.2 编写客户端

Intent serviceIntent = new Intent("com.example.testgradle.ShopService");
serviceIntent.setPackage("com.example.testgradle");
bindService(serviceIntent, new ServiceConnection() {@Overridepublic void onServiceConnected(ComponentName name, IBinder service) {Log.i(TAG, "onServiceConnected() service=" + service);iShopAidlInterface = IShopAidlInterface.Stub.asInterface(service);try {Log.i(TAG, "Client: register Stub to Server!");iShopAidlInterface.registerCallback(new IShopProductCallback.Stub() {@Overridepublic void onProductChanged(Product product) throws RemoteException {Log.i(TAG, "Client: received product changed -- " + product.getNo() + " name:" + product.getName());}});} catch (RemoteException e) {e.printStackTrace();}}@Overridepublic void onServiceDisconnected(ComponentName name) {}
}, BIND_AUTO_CREATE);

bindService() com.example.testgradle.ShopService ，在 onServiceConnected 回调中，使用拿到的 iShopAidlInterface 对象，调用 registerCallback，注意，此处传入的 callback 是 IShopProductCallback.Stub

public interface IShopProductCallback extends android.os.IInterface
{/** Local-side IPC implementation stub class. */public static abstract class Stub extends android.os.Binder

IShopProductCallback.Stub 继承了 Binder，实际上此处将 IShopProductCallback 的实现传进了参数，到达服务端。服务端拿到的是 IShopProductCallback.Stub.Proxy，这里就会有一种服务端变成客户端的感觉。实际上确实如此，在使用Callback的时候服务端对于Callback来说确实就变成了客户端，将变化的product 提交到服务端（也就是业务上的客户端）
此处，引用的“客户端”，“服务端”是有两套意思，一套是指我们总体业务的客户端、服务端，另一套是指对于callback来说，程序实现的客户端、服务端。

2.3 编写服务端

package com.example.testgradle;import android.app.Service;
import android.content.Intent;
import android.os.Handler;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;import javax.security.auth.login.LoginException;public class ShopService extends Service {private String TAG = "ShopService";private IShopProductCallback mCallback;public ShopService() {}private IShopAidlInterface.Stub mBinder = new IShopAidlInterface.Stub() {@Overridepublic void registerCallback(IShopProductCallback callback) throws RemoteException {Log.i(TAG, "Server: registerCallback() this callback obj is a proxy!");mCallback = callback;mHandler.postDelayed(new Runnable() {@Overridepublic void run() {Product product = new Product();product.setNo("No.0001");product.setName("banana");try {Log.i(TAG, "Server: the proxy obj invoke onProductChanged, pass the product to the client!");mCallback.onProductChanged(product);} catch (RemoteException e) {e.printStackTrace();}}}, 20000);}};@Overridepublic IBinder onBind(Intent intent) {return mBinder;}
}

服务端 public void registerCallback(IShopProductCallback callback) 拿到客户端传来的 callback其实是一个proxy 存到mCallback 本地变量中，20秒后，创建一个变化的Product 调用 mCallback.onProductChanged(product); 将商品信息回调给客户端。

2.4 运行

日志打印：

com.example.testgradle I/ShopService: Server: registerCallback() this callback obj is a proxy!com.example.testgradle I/ShopService: Server: the proxy obj invoke onProductChanged, pass the product to the client!
com.example.clientdemo I/ClientActivity: Client: received product changed -- No.0001 name:banana