Android 使用AIDL进行两个APP之间通讯以及相互消息回调(一)

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前言：
AIDL：Android Interface Definition Language，翻译过来就是Android接口定义语言。是用于定义服务器和客户端通信接口的一种描述语言，可以拿来生成用于IPC的代码。所以使用AIDL需要一个服务端和客户端
作用：可以在一个进程中获取另一个进程的数据和调用其暴露出来的方法，从而满足进程间通信的需求。

1.AIDL支持的基本数据类型
八种基本数据类型：byte、char、short、int、long、float、double、boolean
String，CharSequence
实现了Parcelable接口的数据类型
List 类型。List承载的数据必须是AIDL支持的类型，或者是其它声明的AIDL对象
Map类型。Map承载的数据必须是AIDL支持的类型，或者是其它声明的AIDL对象
2.服务端的实现
创建工程，以及所需aidl文件
使用Android Studio新建一个工程,命名为TestAidlDemo1
右键New一个AIDL文件，取名为IAidlInterface，AS会自动在工程目录生成一个路径完全一样的aidl文件夹
既然是要回调消息，那就还需要一个回调接口，同样的方法，创建IAidlCallBack.aidl文件，那么接下来就进行代码编写
实现代码逻辑
编写IAidlInterface.aldi代码，因为我们需要回调消息，那么我们需要注册回调以及注销回调接口，一个发送消息的接口，一个获取历史消息的接口，代码如下(AIDL文件不会自动导包,一些不是基本支持数据类型需要我们自己手动import，)
import com.pgc.testaidldemo1.IAidlCallBack;
interface IAidlInterface {
/**
* Demonstrates some basic types that you can use as parameters
* and return values in AIDL.
*/
void registerCallBack(IAidlCallBack iAidlCallBack);
void unregisterCallBack(IAidlCallBack iAidlCallBack);
void sendMessage(String message);
List getMessages();
}

编写IAidlCallBack.aidl代码：既然是回调接口，那么我们只需要一个消息发送成功的回调接口就行，代码如下

interface IAidlCallBack {
/**
* Demonstrates some basic types that you can use as parameters
* and return values in AIDL.
*/
void onMessageSuccess(String message);
}

既然是服务端，我们需要实现接收消息已经处理消息的逻辑代码，所以我们创建一个AidlService，继承Service,因为Service不能直接接收Callback,但是提供了RemoteCallbackList来注册回调

private RemoteCallbackList callbackList= new RemoteCallbackList<>();
同时RemoteCallbackList提供了beginBroadcast来获取当前注册的回调数，因此我们可以通过这个方法进行回调处理(再使用了beginBroadcast之后必须调用finishBroadcast不然会报beginBroadcast() called while already in a broadcast错误)

final int num=callbackList.beginBroadcast();
for (int i=0;i<num;i++){
IAidlCallBack iAidlCallBack=callbackList.getBroadcastItem(i);
iAidlCallBack.onMessageSuccess(message);
}
callbackList.finishBroadcast();
接下来实例化binder对象并返回给客户端，

@Override
public IBinder onBind(Intent intent) {
return binder;
}

private final IAidlInterface.Stub binder=new IAidlInterface.Stub() {
    @Override
    public void registerCallBack(IAidlCallBack iAidlCallBack) throws RemoteException {
        callbackList.register(iAidlCallBack);
    }

    @Override
    public void unregisterCallBack(IAidlCallBack iAidlCallBack) throws RemoteException {
        callbackList.unregister(iAidlCallBack);
    }

    @Override
    public void sendMessage(String message) throws RemoteException {
        messages.add(message);
        final int num=callbackList.beginBroadcast();
        for (int i=0;i<num;i++){
            IAidlCallBack iAidlCallBack=callbackList.getBroadcastItem(i);
            iAidlCallBack.onMessageSuccess(message);
        }
        callbackList.finishBroadcast();
    }

    @Override
    public List<String> getMessages() throws RemoteException {
        return messages;
    }
};

在AndroidManifest.xml注册Service

AidlService全部代码

package com.pgc.testaidldemo1;

import android.annotation.SuppressLint;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteCallbackList;
import android.os.RemoteException;

import androidx.annotation.Nullable;

import java.util.ArrayList;
import java.util.List;

/**

Created by PengGuiChu on 2020/4/11.
*/
@SuppressLint(“Registered”)
public class AidlService extends Service {
private RemoteCallbackList callbackList= new RemoteCallbackList<>();
private List messages=new ArrayList<>();
@Nullable
@Override
public IBinder onBind(Intent intent) {
return binder;
} private final IAidlInterface.Stub binder=new IAidlInterface.Stub() {
@Override
public void registerCallBack(IAidlCallBack iAidlCallBack) throws RemoteException {
callbackList.register(iAidlCallBack);
} @Override public void unregisterCallBack(IAidlCallBack iAidlCallBack) throws RemoteException { callbackList.unregister(iAidlCallBack); } @Override public void sendMessage(String message) throws RemoteException { messages.add(message); final int num=callbackList.beginBroadcast(); for (int i=0;i<num;i++){ IAidlCallBack iAidlCallBack=callbackList.getBroadcastItem(i); iAidlCallBack.onMessageSuccess(message); } callbackList.finishBroadcast(); } @Override public List<String> getMessages() throws RemoteException { return messages; } }; @Override
public void onCreate() {
super.onCreate();
}
}

因为是服务端和客户端实现相互消息回调，因此在服务端也需要通过binderService来获取binder，相对客户端，因为服务端和AidlService是在同一线程，我们可以直接binderService

Intent intent=new Intent(getApplicationContext(),AidlService.class);
bindService(intent,serviceConnection,BIND_AUTO_CREATE);
然后实例化ServiceConnection

private ServiceConnection serviceConnection=new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName componentName, IBinder iBinder) {

    }

    @Override
    public void onServiceDisconnected(ComponentName componentName) {

    }

};
然后在onServiceConnected中获取binder

iAidlInterface=IAidlInterface.Stub.asInterface(iBinder);
try {
iAidlInterface.asBinder().linkToDeath(mDeathRecipient, 0);//监听进程是否消失
iAidlInterface.registerCallBack(iAidlCallBack);//注册消息回调
messages.addAll(iAidlInterface.getMessages());//获取历史消息
listView.setAdapter(arrayAdapter=new ArrayAdapter<>
(getApplicationContext(),android.R.layout.simple_list_item_1,messages));
} catch (RemoteException e) {
e.printStackTrace();
}
DeathRecipient实例

private IBinder.DeathRecipient mDeathRecipient = new IBinder.DeathRecipient() {
    //当承载IBinder的进程消失时接收回调的接口
    @Override
    public void binderDied() {
        if (null == iAidlInterface) {
            return;
        }
        try {
            iAidlInterface.unregisterCallBack(iAidlCallBack);//注销
        } catch (RemoteException e) {
            e.printStackTrace();
        }
        iAidlInterface.asBinder().unlinkToDeath(mDeathRecipient, 0);
        iAidlInterface = null;
    }
};

iAidlCallBack实例

private IAidlCallBack iAidlCallBack=new IAidlCallBack.Stub() {
    @Override
    public void onMessageSuccess(String message) {
        if (messages!=null&&arrayAdapter!=null){
            messages.add(message);
            handler.sendEmptyMessage(1);
        }
    }
};

MainActivity全部代码

package com.pgc.testaidldemo1;

import android.annotation.SuppressLint;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.RemoteException;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import java.util.ArrayList;
import java.util.List;

import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.OnClick;

public class MainActivity extends AppCompatActivity {
@BindView(R.id.list_view)
ListView listView;
private IAidlInterface iAidlInterface;
private int num;
private List messages=new ArrayList<>();
private ArrayAdapter arrayAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ButterKnife.bind(this);
Intent intent=new Intent(getApplicationContext(),AidlService.class);
bindService(intent,serviceConnection,BIND_AUTO_CREATE);
}

@OnClick(R.id.send_message)
public void onViewClicked(View view) {
    if (iAidlInterface!=null){
        try {
            iAidlInterface.sendMessage("消息"+num);
            num++;
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }
}

private ServiceConnection serviceConnection=new ServiceConnection() {
    @Override
    public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
        iAidlInterface=IAidlInterface.Stub.asInterface(iBinder);
        try {
            iAidlInterface.asBinder().linkToDeath(mDeathRecipient, 0);//监听进程是否消失
            iAidlInterface.registerCallBack(iAidlCallBack);//注册消息回调
            messages.addAll(iAidlInterface.getMessages());//获取历史消息
            listView.setAdapter(arrayAdapter=new ArrayAdapter<>(getApplicationContext(),android.R.layout.simple_list_item_1,messages));
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onServiceDisconnected(ComponentName componentName) {

    }
};

private IBinder.DeathRecipient mDeathRecipient = new IBinder.DeathRecipient() {
    //当承载IBinder的进程消失时接收回调的接口
    @Override
    public void binderDied() {
        if (null == iAidlInterface) {
            return;
        }
        try {
            iAidlInterface.unregisterCallBack(iAidlCallBack);//注销
        } catch (RemoteException e) {
            e.printStackTrace();
        }
        iAidlInterface.asBinder().unlinkToDeath(mDeathRecipient, 0);
        iAidlInterface = null;
    }
};

private IAidlCallBack iAidlCallBack=new IAidlCallBack.Stub() {
    @Override
    public void onMessageSuccess(String message) {
        if (messages!=null&&arrayAdapter!=null){
            messages.add(message);
            handler.sendEmptyMessage(1);
        }
    }
};

@SuppressLint("HandlerLeak")
private Handler handler=new Handler(){
    @Override
    public void handleMessage(@NonNull Message msg) {
        arrayAdapter.notifyDataSetChanged();
    }
};

@Override
protected void onDestroy() {
    //解除注册
    if (null != iAidlInterface && iAidlInterface.asBinder().isBinderAlive()) {
        try {
            iAidlInterface.unregisterCallBack(iAidlCallBack);
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }
    //解除绑定服务
    unbindService(serviceConnection);
    super.onDestroy();
}

}

到此我们的服务端就编码完成，实现效果

3.客户端实现
创建client工程
选中TestAidlDemo1工程右键NEW一个model，命名为client
要想client项目能够连接上Service，我们直接复制上面工程的aidl文件到client工程的main文件里，这样是为了保证两个项目的aidl文件路径一致

而调用逻辑基本和上面MainActivity一样，需要注意一点的是，因为是两个不同进程，在这里我们不能直接bindService来调起服务端，而是通过以下代码实现
Intent intent=new Intent();
String ACTION = “AIDL.service”;//对应服务端AndroidManifest.xml配置service action:name
intent.setAction(ACTION);
intent.setPackage(“com.pgc.testaidldemo1”);//对应服务端AndroidManifest.xml package
bindService(intent,serviceConnection,BIND_AUTO_CREATE);

client的MainActivity全部代码

package com.pgc.client;

import android.annotation.SuppressLint;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.RemoteException;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import com.pgc.testaidldemo1.IAidlCallBack;
import com.pgc.testaidldemo1.IAidlInterface;

import java.util.ArrayList;
import java.util.List;

import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.OnClick;

public class MainActivity extends AppCompatActivity {
@BindView(R.id.list_view)
ListView listView;
private IAidlInterface iAidlInterface;
private int num;
private List messages=new ArrayList<>();
private ArrayAdapter arrayAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ButterKnife.bind(this);
Intent intent=new Intent();
String ACTION = “AIDL.service”;
intent.setAction(ACTION);
intent.setPackage(“com.pgc.testaidldemo1”);
bindService(intent,serviceConnection,BIND_AUTO_CREATE);
}

@OnClick(R.id.send_message)
public void onViewClicked(View view) {
    if (iAidlInterface!=null){
        try {
            iAidlInterface.sendMessage("消息"+num);
            num++;
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }
}

private ServiceConnection serviceConnection=new ServiceConnection() {
    @Override
    public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
        iAidlInterface=IAidlInterface.Stub.asInterface(iBinder);
        try {
            iAidlInterface.asBinder().linkToDeath(mDeathRecipient, 0);
            iAidlInterface.registerCallBack(iAidlCallBack);
            messages.addAll(iAidlInterface.getMessages());
            listView.setAdapter(arrayAdapter=new ArrayAdapter<>(getApplicationContext(),android.R.layout.simple_list_item_1,messages));
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onServiceDisconnected(ComponentName componentName) {

    }
};

private IBinder.DeathRecipient mDeathRecipient = new IBinder.DeathRecipient() {
    //当承载IBinder的进程消失时接收回调的接口
    @Override
    public void binderDied() {
        if (null == iAidlInterface) {
            return;
        }
        iAidlInterface.asBinder().unlinkToDeath(mDeathRecipient, 0);
        iAidlInterface = null;
        //断线重来逻辑
    }
};

private IAidlCallBack iAidlCallBack=new IAidlCallBack.Stub() {
    @Override
    public void onMessageSuccess(String message) {
        if (messages!=null&&arrayAdapter!=null){
            messages.add(message);
            handler.sendEmptyMessage(1);
        }
    }
};

@SuppressLint("HandlerLeak")
private Handler handler=new Handler(){
    @Override
    public void handleMessage(@NonNull Message msg) {
        arrayAdapter.notifyDataSetChanged();
    }
};

@Override
protected void onDestroy() {
    //解除注册
    if (null != iAidlInterface && iAidlInterface.asBinder().isBinderAlive()) {
        try {
            iAidlInterface.unregisterCallBack(iAidlCallBack);
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }
    //解除绑定服务
    unbindService(serviceConnection);
    super.onDestroy();
}

}

运行效果

源码下载地址

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