Android下的IPC通信方式，
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Android下的IPC通信方式，
一、Bundle
Android的Activity、Service、Receiver都支持在Intent传递Bundle数据,Bundle实现了Parcelable接口,
所以能很方便的在不同进程之间进行数据传传输.比如A应用打开B应用的某个Activity,如果要传递自定义的类型,
可以继承自Parcelable接口,参考Parcelable的使用方式 Android序列化的几种实现方式
A页面:
public class MainActivity extends AppCompatActivity {
private final static int OPEN_OTHER_ACTIVITY_REQUEST_CODE = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Intent intent = new Intent();
String packageName = "komine.demos.ipcdemo2";
String activityName = packageName + ".MainActivity";
intent.putExtra("msg","来自komine.demos.ipc传递的参数");
ComponentName componentName = new ComponentName(packageName,activityName);
intent.setComponent(componentName);
startActivityForResult(intent,OPEN_OTHER_ACTIVITY_REQUEST_CODE);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
if(data != null){
if(requestCode == OPEN_OTHER_ACTIVITY_REQUEST_CODE){
Toast.makeText(getApplicationContext(),data.getStringExtra("value"),Toast.LENGTH_SHORT).show();
}
}
}
}
B页面:
public class MainActivity extends AppCompatActivity {
private final static int RESULT_CODE = 0;
private TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = findViewById(R.id.tv);
if(getIntent() != null){
String msg = getIntent().getStringExtra("msg");
textView.setText(msg);
}
}
@Override
public void onBackPressed() {
Intent intent = new Intent();
intent.putExtra("value","来自komine.demos.ipcdemo2的MainActivity页面返回的值");
setResult(RESULT_CODE,intent);
finish();
}
}
二、Messenger
1.基本使用
Messenger是基于AIDL的一种轻量化跨进程通信方式,内部是通过Handler进行消息发送的
首先新建一个MessengerService类
public class MessengerService extends Service implements Handler.Callback {
private static final String TAG = "MessengerService";
public static final int CLIENT_WHAT = 1;
public static final int SERVER_WHAT = 2;
//服务端接收到一条消息就会向客户端发送一条回复消息
@Override
public boolean handleMessage(@NonNull Message msg) {
if (msg.what == CLIENT_WHAT) {
Log.d(TAG, "收到来自客户端的消息:" + msg.getData());
//msg.replyTo是客户端定义的Messenger对象,用来向客户端发送消息
Messenger client = msg.replyTo;
Message replyMessage = Message.obtain(null, SERVER_WHAT);
Bundle bundle = new Bundle();
bundle.putString("reply", "服务端回复客户端的数据..." + new Date());
replyMessage.setData(bundle);
try {
//调用客户端的Messenger对象向客户端发送消息
client.send(replyMessage);
} catch (Exception e) {
e.printStackTrace();
}
}
return false;
}
//服务端的Messenger对象,客户端可以通过onBind中返回的IBinder对象
//来实例化一个Messenger对象,用来向服务端发送Message,Messenger内部采用
//的是Message来进行消息传递,所以需要一个Handler对象来进行消息发送
private final Messenger mMessenger = new Messenger(new Handler(Looper.getMainLooper(),this));
@Nullable
@Override
public IBinder onBind(Intent intent) {
//返回Messenger的Binder对象
return mMessenger.getBinder();
}
}
在AndroidManifest.xml注册MessengerService,该服务运行在另外一个进程中,冒号开头表示在当前进程名之前加上完整的包名,
并且该进程为应用的私有进程,不以冒号开头,则表示全局进程,其他可以通过sharedUserId的方式将自己运行在同一个进程中,比如
sharedUserId = "android.uid.system",将自己运行在系统进程中,以取得系统进程的一些权限,以这种方式运行在一起的进程之间
可以互相访问对方的私有数据,比如data目录、files目录,另外签名要保持一致才行,debug版本不需要.
注册MessengerService
<service android:name="komine.demos.messager.MessengerService" android:process=":remote"/>
MainActivity,布局就一个按钮,绑定了sendMsg方法就不贴代码了
public class MainActivity extends AppCompatActivity implements ServiceConnection,Handler.Callback {
private Messenger mService;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//绑定远程Service
bindService(new Intent(this, MessengerService.class),this,Context.BIND_AUTO_CREATE);
}
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
//通过IBinder对象创建一个Messenger实例
mService = new Messenger(service);
}
//点击发送按钮就会向服务端发送一条Message
public void sendMsg(View view) {
Message msg = Message.obtain(null,MessengerService.CLIENT_WHAT);
Bundle data = new Bundle();
data.putString("msg","hello,this is client");
msg.setData(data);
//指定当前消息是那个Messenger对象发送的,该对象就是我们在服务端
//向客户端发送Message的Messenger对象
msg.replyTo = mGetReplyMessenger;
try{
mService.send(msg);
}catch (RemoteException e){
e.printStackTrace();
}
}
@Override
public void onServiceDisconnected(ComponentName name) {
}
//客户端的Messenger对象
private Messenger mGetReplyMessenger = new Messenger(new Handler(Looper.getMainLooper(),this));
//处理服务端发送回来的Message
@Override
public boolean handleMessage(@NonNull Message msg) {
if(msg.what == MessengerService.SERVER_WHAT){
Log.d("client", "收到来自服务端的消息:" + msg.getData().getString("reply"));
}
return false;
}
@Override
protected void onDestroy() {
super.onDestroy();
if(mService != null && mService.getBinder().isBinderAlive()){
unbindService(this);
}
}
}
客户端输出:
服务端输出:
注意:由于MessengerService是在不同的线程,需要切换进程才能看到对于的日志输出
Messenger是通过Handler来实现消息发送的,而Handler的内部是通过消息队列来维护每一个Message对象,
队列是一个先进先出的数据结构,所以Messenger无法并发处理多个消息,只能一条一条的处理.
2.绑定其他应用的Service
上述代码是客户端和服务端都在同一个应用之内的两个不同进程,如果要绑定其他应用的xxx服务,需要通过显式Intent来绑定,
并且远程Service要设置 exported = "true",不然会抛异常
<service android:name=".MessengerServer" android:exported="true"/>
a.setClassName()方式
intent.setClassName("包名","包名.Service名称");
b.setComponent() 方式
intent.setComponent(new ComponentName("包名","包名.Service名称"));
例如:
Intent intent = new Intent();
intent.setComponent(new ComponentName("komine.demos.messenegerserver","komine.demos.messenegerserver.MessengerServer"));
//网上有说直接在bindService()之前调用startService()开启服务,我试过是无效的,小米Note4x(7.1)可以
//在调用该方法之前,需要在另一端(要绑定的服务所在的应用)开启对应的Service
//测试环境:模拟器和真机(索尼),Android11必要在对应应用开启Service才能绑定成功
bindService(intent, this, Context.BIND_AUTO_CREATE);
注意:在调用bindService()之前,需要远程进程(指要绑定的服务所在的应用)开启要绑定的Service,
不然bindService()不报错,也不会回调onServiceConnected()
三、AIDL
AIDL是Android 接口定义语言,可以通过AIDL在两个进程之间进行IPC通信.
1.基本使用
新建Game.java
public class Game implements Parcelable {
public String name;
public Game(String name){
this.name = name;
}
protected Game(Parcel in) {
name = in.readString();
}
public static final Creator<Game> CREATOR = new Creator<Game>() {
@Override
public Game createFromParcel(Parcel in) {
return new Game(in);
}
@Override
public Game[] newArray(int size) {
return new Game[size];
}
};
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(name);
}
}
新建Game.aidl
可能会提示名称不唯一的错误,不让创建,可以先随便取个名字,然后再重命名,应该是as的bug
Game.aidl 对应 Game.java
// Game.aidl
package komine.demos.ipcdemo3;
// Declare any non-default types here with import statements
//指向Game.java
parcelable Game;
新建IGameShopManager.aidl
// IGameShopManager.aidl
package komine.demos.ipcdemo3;
// Declare any non-default types here with import statements
//引入Game.aild 即使是在同一包名下也需要import
import komine.demos.ipcdemo3.Game;
import komine.demos.ipcdemo3.IDownloadCompleteListener;
interface IGameShopManager {
boolean buy(float money);
void download(in IDownloadCompleteListener listener);
void registerDownloadListener(in IDownloadCompleteListener listener);
void unregisterDownloadListener(in IDownloadCompleteListener listener);
}
新建IDownloadCompleteListener.aidl
// IDownloadCompleteListener.aidl
package komine.demos.ipcdemo3;
// Declare any non-default types here with import statements
import komine.demos.ipcdemo3.Game;
interface IDownloadCompleteListener {
void onDownloadCompleted(in Game game);
}
新建EShopManagerService.java
public class EShopManagerService extends Service {
//Android提供的用于跨进程删除listener的接口,内部维护了一个Map集合,key是IBinder,通过
//比对key来删除对应的listener,如果不使用这个类,而使用普通的集合,在服务解绑,页面关闭之后,listener也不会
//移除,可以在循环中不断回调打印日志试试
private RemoteCallbackList<IDownloadCompleteListener> listeners = new RemoteCallbackList<>();
private Binder mBinder = new IGameShopManager.Stub() {
@Override
public boolean buy(float money) throws RemoteException {
return money >= 100;
}
@Override
public void download(IDownloadCompleteListener listener) throws RemoteException {
Game game = new Game("黑暗之魂重置版");
try {
//模拟耗时操作
Thread.sleep(3000);
//固定写法,从RemoteCallbackList取数据的固定写法
listeners.beginBroadcast();
int size = listeners.getRegisteredCallbackCount();
for (int i = 0;i < size;i++){
//Android26+可以使用getRegisteredCallbackItem()方法直接获取
listeners.getBroadcastItem(i).onDownloadCompleted(game);
}
//固定写法
listeners.finishBroadcast();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
@Override
public void registerDownloadListener(IDownloadCompleteListener listener) throws RemoteException {
//注册回调接口
listeners.register(listener);
}
@Override
public void unregisterDownloadListener(IDownloadCompleteListener listener) throws RemoteException {
//移除回调接口
listeners.unregister(listener);
}
};
@Nullable
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
}
注册EShopManagerService
<service android:name=".EShopManagerService" android:process=":remote"/>
MainActivity.java
public class MainActivity extends AppCompatActivity implements ServiceConnection {
private IGameShopManager mShopManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bindService(new Intent(this,EShopManagerService.class),this, Context.BIND_AUTO_CREATE);
}
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
mShopManager = IGameShopManager.Stub.asInterface(service);
try {
//注册回调接口
mShopManager.registerDownloadListener(downloadCompleteListener);
} catch (RemoteException e) {
e.printStackTrace();
}
}
@Override
public void onServiceDisconnected(ComponentName name) {
}
public void buy(View view) throws RemoteException {
boolean buyResult = mShopManager.buy(100);
if(buyResult){
Toast.makeText(getApplicationContext(),"购买成功!",Toast.LENGTH_SHORT).show();
}
}
public void download(View view) {
try{
mShopManager.download(downloadCompleteListener);
}catch (Exception e){
e.printStackTrace();
}
}
private IDownloadCompleteListener downloadCompleteListener = new IDownloadCompleteListener.Stub() {
@Override
public void onDownloadCompleted(final Game game) throws RemoteException {
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),"下载完成:" + game.name,Toast.LENGTH_SHORT).show();
}
});
}
};
@Override
protected void onDestroy() {
super.onDestroy();
//如果mShopManager的Binder未被销毁
if(mShopManager != null && mShopManager.asBinder().isBinderAlive()){
unbindService(this);
try {
mShopManager.unregisterDownloadListener(downloadCompleteListener);
} catch (RemoteException e) {
e.printStackTrace();
}
}
}
}
---------------------------------2022-04-09 更新----------------------------------
2.AIDL绑定远程服务
绑定过程跟Messenger绑定远程服务是一致的.
首先将前面生成好的aidl文件夹全部拷贝到另一个app(服务端)中,直接复制main/aidl文件夹,粘贴就好了
注意:客户端的aidl 文件夹的包名要和服务端的aidl包名一致,复制后会报错,需要build生成所需的文件.
然后将之前创建的EShopManagerService.java复制到app下的(服务端)MainActivity同级目录下,
在AndroidManifest.xml中注册服务
<service android:name=".EShopManagerService" android:exported="true"/>
然后通过显式Intent绑定到远程Service
客户端绑定服务端Service
Intent intent = new Intent();
intent.setComponent(new ComponentName("包名(应用的包名)","(Service所在文件的包名).服务名称"));
bindService(intent,this, Context.BIND_AUTO_CREATE);
由于是复制粘贴的,包名有可能填错,最不会出错的办法是直接去Service文件的最上方复制package后面的包名
3.AIDL权限验证
默认情况下,我们创建的服务任何人都能绑定,只要知道包名和服务的名称就可以连接,
那么如何添加权限验证呢
3.1 在Service的onBind()方法中验证,只要return null,验证失败的客户端就无法绑定服务
@Nullable
@Override
public IBinder onBind(Intent intent) {
Boolean noAuthorized = true;
...
...
//至于验证方式有很多,比如在AndroidManifest.xml中自定义permission,然后判断是否有声明这个权限
//调用checkCallingOrSelfPermission()检查是否有权限
if(!noAuthorized){
return null;
}
return mBinder;
}
服务端AndroidManifest.xml
//申明一个连接到远程Service所需的自定义权限
<permission android:name="komine.demos.messenegerserver.EShopManagerService"/>
...
...
//在Service上指定android:permission:komine.demos.messenegerserver.EShopManagerService
<service android:name="komine.demos.ipcdemo3.EShopManagerService" android:exported="true" android:permission="komine.demos.messenegerserver.EShopManagerService"/>
客户端必须显式声明这个权限,不然会抛权限拒绝的异常
客户端AndroidManifest.xml
//komine.demos.messenegerserver.EShopManagerService 在服务端申明的自定义权限
<uses-permission android:name="komine.demos.messenegerserver.EShopManagerService"/>
3.2 在服务端的onTransact()验证
在Service中重写onTransact()方法,然后进行验证
private Binder mBinder = new IGameShopManager.Stub() {
...
...
@Override
public boolean onTransact(int code, Parcel data, Parcel reply, int flags) throws RemoteException {
//验证方式按自己需求进行选择,返回false表示验证失败
return super.onTransact(code, data, reply, flags);
}
四、ContentProvider
ContentProvider是Android中提供用于不同应用之间进行数据共享的方式.
1.基本使用
使用很简单,只需要新建一个类继承自ContentProvider即可
public class MyContentProvider extends ContentProvider {
private final static String TAG = "MyContentProvider";
@Override
public boolean onCreate() {
Log.d(TAG,"onCreate...");
return false;
}
@Nullable
@Override
public Cursor query(@NonNull Uri uri, @Nullable String[] projection, @Nullable String selection, @Nullable String[] selectionArgs, @Nullable String sortOrder) {
Log.d(TAG,"query " + Thread.currentThread().getName());
return null;
}
@Nullable
@Override
public String getType(@NonNull Uri uri) {
return "getType";
}
@Nullable
@Override
public Uri insert(@NonNull Uri uri, @Nullable ContentValues values) {
Log.d(TAG,"insert" + Thread.currentThread().getName());
return null;
}
@Override
public int delete(@NonNull Uri uri, @Nullable String selection, @Nullable String[] selectionArgs) {
Log.d(TAG,"delete" + Thread.currentThread().getName());
return 0;
}
@Override
public int update(@NonNull Uri uri, @Nullable ContentValues values, @Nullable String selection, @Nullable String[] selectionArgs) {
Log.d(TAG,"update" + Thread.currentThread().getName());
return 0;
}
}
然后在AndroidManifest.xml的application标签下注册
<provider
android:authorities="komine.demos.ipcdemo4.provider"
android:exported="true"
android:name=".MyContentProvider"/>
接下来就能在其他应用中访问
public class MainActivity extends AppCompatActivity{
private Messenger mService;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//authorities:其他应用的provider中定义的authorities值
//uri = content:// + authorities
Uri uri = Uri.parse("content://komine.demos.ipcdemo4.provider");
getContentResolver().query(uri,null,null,null,null);
getContentResolver().insert(uri,null);
getContentResolver().delete(uri,null,null);
getContentResolver().update(uri,null,null,null);
}
}
Android11+ 更改了应用之间交互的方式,需要在AndroidManifest.xml中添加queries标签,然后在其中添加目标应用的包名,才能访问到目标应用提供的ContentProvider.
放在manifest节点
<queries>
<package android:name="komine.demos.ipcdemo4" />
</queries>
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