1. 使用Bundle
- 由于Bundle實(shí)現(xiàn)了Parcelable接口,所以在四大組件中的三大組件(Activity, Service, Receiver)都支持在Intent中傳遞Bundle.就可以在Bundle中附加我們需要的信息通過Intent發(fā)送出去. 當(dāng)然傳遞的類型必須是能夠被序列化的,
- 這個(gè)地方有一個(gè)疑問,intent也可以傳輸數(shù)據(jù)啊,為啥還要用bundle呢?
- 解釋是:bundle的內(nèi)部實(shí)現(xiàn)是一個(gè)hashMap.一個(gè)容器將要傳輸?shù)臄?shù)據(jù)裝起來然后做傳輸,如果使用intent則需要一個(gè)一個(gè)傳輸,如果此數(shù)據(jù)需要從A傳到B然后傳入C,那么用bundle就很方便了,而對(duì)于intent則還需要在B取出,然后在轉(zhuǎn)入..
- 由于Bundle使用很簡(jiǎn)單就不展示代碼了;
2. 使用文件共享
- 原理:兩個(gè)進(jìn)程通過讀/寫同一個(gè)文件來交換數(shù)據(jù). 例如進(jìn)程A把數(shù)據(jù)寫入文件中,而進(jìn)程B從文件中讀取出來數(shù)據(jù).
- 需要注意的點(diǎn):文件共享適合在對(duì)數(shù)據(jù)同步要求不高的進(jìn)程之間進(jìn)行通信,并且要妥善的處理并發(fā)讀寫的問題.
- SharePreferencess是Android提供的一個(gè)輕量級(jí)方案,通過鍵值對(duì)存儲(chǔ)數(shù)據(jù),底層采用XML文件來進(jìn)行存儲(chǔ). 存儲(chǔ)路徑/data/data/package name/shared_prefs目錄下. 也屬于文件的一種,但是由于系統(tǒng)對(duì)SP的讀寫存在一定的緩存策略,內(nèi)存中會(huì)有一份緩存,所以多進(jìn)程下,系統(tǒng)對(duì)它的讀寫也就變得不可靠.
- 文件共享,使用sp就是比較好的例子,sp的使用也比較簡(jiǎn)單就不列出了
3. 使用Messenger
Messenger(信使). 不同的進(jìn)程中可以傳遞Message對(duì)象, 在Message中放入我們需要傳遞的數(shù)據(jù),就可實(shí)現(xiàn)進(jìn)程間傳遞. Messenger是一種輕量級(jí)的IPC方案,它的底層實(shí)現(xiàn)AIDL.
-
具體實(shí)現(xiàn),共分為四部:
-
客戶端進(jìn)程創(chuàng)建兩個(gè) Messenger，一個(gè) Sender ，一個(gè) Receiver；
private Messenger mGetReplyMessenger = new Messenger(new Handler(){ @Override public void handleMessage(Message msg) { switch (msg.what){ case 0: Log.d(TAG, "handleMessage: 這里是客戶端:::"+msg.getData().getString("reply")); break; default: super.handleMessage(msg); } } }); private ServiceConnection mConnection = new ServiceConnection() { @Override public void onServiceConnected(ComponentName componentName, IBinder iBinder) { mMessenger = new Messenger(iBinder); Message message = Message.obtain(null, 1); Bundle bundle = new Bundle(); bundle.putString("msg","wo shi 客戶端"); message.setData(bundle); message.replyTo= mGetReplyMessenger; try { mMessenger.send(message); } catch (RemoteException e) { e.printStackTrace(); } } @Override public void onServiceDisconnected(ComponentName componentName) { } }; -
綁定服務(wù),由于在不同的應(yīng)用中所以采用隱士啟動(dòng)方式:
Intent intent = new Intent(); intent.setAction("com.lemon.service"); intent.setComponent(new ComponentName("com.lemon.messgagertest","com.lemon.messgagertest.MessagerService")); bindService(intent, mConnection,BIND_AUTO_CREATE);
注意:采用隱士啟動(dòng)的時(shí)候,需要設(shè)置 intent.setComponent(),不然會(huì)報(bào)錯(cuò),找不到;
-
服務(wù)端,接受信息,然后處理,然后返回:
private Messenger mMessenger = new Messenger(new Handler(){ @Override public void handleMessage(Message msg) { switch (msg.what){ case 1: Log.e(TAG,"receive msg from client "+msg.getData().getString("msg")); Messenger client = msg.replyTo; Message message = Message.obtain(null, 0); Bundle bundle = new Bundle(); bundle.putString("reply","消息已收到,稍后回復(fù)"); message.setData(bundle); try { client.send(message); } catch (RemoteException e) { e.printStackTrace(); } break; default: super.handleMessage(msg); } } }); -
配置xml文件:
<service android:name=".MessagerService" android:process=":remote"> <intent-filter> <action android:name="com.lemon.service"></action> </intent-filter> </service>
-
Messenger使用很簡(jiǎn)單,但是有局限性,因?yàn)镸essenger對(duì)AIDL進(jìn)行了封裝,使得在使用時(shí)更加簡(jiǎn)單,并且它的處理方式是一次處理一個(gè)請(qǐng)求,因此服務(wù)器端不用考慮線程同步因?yàn)榉?wù)端不存在并發(fā)執(zhí)行的情形.
在使用Messenger進(jìn)行數(shù)據(jù)傳遞必須將數(shù)據(jù)放入到Message中. 而Messenger和Message都實(shí)現(xiàn)了序列化接口. 所以可以在進(jìn)程間通信.
4. 使用AIDL
雖然Messenger使用方便, 但是要清楚它是以串行的方式處理客戶端發(fā)來的消息,如果有大量并發(fā)的請(qǐng)求. 或者需求是跨進(jìn)程調(diào)用服務(wù)端的方法時(shí). 就無法使用Messenger. 這個(gè)時(shí)候就該AIDL
-
對(duì)于使用AIDL的流程簡(jiǎn)單梳理一遍
- 服務(wù)端
- 服務(wù)端創(chuàng)建一個(gè)Service用來監(jiān)聽客戶端的連接請(qǐng)求, 然后創(chuàng)建一個(gè)AIDL文件,將暴露給客戶端的接口在這個(gè)AIDL文件中聲明,最后在Service中實(shí)現(xiàn)這個(gè)AIDL接口并在onBind()返回即可.
- 客戶端
- 綁定服務(wù)端的Service,綁定成功后,將服務(wù)端返回來的Binder對(duì)象轉(zhuǎn)成AIDL接口所屬的類型,接著就可以直接調(diào)用AIDL中的方法了.
- 服務(wù)端
-
具體的實(shí)現(xiàn)
-
AIDL 文件
Book.aidl
package com.lemon.bookaidl; parcelable Book;IBookManger.aidl
package com.lemon.bookaidl; // Declare any non-default types here with import statements import com.lemon.bookaidl.book; import com.lemon.bookaidl.IOnBookArrivedListener; interface IBookManger { List<Book> getBookList(); void addBook(in Book book); void registerListener(IOnBookArrivedListener listener); void unregisterListener(IOnBookArrivedListener listener); }IOnBookArrivedListener.aidl
package com.lemon.bookaidl; // Declare any non-default types here with import statements import com.lemon.bookaidl.book; interface IOnBookArrivedListener { void IOnBookArriverListener(in Book book); } -
服務(wù)端:
public class BookMangerService extends Service { private static final String TAG = "BookMangerService"; private AtomicBoolean mIsServiceDestoryed = new AtomicBoolean(false); private CopyOnWriteArrayList<Book> mBookList = new CopyOnWriteArrayList<Book>(); private RemoteCallbackList<IOnBookArrivedListener> mListeners = new RemoteCallbackList<>(); private Binder mBinder = new IBookManger.Stub() { @Override public List<Book> getBookList() throws RemoteException { return mBookList; } @Override public void addBook(Book book) throws RemoteException { mBookList.add(book); } @Override public void registerListener(IOnBookArrivedListener listener) throws RemoteException { mListeners.register(listener); } @Override public void unregisterListener(IOnBookArrivedListener listener) throws RemoteException { mListeners.unregister(listener); } }; @Nullable @Override public IBinder onBind(Intent intent) { return mBinder; } @Override public void onCreate() { super.onCreate(); mBookList.add(new Book(1,"Android")); mBookList.add(new Book(2, "Ios")); new Thread(new serviceWork()).start(); } private class serviceWork implements Runnable { @Override public void run() { while (!mIsServiceDestoryed.get()){ try { Thread.sleep(5000); } catch (InterruptedException e) { e.printStackTrace(); } int bookId = mBookList.size()+1; Book newBook = new Book(bookId,"#new Book"+bookId); try { onNewBookArrived(newBook); } catch (RemoteException e) { e.printStackTrace(); } } } } private void onNewBookArrived(Book newBook) throws RemoteException { mBookList.add(newBook); final int N = mListeners.beginBroadcast(); Log.e("onNewBookArrived","registener listener size:" + N); for (int i = 0 ;i<N ;i++){ IOnBookArrivedListener l = mListeners.getBroadcastItem(i); if (l!=null){ l.IOnBookArriverListener(newBook); } } mListeners.finishBroadcast(); } @Override public void onDestroy() { mIsServiceDestoryed.set(true); super.onDestroy(); } }
-
-
客戶端
public class MainActivity extends AppCompatActivity { private static final String TAG = "MainActivity"; private static final int MESSAGE_NEW_BOOK_ARRIVED = 1; private IBookManger mIBookManger; private android.os.Handler mHandler = new android.os.Handler(){ @Override public void handleMessage(Message msg) { switch (msg.what){ case MESSAGE_NEW_BOOK_ARRIVED: Log.e(TAG, "received new book:" + msg.obj); break; default: super.handleMessage(msg); } } }; private ServiceConnection mServiceConnection = new ServiceConnection() { @Override public void onServiceConnected(ComponentName componentName, IBinder iBinder) { mIBookManger = IBookManger.Stub.asInterface(iBinder); try { List<Book> bookList = mIBookManger.getBookList(); Log.e(TAG, "query book list,list type:" + bookList.getClass().getCanonicalName()); Log.e(TAG, "query book list:" + bookList.toString()); Book newBook = new Book(3, "android進(jìn)階"); mIBookManger.addBook(newBook); Log.e(TAG, "add book:" + newBook); List<Book> newList = mIBookManger.getBookList(); Log.e(TAG, "query book list:" + newList.toString()); mIBookManger.registerListener(mIOnBookArrivedListener); } catch (RemoteException e) { e.printStackTrace(); } } @Override public void onServiceDisconnected(ComponentName componentName) { } }; private IOnBookArrivedListener mIOnBookArrivedListener = new IOnBookArrivedListener.Stub() { @Override public void IOnBookArriverListener(Book book) throws RemoteException { mHandler.obtainMessage(MESSAGE_NEW_BOOK_ARRIVED,book).sendToTarget(); } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); bindService(); } private void bindService() { Intent intent = new Intent(); intent.setAction("com.lemon.bookservice"); intent.setComponent(new ComponentName("com.lemon.bookaidl","com.lemon.bookaidl.BookMangerService")); bindService(intent,mServiceConnection, Context.BIND_AUTO_CREATE); } @Override protected void onDestroy() { if (mIBookManger != null && mIBookManger.asBinder().isBinderAlive()){ Log.e(TAG, "unregister listener:" + mIOnBookArrivedListener); try { mIBookManger.unregisterListener(mIOnBookArrivedListener); } catch (RemoteException e) { e.printStackTrace(); } } unbindService(mServiceConnection); super.onDestroy(); } } -
幾個(gè)點(diǎn)得理解:
- CopyOnWriteArrayList:支持并發(fā)的讀寫，這里我們使用它來進(jìn)行自動(dòng)的線程同步;
- RemoteCallBackList:是系統(tǒng)專門提供的用于刪除跨進(jìn)程listener的接口:它的工作原理其實(shí)很簡(jiǎn)單：在它的內(nèi)部有一個(gè)Map結(jié)構(gòu)專門用來保存所有AIDL回調(diào)3. 這個(gè)例子涉及到的東西比較多,如果剛接觸可以參考點(diǎn)簡(jiǎn)單的例子,就實(shí)現(xiàn)個(gè)遠(yuǎn)程服務(wù)進(jìn)行計(jì)算,而client獲取到結(jié)果的這種,實(shí)現(xiàn)特別簡(jiǎn)單,主要看你怎么理解
5. 使用ContentProvider
- ContentProvider是Android提供專門用于不用應(yīng)用進(jìn)行數(shù)據(jù)共享的方式. 它的底層同樣也是Binder. 因?yàn)橄到y(tǒng)封裝, 所以它的使用比起AIDL要簡(jiǎn)單很多.
- 要實(shí)現(xiàn)一個(gè)內(nèi)容提供者, 只需要寫一個(gè)類繼承ContentProvider,并復(fù)寫六個(gè)抽象方法. 其中有四個(gè)是CURD操作方法. 一個(gè)onCreate()用來做初始化. 一個(gè)getType()用來返回一個(gè)Uri請(qǐng)求所對(duì)應(yīng)的MIME類型,比如圖片還是視頻等. 如果我們不關(guān)心那么可是直接返回NULL或者
6. 使用Socket
- Socket也稱為套接字. 是網(wǎng)絡(luò)通信中的概念, 它分為流式套接字和用戶數(shù)據(jù)包套接字兩種. 分別對(duì)應(yīng)于網(wǎng)絡(luò)的傳輸控制層中TCP和UDP協(xié)議.
socket實(shí)現(xiàn)IPC.png
客戶端:
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private static final String TAG="MainActivity";
private Button mSend;
private EditText mInput;
private TextView mMessage;
private Socket mClientSocket;
private PrintWriter mPrintWriter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
}
private void initView() {
mMessage = (TextView) findViewById(R.id.tv_message);
mInput = (EditText) findViewById(R.id.et_input);
mSend = (Button) findViewById(R.id.bt_send);
mSend.setOnClickListener(this);
Intent service = new Intent(this, SocketService.class);
startService(service);
new Thread(){
@Override
public void run() {
connectTCPserver();
}
}.start();
}
private void connectTCPserver() {
Socket socket=null;
while (socket==null) {
try {
socket = new Socket("localhost", 8888);
mClientSocket = socket;
mPrintWriter = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true);
} catch (IOException e) {
SystemClock.sleep(1000);
}
}
try {
BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
while (!isFinishing()){
String msg = br.readLine();
if (msg!=null){
String time = formateDateTime(System.currentTimeMillis());
Log.e(TAG,"客戶端收到信息:"+msg+" at:"+time);
}
}
mPrintWriter.close();
br.close();
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
private String formateDateTime(long l) {
return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date(l));
}
@Override
public void onClick(View view) {
if (view== mSend) {
final String msg = mInput.getText().toString();
if (!TextUtils.isEmpty(msg) && mPrintWriter != null) {
//像服務(wù)器發(fā)送信息
Log.e(TAG,"client has send '" + msg + "' at " + formateDateTime(System.currentTimeMillis()));
mPrintWriter.println(msg);
mInput.setText("");
}
}
}
@Override
protected void onDestroy() {
if (mClientSocket != null) {
try {
mClientSocket.shutdownInput();
mClientSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
super.onDestroy();
}
}
服務(wù)端:
public class SocketService extends Service {
private static final String TAG= "SocketService";
private boolean mIsSocketServiceDestory=false;
@Override
public void onCreate() {
new Thread(new TcpServer()).start();
super.onCreate();
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onDestroy() {
mIsSocketServiceDestory=true;
super.onDestroy();
}
private class TcpServer implements Runnable{
@Override
public void run() {
ServerSocket mServerSocket;
try {
mServerSocket = new ServerSocket(8888);
} catch (IOException e) {
e.printStackTrace();
return;
}
while (!mIsSocketServiceDestory){
try {
final Socket accept = mServerSocket.accept();
new Thread(new Runnable() {
@Override
public void run() {
try {
replyClient(accept);
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
private void replyClient(Socket accept) throws IOException {
BufferedReader input = new BufferedReader(new InputStreamReader(accept.getInputStream()));
PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(accept.getOutputStream())),true);
while (!mIsSocketServiceDestory){
String line = input.readLine();
if (line==null)break;
Log.e(TAG,"## reveive msg :"+line);
String message = "server has received your message:"+line;
out.println(message);
}
out.close();
input.close();
accept.close();
}
}
7. sharedUserId
sharedUserId的作用是讓兩個(gè)應(yīng)用程序共享一個(gè)user id，我們都知道Linux進(jìn)程給每一個(gè)應(yīng)用程序分配了一個(gè)獨(dú)立的user id，所以如果兩個(gè)或多個(gè)應(yīng)用程序的簽名相同并且設(shè)置了一樣的sharedUserId，他們將會(huì)共享一個(gè)user id，相同user id的應(yīng)用程序可以訪問對(duì)方的數(shù)據(jù)（也就是說如果應(yīng)用程序中的一個(gè)文件的權(quán)限是600，相同uid可以直接訪問，反之則無法訪問），并且設(shè)置成一個(gè)Android:process就能夠運(yùn)行在一個(gè)進(jìn)程中了。
- sharedUserId方式主要就是使用createPackageContext (String packageName, int flags)函數(shù)，該函數(shù)用來返回指定包名應(yīng)用的上下文，注意是application的context。
- 注意里面的兩個(gè)參數(shù),尤其是第二個(gè):這個(gè)flag，有CONTEXT_INCLUDE_CODE和CONTEXT_IGNORE_SECURITY兩個(gè)選項(xiàng),CONTEXT_INCLUDE_CODE的作用就是在調(diào)用者的進(jìn)程執(zhí)行該應(yīng)用的代碼,也就是說可以使用getClassLoader()函數(shù)來初始化該application的相關(guān)類,如果需要加載的application不能被安全的加載進(jìn)進(jìn)程的話，將會(huì)拋出一個(gè)SecurityException，如果這個(gè)標(biāo)示沒有被設(shè)置，那么將不會(huì)在被加載的類上面施加任何約束，getClassLoader()將會(huì)返回默認(rèn)的系統(tǒng)類加載器；CONTEXT_IGNORE_SECURITY的意思是忽略任何安全警告，和CONTEXT_INCLUDE_CODE標(biāo)識(shí)一起使用可能會(huì)將不安全的代碼加載進(jìn)進(jìn)程，所以謹(jǐn)慎使用。
1. 獲取client應(yīng)用的context
context=createPackageContext("com.lemon.shareuidclient",CONTEXT_INCLUDE_CODE|CONTEXT_IGNORE_SECURITY);
tv_context.setText(context.toString());
2. 獲取client應(yīng)用的drawable圖片
int id = context.getResources().getIdentifier("android_boot","drawable","com.lemon.shareuidclient");
iv_pic.setImageDrawable(ContextCompat.getDrawable(context,id));
3. 獲取client應(yīng)用的string中得值
int ie = context.getResources().getIdentifier("lemon","string","com.lemon.shareuidclient");
tv_string.setText(context.getString(ie));
4. 打開client應(yīng)用的activity
Intent intent = new Intent();
intent.setComponent(new ComponentName("com.lemon.shareuidclient","com.lemon.shareuidclient.MainActivity"));
startActivity(intent);
5. 調(diào)用client中得方法
try {
Class clazz = context.getClassLoader().loadClass("com.lemon.shareuidclient.Method");
Object instance = clazz.newInstance();
int [] arr= new int []{3,4,5,6};
int sum = (int) clazz.getMethod("add",int[].class).invoke(instance,arr);
tv_sum.setText(" sum: ="+sum);
} catch (Exception e) {
e.printStackTrace();
}
6. 獲得client中得sharepreference
SharedPreferences lemon = context.getSharedPreferences("lemon", MODE_MULTI_PROCESS);
String string = lemon.getString("adress", "china");
tv_shared_preference.setText(string );
由于SharedPreferences是有緩存機(jī)制的，所以如果在B應(yīng)用中修改了該SharedPreferences文件，接著A應(yīng)用去讀取該文件中修改的那個(gè)值，這時(shí)你會(huì)發(fā)現(xiàn)還是修改前的值，這就是緩存機(jī)制導(dǎo)致的問題，不過有一個(gè)flag可以解決這個(gè)問題：MODE_MULTI_PROCESS，但是非常不幸的是api23已經(jīng)將該標(biāo)識(shí)deprecated了，原因是在一些版本上不可靠，有興趣的可以去了解一下;
8.對(duì)比
image.png
