【Service】bindService：绑定本地服务和远程服务示例[通俗易懂]

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发布于 2022-11-15 18:14:41

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发布于 2022-11-15 18:14:41

绑定本地服务

AndroidManifest.xml中声明服务：

        <service android:name=".TestLocalService">
            <intent-filter>
                <action android:name="maureen.intent.action.BIND_LOCAL_SERVICE"/>
            </intent-filter>
        </service>

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TestLocalService.java

public class TestLocalService extends Service {
    private final String TAG = TestLocalService.class.getSimpleName();
    private IBinder mServiceBinder = new TestLocalServiceBinder();

    public class TestLocalServiceBinder extends Binder {
            public TestLocalService getService() {
                return TestLocalService.this;
            }
    }

    public void testFunc() {
        Log.d(TAG,"testFunc");
        Log.d(TAG, Log.getStackTraceString(new Throwable()));
    }

    @Override
    public void onCreate() {
        super.onCreate();
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        Log.d(TAG, "onBind:mServiceBinder=" + mServiceBinder);
        return mServiceBinder;
    }

    @Override
    public boolean onUnbind(Intent intent) {
        return super.onUnbind(intent);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
    }
}

TestBindServiceActivity.java

点击按钮绑定service
绑定成功后调用TestLocalService里的testFunc方法
点击back键解绑服务

public class TestBindServiceActivity extends Activity {
    private static final String TAG = TestBindServiceActivity.class.getSimpleName();
    private static final String ACTION_BIND_LOCAL_SERVICE = "maureen.intent.action.BIND_LOCAL_SERVICE";
    private Button mBindLocalServiceBtn;
    private static ServiceConnection mLocalConnection;
    private static TestLocalService mLocalService = null;

    private static class TestLocalConenction implements ServiceConnection {
        @Override
        public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
            Log.d(TAG,"onServiceConnected:iBinder=" + iBinder);
            mLocalService = ((TestLocalService.TestLocalServiceBinder)iBinder).getService();
            mLocalService.testFunc();
        }

        @Override
        public void onServiceDisconnected(ComponentName componentName) {
            mLocalService = null;
        }
    }

    private static class ButtonClickListener implements View.OnClickListener {
        private WeakReference<TestBindServiceActivity> mActivity;
        public ButtonClickListener(TestBindServiceActivity activity) {
            mActivity = new WeakReference<>(activity);
        }
        @Override
        public void onClick(View view) {
            switch (view.getId()) {
                case R.id.bind_local_service:
                    Intent localIntent = new Intent();
                    //Without this, throw exception.
                    localIntent.setPackage("com.example.maureen.mytestbindservice");
                    localIntent.setAction(ACTION_BIND_LOCAL_SERVICE);
                    mActivity.get().bindService(localIntent, mLocalConnection, BIND_AUTO_CREATE);
                    break;
                default:
                    break;
            }
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.d(TAG, "onCreate");
        setContentView(R.layout.activity_test_bind_service);
        mLocalConnection = new TestLocalConenction();
        mBindLocalServiceBtn = findViewById(R.id.bind_local_service);
        mBindLocalServiceBtn.setOnClickListener(new ButtonClickListener(this));
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.d(TAG, "onDestroy");
        unbindService(mLocalConnection);
    }
}

值得注意的是，在TestLocalService中onBind函数返回的mBinder和TestBindServiceActivity中onServiceConnected中的参数iBinder是相同的：

onBind:mServiceBinder=com.example.maureen.mytestbindservice.TestLocalService$TestLocalServiceBinder@3ef6efd

onServiceConnected:iBinder=com.example.maureen.mytestbindservice.TestLocalService$TestLocalServiceBinder@3ef6efd

从Activity中调用testFunc并未通过Binder调用：

2010-01-02 04:29:32.944 5947-5947/com.example.maureen.mytestbindservice D/TestLocalService: testFunc
2010-01-02 04:29:32.950 5947-5947/com.example.maureen.mytestbindservice D/TestLocalService: java.lang.Throwable
        at com.example.maureen.mytestbindservice.TestLocalService.testFunc(TestLocalService.java:22)
        at com.example.maureen.mytestbindservice.TestBindServiceActivity$TestLocalConenction.onServiceConnected(TestBindServiceActivity.java:27)
        at android.app.LoadedApk$ServiceDispatcher.doConnected(LoadedApk.java:1652)
        at android.app.LoadedApk$ServiceDispatcher$RunConnection.run(LoadedApk.java:1681)
        at android.os.Handler.handleCallback(Handler.java:790)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6523)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:940)

绑定远程服务

AndroidManifest.xml中声明service，指定service运行的进程：

        <service android:name=".TestRemoteService"
                 android:process=":remote">
            <intent-filter>
                <action android:name="maureen.intent.action.BIND_REMOTE_SERVICE"/>
            </intent-filter>
        </service>

编写AIDL文件- IRemoteServiceAidlInterface.aidl

interface IRemoteServiceAidlInterface {
    /**
     * Demonstrates some basic types that you can use as parameters
     * and return values in AIDL.
     */
    void testFunc1();
    void testFunc2();
}

生成的对应的java文件-IRemoteServiceAidlInterface.java

public interface IRemoteServiceAidlInterface extends android.os.IInterface {
/** Local-side IPC implementation stub class. */
public static abstract class Stub extends android.os.Binder implements com.example.maureen.mytestbindservice.IRemoteServiceAidlInterface {
private static final java.lang.String DESCRIPTOR = "com.example.maureen.mytestbindservice.IRemoteServiceAidlInterface";
/** Construct the stub at attach it to the interface. */
public Stub() {
this.attachInterface(this, DESCRIPTOR);
}
/**
* Cast an IBinder object into an com.example.maureen.mytestbindservice.IRemoteServiceAidlInterface interface,
* generating a proxy if needed.
*/
public static com.example.maureen.mytestbindservice.IRemoteServiceAidlInterface asInterface(android.os.IBinder obj) {
if ((obj==null)) {
return null;
}
ndroid.os.IInterface iin = obj.queryLocalInterface(DESCRIPTOR);
if (((iin!=null)&&(iin instanceof com.example.maureen.mytestbindservice.IRemoteServiceAidlInterface))) {
return ((com.example.maureen.mytestbindservice.IRemoteServiceAidlInterface)iin);
}
return new com.example.maureen.mytestbindservice.IRemoteServiceAidlInterface.Stub.Proxy(obj);
}
@Override 
public android.os.IBinder asBinder() {
return this;
}
@Override 
public boolean onTransact(int code, android.os.Parcel data, android.os.Parcel reply, int flags) throws android.os.RemoteException {
java.lang.String descriptor = DESCRIPTOR;
switch (code) {
case INTERFACE_TRANSACTION: {
reply.writeString(descriptor);
return true;
}
case TRANSACTION_testFunc1: {
data.enforceInterface(descriptor);
this.testFunc1();
reply.writeNoException();
return true;
}
case TRANSACTION_testFunc2: {
data.enforceInterface(descriptor);
this.testFunc2();
reply.writeNoException();
return true;
}
default: {
return super.onTransact(code, data, reply, flags);
}
}
}
private static class Proxy implements com.example.maureen.mytestbindservice.IRemoteServiceAidlInterface {
private android.os.IBinder mRemote;
Proxy(android.os.IBinder remote) {
mRemote = remote;
}
@Override 
public android.os.IBinder asBinder() {
return mRemote;
}
public java.lang.String getInterfaceDescriptor() {
return DESCRIPTOR;
}
/**
* Demonstrates some basic types that you can use as parameters
* and return values in AIDL.
*/
@Override 
public void testFunc1() throws android.os.RemoteException {
android.os.Parcel _data = android.os.Parcel.obtain();
android.os.Parcel _reply = android.os.Parcel.obtain();
try {
_data.writeInterfaceToken(DESCRIPTOR);
mRemote.transact(Stub.TRANSACTION_testFunc1, _data, _reply, 0);
_reply.readException();
} finally {
_reply.recycle();
_data.recycle();
}
}
@Override 
public void testFunc2() throws android.os.RemoteException {
android.os.Parcel _data = android.os.Parcel.obtain();
android.os.Parcel _reply = android.os.Parcel.obtain();
try {
_data.writeInterfaceToken(DESCRIPTOR);
mRemote.transact(Stub.TRANSACTION_testFunc2, _data, _reply, 0);
_reply.readException();
} finally {
_reply.recycle();
_data.recycle();
}
}
}
static final int TRANSACTION_testFunc1 = (android.os.IBinder.FIRST_CALL_TRANSACTION + 0);
static final int TRANSACTION_testFunc2 = (android.os.IBinder.FIRST_CALL_TRANSACTION + 1);
}
/**
* Demonstrates some basic types that you can use as parameters
* and return values in AIDL.
*/
public void testFunc1() throws android.os.RemoteException;
public void testFunc2() throws android.os.RemoteException;
}

TestRemoteService.java

public class TestRemoteService extends Service {
private final String TAG= TestRemoteService.class.getSimpleName();
private IBinder mRemoteBinder = new RemoteServiceImpl(this);
private static class RemoteServiceImpl extends IRemoteServiceAidlInterface.Stub {
private final String TAG= RemoteServiceImpl.class.getSimpleName();
private WeakReference<TestRemoteService> mRemoteService;
public RemoteServiceImpl(TestRemoteService service) {
mRemoteService = new WeakReference<>(service);
}
@Override
public void testFunc1() {
Log.d(TAG,"testFunc1");
Log.d(TAG,Log.getStackTraceString(new Throwable()));
mRemoteService.get().testMyFunc1();
}
@Override
public void testFunc2() {
Log.d(TAG,"testFunc2");
mRemoteService.get().testMyFunc2();
}
}
private void testMyFunc1() {
Log.d(TAG,"testMyFunc1");
Log.d(TAG,Log.getStackTraceString(new Throwable()));
}
private void testMyFunc2() {
Log.d(TAG,"testMyFunc2");
}
@Override
public void onCreate() {
super.onCreate();
Log.d(TAG,"onCreate");
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
Log.d(TAG,"onBind:mRemoteBinder=" + mRemoteBinder);
return mRemoteBinder;
}
@Override
public boolean onUnbind(Intent intent) {
Log.d(TAG,"onUnbind");
return super.onUnbind(intent);
}
@Override
public void onDestroy() {
super.onDestroy();
Log.d(TAG,"onDestroy");
}
}

TestBindServiceActivity.java

① 点击按钮，绑定远程服务

②服务绑定成功后，调用aidl中声明的方法testFunc1和testFunc2

③点击back键，解绑服务

package com.example.maureen.mytestbindservice;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import java.lang.ref.WeakReference;
public class TestBindServiceActivity extends Activity {
private static final String TAG = TestBindServiceActivity.class.getSimpleName();
private static final String ACTION_BIND_REMOTE_SERVICE = "maureen.intent.action.BIND_REMOTE_SERVICE";
private Button mBindRemoteServiceBtn;
private static ServiceConnection mRemoteConnection;
private static class TestRemoteConection implements ServiceConnection {
@Override
public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
Log.d(TAG,"onServiceConnected:iBinder=" + iBinder);
IRemoteServiceAidlInterface remoteService = IRemoteServiceAidlInterface.Stub.asInterface(iBinder);
try {
remoteService.testFunc1();
remoteService.testFunc2();
} catch (RemoteException e) {
e.printStackTrace();
}
}
@Override
public void onServiceDisconnected(ComponentName componentName) {
}
}
private static class ButtonClickListener implements View.OnClickListener {
private WeakReference<TestBindServiceActivity> mActivity;
public ButtonClickListener(TestBindServiceActivity activity) {
mActivity = new WeakReference<>(activity);
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.bind_remote_service:
Intent remoteIntent = new Intent();
//Without this, throw exception.
remoteIntent.setPackage("com.example.maureen.mytestbindservice");
remoteIntent.setAction(ACTION_BIND_REMOTE_SERVICE);
mActivity.get().bindService(remoteIntent, mRemoteConnection, BIND_AUTO_CREATE);
break;
default:
break;
}
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "onCreate");
setContentView(R.layout.activity_test_bind_service);
mRemoteConnection = new TestRemoteConection();
mBindRemoteServiceBtn = findViewById(R.id.bind_remote_service);
mBindRemoteServiceBtn.setOnClickListener(new ButtonClickListener(this));
}
@Override
protected void onDestroy() {
super.onDestroy();
Log.d(TAG, "onDestroy");
unbindService(mRemoteConnection);
}
}

值得注意的是TestRemoteService.java的onBind函数中返回的mRemoteBinder是一个Binder服务端对象，即RemoteServiceImpl对象：

nBind:mRemoteBinder=com.example.maureen.mytestbindservice.TestRemoteService$RemoteServiceImpl@3920201

而在TestBindServiceActivity的TestRemoteServiceConnection的onServiceConnected函数中iBinder是Binder代理端：

onServiceConnected:iBinder=android.os.BinderProxy@6ff13d8

即Activity调用到TestRemoteService是通过Binder调用完成的。

例如TestRemoteService.RemoteServiceImpl.testFunc1调用堆栈：

2010-01-02 05:05:47.136 6482-6495/com.example.maureen.mytestbindservice:remote D/RemoteServiceImpl: testFunc1
2010-01-02 05:05:47.140 6482-6495/com.example.maureen.mytestbindservice:remote D/RemoteServiceImpl: java.lang.Throwable
at com.example.maureen.mytestbindservice.TestRemoteService$RemoteServiceImpl.testFunc1(TestRemoteService.java:24)
at com.example.maureen.mytestbindservice.IRemoteServiceAidlInterface$Stub.onTransact(IRemoteServiceAidlInterface.java:51)
at android.os.Binder.execTransact(Binder.java:697)

而TestRemoteService.testFunc1调用堆栈：

2010-01-02 05:05:47.140 6482-6495/com.example.maureen.mytestbindservice:remote D/TestRemoteService: testMyFunc1
2010-01-02 05:05:47.143 6482-6495/com.example.maureen.mytestbindservice:remote D/TestRemoteService: java.lang.Throwable
at com.example.maureen.mytestbindservice.TestRemoteService.testMyFunc1(TestRemoteService.java:37)
at com.example.maureen.mytestbindservice.TestRemoteService.access$000(TestRemoteService.java:11)
at com.example.maureen.mytestbindservice.TestRemoteService$RemoteServiceImpl.testFunc1(TestRemoteService.java:25)
at com.example.maureen.mytestbindservice.IRemoteServiceAidlInterface$Stub.onTransact(IRemoteServiceAidlInterface.java:51)
at android.os.Binder.execTransact(Binder.java:697)