android aidl机制 Android中怎样利用AIDL机制调用远程服务
水火379 人气:0想了解Android中怎样利用AIDL机制调用远程服务的相关内容吗,水火379在本文为您仔细讲解android aidl机制的相关知识和一些Code实例,欢迎阅读和指正,我们先划重点:android_aidl机制,aidl远程调用,下面大家一起来学习吧。
在Android中,每个应用程序都有自己的进程,当需要在不同的进程之间传递对象时,该如何实现呢?显然, Java中是不支持跨进程内存共享的。因此要传递对象,需要把对象解析成操作系统能够理解的数据格式,以达到跨界对象访问的目的。在JavaEE中,采用RMI通过序列化传递对象。在Android中,则采用AIDL(Android Interface DefinitionLanguage:接口描述语言)方式实现。
AIDL是一种接口定义语言,用于约束两个进程间的通讯规则,供编译器生成代码,实现Android设备上的两个进程间通信(IPC)。AIDL的IPC机制和EJB所采用的CORBA很类似,进程之间的通信信息,首先会被转换成AIDL协议消息,然后发送给对方,对方收到AIDL协议消息后再转换成相应的对象。由于进程之间的通信信息需要双向转换,所以android采用代理类在背后实现了信息的双向转换,代理类由android编译器生成,对开发人员来说是透明的。
服务端:
//CalculateInterface.aidl package com.itheima.aidl.calculate; interface CalculateInterface { double doCalculate(double a, double b); } //CalculateService.java package com.itheima.myaidl.server; import com.itheima.aidl.calculate.CalculateInterface; import android.app.Service; import android.content.Intent; import android.os.IBinder; import android.os.RemoteException; import android.util.Log; public class CalculateService extends Service{ private final CalculateInterface.Stub mBinder = new CalculateInterface.Stub() { @Override public double doCalculate(double a, double b) throws RemoteException { return a+b; } }; @Override public IBinder onBind(Intent intent) { Log.i("test","onBind..."); return mBinder; } @Override public boolean onUnbind(Intent intent) { Log.i("test","onUnbind..."); return super.onUnbind(intent); } @Override public void onCreate() { super.onCreate(); Log.i("test","onCreate..."); } @Override public void onDestroy() { super.onDestroy(); Log.i("test","onDestroy..."); } } //服务端manifast文件 <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.itheima.myaidl.server" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="14" android:targetSdkVersion="19" /> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="com.itheima.myaidl.server.MainActivity" android:configChanges="locale|layoutDirection" android:theme="@android:style/Theme.Light.NoTitleBar" android:screenOrientation="portrait"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <service android:name="com.itheima.myaidl.server.CalculateService"> <intent-filter> <action android:name="com.itheima.myaidl.server.CalculateService" /> </intent-filter> </service> </application> </manifest> //客户端 //MainActivity.java package com.itheima.myaidl.client; import android.app.Activity; import android.content.ComponentName; import android.content.Context; 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 com.itheima.aidl.calculate.CalculateInterface; public class MainActivity extends Activity { private CalculateInterface mService; private ServiceConnection mServiceConnection = new ServiceConnection() { @Override public void onServiceDisconnected(ComponentName name) { Log.i("test","service disconnected..."); mService = null; } @Override public void onServiceConnected(ComponentName name, IBinder service) { Log.i("test","service connected..."); mService = CalculateInterface.Stub.asInterface(service); //获取接口实例 } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //绑定远程服务 Bundle bundle = new Bundle(); Intent intent = new Intent(); intent.putExtras(bundle); intent.setAction("com.itheima.myaidl.server.CalculateService"); bindService(intent, mServiceConnection, Context.BIND_AUTO_CREATE); } //TODO activity加载完毕时回调此方法 @Override public void onWindowFocusChanged(boolean hasFocus) { if(hasFocus){ try{ double result = mService.doCalculate(1, 2); Log.i("test","result===>"+result); }catch(RemoteException e){ e.printStackTrace(); } } super.onWindowFocusChanged(hasFocus); } @Override protected void onDestroy() { unbindService(mServiceConnection); //解绑远程服务 super.onDestroy(); } }
运行结果截图:
以上所述是小编给大家介绍的Android中如何利用AIDL机制调用远程服务的相关知识,希望对大家有所帮助!
加载全部内容