先来两个传送门:
http://www.cnblogs.com/yydcdut/p/3961545.html Android面试,与Service交互方式
http://www.cnblogs.com/yydcdut/p/3810816.html Android -- Service绑定解绑和aidl
Build-->Make Project,生成相应的java文件。
先看看aidl文件
// ICameraData.aidl package com.yydcdut.cameramvc; // Declare any non-default types here with import statements interface ICameraData { void add(String fileName,int size, long time); }
生成的aidl文件:
/* * This file is auto-generated. DO NOT MODIFY. * Original file: /Users/yuyidong/AndroidStudioProjects/Camera-Camera2-MVC/app/src/main/aidl/com/yydcdut/cameramvc/ICameraData.aidl */ package com.yydcdut.cameramvc; // Declare any non-default types here with import statements public interface ICameraData extends android.os.IInterface { /** * Local-side IPC implementation stub class. */ public static abstract class Stub extends android.os.Binder implements com.yydcdut.cameramvc.ICameraData { private static final java.lang.String DESCRIPTOR = "com.yydcdut.cameramvc.ICameraData"; /** * Construct the stub at attach it to the interface. */ public Stub() { this.attachInterface(this, DESCRIPTOR); } /** * Cast an IBinder object into an com.yydcdut.cameramvc.ICameraData interface, * generating a proxy if needed. */ public static com.yydcdut.cameramvc.ICameraData asInterface(android.os.IBinder obj) { if ((obj == null)) { return null; } android.os.IInterface iin = obj.queryLocalInterface(DESCRIPTOR);//根据包名获取本地实现的一个接口的实例,如果是本地service则可以获取到 if (((iin != null) && (iin instanceof com.yydcdut.cameramvc.ICameraData))) { return ((com.yydcdut.cameramvc.ICameraData) iin);////如果得到的实例是ICameraData的对象,则返回 } return new com.yydcdut.cameramvc.ICameraData.Stub.Proxy(obj);//如果无法得到本地实现的对象则会返回一个代理对象 } @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 { switch (code) { case INTERFACE_TRANSACTION: { reply.writeString(DESCRIPTOR); return true; } case TRANSACTION_add: { data.enforceInterface(DESCRIPTOR); java.lang.String _arg0; _arg0 = data.readString();//读取fileName int _arg1; _arg1 = data.readInt();//读取size long _arg2; _arg2 = data.readLong();//读取time this.add(_arg0, _arg1, _arg2); reply.writeNoException(); return true; } } return super.onTransact(code, data, reply, flags); } private static class Proxy implements com.yydcdut.cameramvc.ICameraData { 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; } @Override public void add(java.lang.String fileName, int size, long time) throws android.os.RemoteException { android.os.Parcel _data = android.os.Parcel.obtain(); android.os.Parcel _reply = android.os.Parcel.obtain(); try { _data.writeInterfaceToken(DESCRIPTOR); _data.writeString(fileName);//写入 _data.writeInt(size);//写入 _data.writeLong(time);//写入 mRemote.transact(Stub.TRANSACTION_add, _data, _reply, 0);//调用binderDriver的提供的方法将参数发给服务端 _reply.readException(); } finally { _reply.recycle(); _data.recycle(); } } } static final int TRANSACTION_add = (android.os.IBinder.FIRST_CALL_TRANSACTION + 0); } public void add(java.lang.String fileName, int size, long time) throws android.os.RemoteException; }
代理中也实现了ICameraData接口定义的方法,我们以add方法为例,里面将参数打包发送给Server端。在Server端收到请求后,会调用service中我们实现的那个stub对象(mBinder)的onTransact方法。
ICameraData.Stub mStub = new ICameraData.Stub() { @Override public void add(String fileName, int size, long time) throws RemoteException { //............. }; @Override public IBinder onBind(Intent intent) { return mStub; }
private ServiceConnection mServiceConnection = new ServiceConnection() { @Override public void onServiceConnected(ComponentName name, IBinder service) { mCameraService = ICameraData.Stub.asInterface(service); mIsBind = true; } @Override public void onServiceDisconnected(ComponentName name) { mCameraService = null; mIsBind = false; } };
mCameraService.add(fileName, size, time);
<service android:name=".CameraService" android:process=":remote"></service>
android.os.TransactionTooLargeException
在Android中,进程间通信通过binder实现,bind是通信的数据载体,当序列化后的数据单元过大时,就会出问题,报出android.os.TransactionTooLargeException。官方文档里有说明,最大通常限制为1M.也就是说如果大于1M数据的话,就应该分开传。理论上说,应该都是对象和字符串类型的数据为主,只要不是大图片实体等问题,一般应该够用。