Android通过继承Binder类实现多进程通信

private static final java.lang.String DESCRIPTOR = "org.ninetripods.mq.multiprocess_sever.IAidlCallBack";
private static final int KEY_FLAG = 0x110;

private class MyBinder extends Binder {
    /**
     * @param code 唯一标识，客户端传递标识执行服务端代码
     * @param data 客户端传递过来的参数
     * @param reply 服务器返回回去的值
     * @param flags 是否有返回值 0:有 1:没有
     * @return
     * @throws RemoteException 异常
     */
    @Override
    protected boolean onTransact(int code, Parcel data, Parcel reply, int flags) throws RemoteException {
      switch (code) {
        case KEY_FLAG:
          //标识服务器名称
          data.enforceInterface(DESCRIPTOR);
          Apple apple = new Apple("红星苹果", 15f, getString(R.string.response_binder_info));
          reply.writeNoException();
          reply.writeInt(1);
          apple.writeToParcel(reply, android.os.Parcelable.PARCELABLE_WRITE_RETURN_VALUE);
          return true;
      }

      return super.onTransact(code, data, reply, flags);
    }
  }

  @Override
  public IBinder onBind(Intent intent) {
    return new MyBinder();
  }

 <service
  android:name=".BinderService"
  android:enabled="true"
  android:exported="true">
  <intent-filter>
    <action android:name="android.mq.binder.service" />
    <category android:name="android.intent.category.DEFAULT" />
  </intent-filter>
</service>

private ServiceConnection binderConnection = new ServiceConnection() {
    @Override
    public void onServiceConnected(ComponentName name, IBinder service) {
      isBound = true;
      mService = service;
      if (mService != null) {
        //声明两个Parcel类型数据(_data和_reply) 一个用于传输数据 一个用于接收数据
        android.os.Parcel _data = android.os.Parcel.obtain();
        android.os.Parcel _reply = android.os.Parcel.obtain();
        Apple apple;
        try {
          //与服务器端的enforceInterface(DESCRIPTOR)对应
          _data.writeInterfaceToken(DESCRIPTOR);
          //调用服务端的transact()传输数据
          mService.transact(KEY_FLAG, _data, _reply, 0);
          _reply.readException();
          if (0 != _reply.readInt()) {
            //接收服务端响应数据
            apple = Apple.CREATOR.createFromParcel(_reply);
          } else {
            apple = null;
          }
          showMessage(apple != null ? ("\n" + apple.getNoticeInfo() + "\n名称："
              + apple.getName() + "\n价格：" + apple.getPrice() + " 元") : "未获得服务器信息", R.color.red_f);
        } catch (Exception e) {
          e.printStackTrace();
        } finally {
          _data.recycle();
          _reply.recycle();
        }
      }
    }

    @Override
    public void onServiceDisconnected(ComponentName name) {
      isBound = false;
      mService = null;
    }
  };

 Intent intent = new Intent();
 intent.setAction("android.mq.binder.service");
 intent.setPackage("org.ninetripods.mq.multiprocess_sever");
 bindService(intent, binderConnection, BIND_AUTO_CREATE);