如何使用反射来更改备份服务？

Question

我发布了一个关于Android 5.1的新行为的问题,该行为在设备上设置设备所有者时会禁用备份服务...

一个可能的解决方案可能是(我猜)使用反射来解决问题:我可以在隐藏类中使用特定方法找到一些反射示例,但这种情况看起来更复杂,使用另一个隐藏类(ServiceManager)的构造函数我不知道如何做到这一点......

令我烦恼的代码位于第3739至3749行的DevicePolicyManagerService.java(可在此处找到):

long ident = Binder.clearCallingIdentity();
try {
    IBackupManager ibm = IBackupManager.Stub.asInterface(
        ServiceManager.getService(Context.BACKUP_SERVICE));
    ibm.setBackupServiceActive(UserHandle.USER_OWNER, false);
} catch (RemoteException e) {
    throw new IllegalStateException("Failed deactivating backup service.", e);
} finally {
    Binder.restoreCallingIdentity(ident);
}

我的目标是重新启用备份服务,理想情况下,这将调用类似于:

ibm.setBackupServiceActive(UserHandle.USER_OWNER, false);

你能帮帮我吗？

Answer 1

试试这个代码：

    try {
        Class<?> iBackupManagerClass = Class.forName("android.app.backup.IBackupManager");
        Class<?> serviceManagerClass = Class.forName("android.os.ServiceManager");
        Class<?>[] classes = iBackupManagerClass.getDeclaredClasses();
        Class<?> stubClass = null;
        for (Class clazz : classes) {
            if (clazz.getSimpleName().equals("Stub")) {
                stubClass = clazz;
            }
        }

        Method setBackupServiceActiveMethod = iBackupManagerClass.getMethod("setBackupServiceActive", int.class, boolean.class);
        Method asInterfaceMethod = stubClass.getMethod("asInterface", IBinder.class);
        Method getServiceMethod = serviceManagerClass.getMethod("getService", String.class);

        Object ibm = asInterfaceMethod.invoke(null, getServiceMethod.invoke(null, "backup"));
        setBackupServiceActiveMethod.invoke(ibm, 0, false);

    } catch (ClassNotFoundException e) {
        Log.e("TEST", e.getMessage(), e);
    } catch (NoSuchMethodException e) {
        Log.e("TEST", e.getMessage(), e);
    } catch (InvocationTargetException e) {
        Log.e("TEST", e.getMessage(), e);
    } catch (IllegalAccessException e) {
        Log.e("TEST", e.getMessage(), e);
    }

它需要一些重构来捕获错误......