WARN/dalvikvm(990): No implementation found for native Landroid/os/SystemProperties;.native_get (Ljava/lang/String;)Ljava/lang/String;

[bazookier]

I use adb shell to type dalvikvm to run java program whose java
calling stack invoked the native_get method of
android.os.SystemProperties.

From ddms, the warning is:09-05 09:52:31.715: WARN/dalvikvm(990): No
implementation found for native Landroid/os/
SystemProperties;.native_get (Ljava/lang/String;)Ljava/lang/String;

So in java code, what library shuold be loaded or any other ways to
solve this problem?

[Dianne Hackborn]

If you want to use the framework APIs, which have lots of native code behind them, you need to run dalvik with the native code included in it.  I believe the command is app_process -- you can look at some of the shell commands like "am" and "pm" to see how they are launched.

Note that this is not a typical way to launch the platform code, so if you aren't careful you will find various things that don't work or behave strangely; for the most part the platform really wants to be running and a processes launched and controlled by the activity manager.

--
Dianne Hackborn
Android framework engineer
hac...@android.com

Note: please don't send private questions to me, as I don't have time to provide private support, and so won't reply to such e-mails.  All such questions should be posted on public forums, where I and others can see and answer them.

[bazookier]

Thanks, Dianne!

Can you provide more details about including the native code while
using dalvikvm to run the programme?
Do you mean using System.load("somelib.so"); to include the native
code?
Or using any dalvikvm options to include that?

And how to understand your propose of using command app_process and am
or pm?

May silly questions. But I really do not understand!

On 9月6日, 上午12时13分, Dianne Hackborn <hack...@android.com> wrote:
> If you want to use the framework APIs, which have lots of native code behind
> them, you need to run dalvik with the native code included in it. I believe
> the command is app_process -- you can look at some of the shell commands
> like "am" and "pm" to see how they are launched.
>
> Note that this is not a typical way to launch the platform code, so if you
> aren't careful you will find various things that don't work or behave
> strangely; for the most part the platform really wants to be running and a
> processes launched and controlled by the activity manager.
>
>
>
> On Sat, Sep 5, 2009 at 7:46 AM, bazookier <geelphe...@gmail.com> wrote:
>
> > I use adb shell to type dalvikvm to run java program whose java
> > calling stack invoked the native_get method of
> > android.os.SystemProperties.
>
> > From ddms, the warning is:09-05 09:52:31.715: WARN/dalvikvm(990): No
> > implementation found for native Landroid/os/
> > SystemProperties;.native_get (Ljava/lang/String;)Ljava/lang/String;
>
> > So in java code, what library shuold be loaded or any other ways to
> > solve this problem?
>
> --
> Dianne Hackborn
> Android framework engineer

> hack...@android.com

[bazookier]

Can anyone tell what should I do first?
Should I start some service?

[fadden]

Two things need to happen:

(1) The necessary shared libraries need to be loaded.
(2) The various native methods need to be registered.

In frameworks/base/core/jni/AndroidRuntime.cpp you can see
AndroidRuntime::startReg(), which takes care of registering the native
methods associated with the Android application framework. This is
called from AndroidRuntime::start, which is where the framework
initialization begins.

I believe what hackbod was suggesting earlier is that you should look
at the implementation of "am" to see how it starts up, and perhaps do
something similar.

[Nitin]

Hi All,

I am loading the service in the systemserver main method and also i am
registering the native methods by registered to AndroidRuntime:.
Once this is done and i flash the phone its not getting boot up. Can
you please tell if i am missing something or something else need to be
done. please give your suggestion

Regards
Nitin