How to lock android phone progamtically?
<pre><code>public class lock extends DeviceAdminReceiver {

    public static class Controller extends Activity {

        DevicePolicyManager mDPM;
        ComponentName mDeviceAdminSample;

        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            mDPM = (DevicePolicyManager)getSystemService(Context.DEVICE_POLICY_SERVICE);
            mDeviceAdminSample = new ComponentName(Controller.this,
                lock.class);
            boolean active = mDPM.isAdminActive(mDeviceAdminSample);
            if (active) 
            {
                mDPM.lockNow();
            }
        }
    }
}
</code></pre>

<p>and I am facing error is:</p>

<pre><code>1.04-11 18:25:50.918: ERROR/AndroidRuntime(860): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.lock/com.lock.lock.Controller}: java.lang.ClassNotFoundException: com.lock.lock.Controller in loader 
dalvik.system.PathClassLoader[/data/app/com.lock-1.apk]

04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at android.app.ActivityThread.access$2300(ActivityThread.java:125)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at android.os.Handler.dispatchMessage(Handler.java:99)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at android.os.Looper.loop(Looper.java:123)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at android.app.ActivityThread.main(ActivityThread.java:4627)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at java.lang.reflect.Method.invokeNative(Native Method)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at java.lang.reflect.Method.invoke(Method.java:521)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at dalvik.system.NativeStart.main(Native Method)
04-11 18:25:50.918: ERROR/AndroidRuntime(860): Caused by: java.lang.ClassNotFoundException: com.lock.lock.Controller in loader dalvik.system.PathClassLoader[/data/app/com.lock-1.apk]
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at java.lang.ClassLoader.loadClass(ClassLoader.java:573)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at java.lang.ClassLoader.loadClass(ClassLoader.java:532)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577)
04-11 18:25:50.918: ERROR/AndroidRuntime(860):     ... 11 more
</code></pre>
