android intent-filter action name, how does it work?

android intent-filter action name, how does it work?

I have one Activity called IntentTest, manifest:
<activity
android:name=".IntentTest
android:label="Intent Test" >
<intent-filter>
<action android:name="blah" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
I start this activity with
Class newClass = Class.forName("com.example.wissenstor.IntentTest");
Intent i = new Intent(this, newClass);
startActivity(i);
In the intent-filter I set the action name to "blah", why can I still
start the activity with "com.example.wissenstor.IntentTest"? I appreciate
your help.