Can one class extend two classes?

Question

My class should extend two classes at the same time:

public class Preferences extends AbstractBillingActivity {  public class Preferences extends PreferenceActivity { 

How to do so?

Upd. Since this is not possible, how should I use that AbstractBillingActivity with Preferences then?

Upd2. If I go with interfaces, should I create:

1. BillingInterface

   public interface BillingInterface extends PreferenceActivity, AbstractBillingActivity {  } 

2. PreferenceActivity

   public interface PreferenceActivity {  } 

3. AbstractBillingActivity

   public interface AbstractBillingActivity {          void onCreate(Bundle savedInstanceState);  } 

and then

public class Preferences implements BillingInterface { 

Answer 1

Java does not support multiple inheritance.

There are a few workarounds I can think of:

The first is aggregation: make a class that takes those two activities as fields.

The second is to use interfaces.

The third is to rethink your design: does it make sense for a Preferences class to be both a PreferenceActivity and an AbstractBillingActivity?