com.surelogic

Annotation Type MustInvokeOnOverride

@Documented
@Retention(value=RUNTIME)
@Target(value=METHOD)
public @interface MustInvokeOnOverride

Declares that the method to which this annotation is applied must be invoked by any method that directly overrides it.

Any method that overrides a method annotated @MustInvokeOnOverride must also be annotated @MustInvokeOnOverride unless it is declared to be final or declared within a final class. It is a modeling error if it is not.

It is a modeling error to place this annotation on a method declared to be final or declared within a final class

Semantics:

Mandates that the annotated method is invoked at runtime when invoked even if subtypes override the method.

Examples:

The Activity class requires that "derived classes must call through to the super class's implementation" for several methods. This requirement can be documented with this annotation as shown below for the onCreate method.

 package android.app;
 
 public class Activity extends ... {
   @MustInvokeOnOverride
   protected void onCreate(Bundle savedInstanceState) {
     ...
   }
   ...
 }
 

The below code shows a derived class, Earthquake, that correctly invokes the onCreate method in its super class. Note that the onCreate method in the Earthquake class is not annotated @MustInvokeOnOverride because the class is declared to be final.

 public final class Earthquake extends Activity {
   @Override
   protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     
     setContentView(R.layout.main);
   }
   ...
 }
 

Javadoc usage notes:

This annotation may placed in Javadoc, which can be useful for Java 1.4 code which does not include language support for annotations, via the @annotate tag.

 public class Activity extends ... {
   /**
    * @annotate MustInvokeOnOverride
    */
   protected void onCreate(Bundle savedInstanceState) {
     ...
   }
   ...
 }