com.github.dm.jrt.annotation

Annotation Type Output

@Target(value=METHOD)
@Retention(value=RUNTIME)
public @interface Output

Through this annotation it is possible to indicate that the result returned by the target object method must be dispatched in an asynchronous way.
If, on the contrary, this annotation is missing, be aware that the proxy method will block until the target one completes, even if no result is expected (that is, the method returns a void result).

This annotation is used to decorate methods that are to be invoked in an asynchronous way.
Note that the piece of code inside such methods will be automatically protected so to avoid concurrency issues. Though, other parts of the code inside the same class will be not.
In order to prevent unexpected behaviors, it is advisable to avoid using the same class fields (unless immutable) in protected and non-protected code, or to call synchronous methods through routines as well.

The only use case in which this annotation is useful, is when an interface is used as a proxy of another class methods. The interface can return the output in an asynchronous way. In such case, the value specified in the annotation will indicate the mode in which the output is transferred outside the routine.

For example, a method returning an integer:

     

         public int sum(int i1, int i2);
     
 

can be proxied by a method defined as:

     

         @Output
         public OutputChannel<Integer> sum(int i1, int i2);
     
 

The interface can also return an array or list of outputs:

     

         @Output(OutputMode.COLLECTION)
         public List<Integer> sum(int i1, int i2);
     
 

Note that the transfer mode is specifically chosen through the annotation mode attribute (it's CHANNEL by default).

Remember also that, in order for the annotation to properly work at run time, you will need to add the following rules to your Proguard file (if employing it for shrinking or obfuscation):

     

         -keepattributes RuntimeVisibleAnnotations
         -keepclassmembers class ** {
              @com.github.dm.jrt.annotation.Output *;
         }
     
 

Created by davide-maestroni on 05/24/2015.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
Output.OutputMode	value The output transfer mode.

Element Detail

value

public abstract Output.OutputMode value

The output transfer mode.

Returns:

the mode.

Default:

com.github.dm.jrt.annotation.Output.OutputMode.CHANNEL