Java Events in .NET

J-Integra® for .NET currently supports the mapping of Java events onto .NET events. For an example, see Access Java Events from .NET Using J-Integra® for .NET. The following Java constructs are mapped onto .NET constructs:

1. Java event listener - an interface which extends java.util.EventListener. The following code snippets demonstrates this mapping:

   In Java:

    public interface MyEventHandlerListener extends java.util.EventListener {
       public int MyEvent1(Object sender, boolean e, int i);
       public boolean MyEvent2(float f);
    }

   For each of the above methods a .NET delegate must be defined. In C#:

    public class MyEventsListener {
       public delegate int MyEvent1(bool e, int i);
       public delegate bool MyEvent2(float f);
    }

2. Java event source - an object which provides at least 2 methods for adding and removing with a single parameter which is a Java event listener.

    public class MyClassWithEvents {
       public void addMyEventHandlerListener(MyEventHandlerListener listener) {
         ...
       }
       public void removeMyEventHandlerListener(MyEventHandlerListener listener) {
         ... 
       }
    }

   Each Java event method is mapped to and event in C#. Note that each method in the interface gets it's own event. This is a fundamental difference in event handling between .NET and Java:

    public class MyClassWithEvents {
       public event MyEventsListener.MyEvent1 MyEvent;
       public event MyEventsListener.MyEvent2 MyEvent;
       .
       .
       .
    }