public class EventAgent
{
    // private constructor ensures no other instances
    private EventAgent() { }
    // static member variable and method enables callers 
    // to get to the one-and-only object instance
    private static final EventAgent SINGLE_INSTANCE = new EventAgent();
    public static EventAgent getInstance() 
    {
        return SINGLE_INSTANCE; 
    }
    ...
}

Example 3: The Singleton design pattern.