Question

I have several services that are listening for Spring events to make changes to my underlying data model. These all work by implementing ApplicationListener<Foo>. Once all of the Foo listeners modify the underlying data model, my user interface needs to refresh to reflect the changes (think fireTableDataChanged()).

Is there any way to ensure that a specific listener for Foo is always last? Or is there any way to call a function when all other listeners are done? I’m using annotation based wiring and Java config, if that matters.

Answer 1

All your beans implementing ApplicationListener should also implement Ordered and provide reasonable order value. The lower the value, the sooner your listener will be invoked:

class FirstListener implements ApplicationListener<Foo>, Ordered {
    public int getOrder() {
        return 10;
    }
    //...
}

class SecondListener implements ApplicationListener<Foo>, Ordered {
    public int getOrder() {
        return 20;
    }
    //...
}

class LastListener implements ApplicationListener<Foo>, Ordered {
    public int getOrder() {
        return LOWEST_PRECEDENCE;
    }
    //...
}

Moreover you can implement PriorityOrdered to make sure one of your listeners is always invoked first.