To Discuss or Not To Discuss

Hi,

As you are a loyal reader of my newsletter, you probably know that I publish content on three different channels.

• This newsletter comes out on Mondays and Thursdays.
• A LinkedIn post on Tuesdays and Fridays
• And every Wednesday, I write a blog

Each Content Targets a Different Audience

The newsletter is infotainment. Its purpose is to entertain you, to start your day with a fresh thought. And it allows you to gain a deeper insight into my thoughts and perspectives.

LinkedIn is for reach. At the end of the day, I am a consultant, and this is often where I make my first contact with decision-makers.

And my blog is SEO-optimized, intended to provide quick answers to common questions. (This wasn’t always the case - but that’s a story for another time)

My Blog Yesterday Was a Puzzle

It covers event handling in Spring.

ApplicationEvents also provide the option to formulate conditions with SpEL expressions.

For example, if you have a CustomSpringEvent:

public class CustomSpringEvent {
    private boolean publish;

    public CustomSpringEvent(boolean publish) {
        this.publish = publish;
    }

    public boolean isPublish() {
        return publish;
    }
}

Then with the following configuration, you can ensure that only events with the publish flag are processed:

@EventListener(condition = "#event.publish")
public void handleEvent(CustomSpringEvent event) {
    log.info("handled " + event);
}

However, I don’t want to promote this feature. SpEL expressions are expressed as a string. So, if we rename publish to distribute, the compiler can’t help us here. The code will still compile. But the code is flawed.

SpEL expressions are a perfect example of Murphy’s law :

“Anything that can go wrong will go wrong.”

So, what should I do?

My blog is beginner content. Those who come across this article through Google are still trying to grasp the basics of Spring.

If I explain the Condition-Feature, it will be used.

If I explain in detail why this feature should be avoided, then it’s out-of-scope.

But beginners also have the right to read this discussion and form their own opinion.

So, what should I do? 😕

This time, I didn’t delve into it. Is that the right approach? I don’t know.

Rule the Backend,

~ Marcus