If you need step guarantees in multiple mono, and you need to inherit values from each step and batch them, how do you do that wisely?

Question

In the process of using the project reactor If you need step guarantees in multiple mono, and you need to inherit values from each step and batch them, how do you do that wisely?

Here's the method I'm currently using:

public Mono someMethod(String id, Test test) {
    return longMonoResult(id)
        .flatMap(aLong -> {
            test.setValue(aLong)
            return booleanMonoResult(aLong)
                .flaMap(aBoolean -> {
                    return longMonoResult2(aBoolean)
                             .map(aLong2 -> test);
                })
        })
}

This looks very poorly readable in my opinion. Also, the more steps are added, the deeper the indentation becomes.

Is there any way to separate the steps?

user_5314546 · Answer

First off you really shouldn't mutate input parameters like test.setValue(aLong).

As to the nesting you can do something like I suggested here: How to use Java 8 Optionals, performing an action if all three are present?

There are also things like Tuples if you don't want to write a custom Type every time. I personally feel having named values is worth it.

If you need step guarantees in multiple mono, and you need to inherit values from each step and batch them, how do you do that wisely?

1 Answers