Hands-On Microservices with Kotlin

Reactive programming

We are quite familiar with imperative programming: in our software, we ask to do something and expect a result and meanwhile, we wait, our action is blocked expecting a result. Consider this small pseudo code as an example:

var someVariable = getData()print(someVariable)

In this couple of instructions, we will set the content of a variable from the output of a function that will return data; when the data is available, we will print it out. The really important part of this small piece of code is that our program stops until we completely get the data, this is what is called a blocking operation.

There is a way to bypass this limitation that has been used extensively in the past. For example, we could create a separate ...