Spring 5.0 By Example

Objects

The singleton pattern is commonly used in applications, and Kotlin provides an easy way to do that without much boilerplate code.

We can instruct Kotlin to create a singleton object using the object keyword. Once again,  Kotlin used Scala as a reference because there are the same functionalities in the Scala language.

Let's try it:

object BookNameFormatter{  fun format(book: Book):String = "The book name is" + book.name}

We have created a formatter to return a message with the book name. Then, we try to use this function:

val springFiveOld = Book("Claudio E. de Oliveira","Spring 5.0 by Example","Amazing example of Spring Boot Apps",false)BookNameFormatter.format(springFiveOld)

The function format can be called in a static context. ...