Spring Boot 2.0 Projects

Companion objects

An object declaration inside a class can be specified as a companion object of it, just like in the following code:

class Bean {    companion object Factory {        fun create() : Bean = Bean();    }}

This means that methods of object declaration inside can be invoked by just specifying the name of the outer class, as follows:

var bean = Bean.create();

A companion object is initialized when the outer class enclosing it is loaded similarly to a static initializer in Java.