Mixing Kotlin and Java in a project

Using different languages within the same project is quite common; I have encountered projects where a mix of Java and Scala files formed the code base. Could we do the same with Kotlin? Absolutely. Let's work on the project we created earlier in the Kotlin with Gradle section. You should see the following directory structure in your IntelliJ (the standard template for a Java/Kotlin project):

Project layout

You can place the Java code within the java folder. Add a new package to the java folder with the same name as the one present in the kotlin folder: com.programming.kotlin.chapter01. Navigate to New | Java class named CarManufacturer.java and use the following code for the purpose of the exercise:

    public class CarManufacturer { 
      private final String name; 
      public CarManufacturer(String name) { 
        this.name =...