Contract API testing with Builder Pattern using Lombok

Builder Pattern

The Builder is a design pattern designed to provide a flexible solution to various object creation problems in object-oriented programming. The Builder pattern allows the creation of different representations of an object using the same construction code.  The Builder design pattern solves problems like:

1. How can a class (the same construction process) create different representations of a complex object?
2. How can a class that includes creating a complex object be simplified?

POJO classes without Builder pattern gets very complex due to Telescopic constructors and makes the coding very complex.

The code without builder pattern (the common way) will have Telescopic constructors as shown below

Calling the builder pattern POJO

Calling builder pattern POJO requires one to call the builder method and then access its methods as shown for posts.getAuthor()

var posts = new Posts.Builder().build()
var post = response.getBody().as(posts.getClass());
var author = posts.getAuthor()

 Project Lombok’s @Builder is a useful mechanism for using the Builder pattern without writing boilerplate code. We can apply this annotation to a Class or a method.Lombok plugin

To work with Lombok plugin of builder pattern in IntelliJ, we need to install the plugin in IntelliJ IDE and add an dependency in our project as shown below

Once the plugin is installed, we can then start using it in our POJO classes. We can replace the above POJO class to something like one shown below

@Data
@Builder
public class Posts {
    private int id;
    private String title;
    private String author;
}

The detailed discussion is available here in this video

Thanks for reading the article and watching those video !

Hope you how contract API testing is done using Builder patterns in real time environments.

Thanks,

Karthik KK