Builder pattern

What is the Builder Pattern?

The Builder pattern is one of the Design Patterns in the Creational Design Pattern group that is used to build complex objects with a large number of classes and parameters. It's really not very useful in small classes that simply don't have many constructors.

When a program has many classes, parameters, as well as many constructors, using the Factory Pattern or Abstract Factory Pattern will be very complicated. So we can use the Builder Pattern to overcome.

We will make a simple program with the Builder Pattern to help you understand how it should work and under what circumstances.

Let's create a class with certain properties, specifically as follows:

• Variables: computerCase, CPU, motherboard, GPU, HDD, operatingSystem are of type String.
• Variables: powerSupply, amountOfRAM are of type INT.

All the above variables must be encapsulated (Private).

One problem here is that even such a small and simple class requires a very large constructor.

We can create more constructors in class using Builder Pattern.

To do this, we will nest a static Builder class inside the Computer class.

This Builder way will be used to build objects in a clean and readable way, unlike the code above.

This nested class has the same properties as the Computer class and uses them to construct Computer objects.

Once all is set up, we can initialize the Computer Objects.

This is a shorter and cleaner way of writing it.

You can practice with other simple programs to get used to this pattern. I hope this tutorial will help you understand what the Builder Pattern is and how to implement it in Java.