java builder lombok

java builder lombok

I'm happy to help! However, since you requested me to respond in English only, I'll make sure my answer is straightforward and concise.

Lombok is a popular Java library that simplifies the coding process by automatically adding boilerplate code (such as getters and setters) for us. One of its key features is the Builder pattern implementation, which allows for more readable and maintainable code.

The main idea behind Lombok's Builder is to provide a way to construct objects in a fluent manner, making it easier to create complex objects with many dependencies. This is achieved by using a class that provides methods for setting properties and returning instances of itself (self-referential).

Here's an example of how you might use Lombok's Builder:

@Data
public class Person {
private String firstName;
private String lastName;
private int age;
@Builder
public Person(String firstName, String lastName, int age) {
this.firstName = firstName;
this.lastName = lastName;
this.age = age;
}
}
// Usage
Person person = new Person.Builder("John", "Doe", 30).build();

In this example, we define a Person class with three properties: firstName, lastName, and age. We then use Lombok's @Builder annotation to enable the Builder pattern. The builder() method is automatically generated by Lombok, which allows us to construct objects in a more readable way.

When you call new Person.Builder("John", "Doe", 30).build(), Lombok will generate the necessary code to create a new Person object with the specified properties and return an instance of itself. This makes it easier to create complex objects without having to write tedious boilerplate code.

Lombok's Builder also provides other benefits, such as:

Overall, Lombok's Builder is a powerful tool that can simplify your Java coding experience. It reduces boilerplate code, improves readability, and makes it easier to create complex objects.

So, there you have it! I hope this explanation has helped you understand how Lombok's Builder works in Java.

java builder pattern example

Here is an example of the Builder design pattern implemented in Java:

public abstract class Sandwich {
protected String bread;
protected List fillings;
public abstract void display();
public static class SandwichBuilder {
private String bread;
private List fillings = new ArrayList<>();
public SandwichBuilder(String bread) {
this.bread = bread;
}
public SandwichBuilder addFilling(String filling) {
this.fillings.add(filling);
return this;
}
public Sandwich build() {
Sandwich sandwich = new Sandwich();
sandwich.bread = this.bread;
sandwich.fillings = this.fillings;
return sandwich;
}
}
}
public class VeggieSandwich extends Sandwich {
@Override
public void display() {
System.out.println("Veggie Sandwich: " + bread);
for (String filling : fillings) {
System.out.println(" - " + filling);
}
}
}
public class MeatLoverSandwich extends Sandwich {
@Override
public void display() {
System.out.println("Meat Lover Sandwich: " + bread);
for (String filling : fillings) {
System.out.println(" - " + filling);
}
}
}

Here's how it works:

Here's how you would use this pattern:

public static void main(String[] args) {
Sandwich veggieSandwich = new Sandwich.SandwichBuilder("whole wheat")
.addFilling("avocado").addFilling("lettuce").build();
Sandwich meatLoverSandwich = new Sandwich.SandwichBuilder("sourdough")
.addFilling("beef").addFilling("bacon").build();
veggieSandwich.display();
System.out.println();
meatLoverSandwich.display();
}

This code creates two sandwiches with different fillings and displays their details.