Detailed explanation of the steps to integrate Lombok in SpringBoot

1. Introduction

In Java development, we often need to write a large amount of template code, such as getter and setter methods, constructors, toString, equals and hashCode, etc. Although these codes are simple, they are very cumbersome and prone to errors. The emergence of the Lombok library is to help us automatically generate these template codes so that we can focus more on the implementation of business logic. This article will introduce in detail how to integrate Lombok in Spring Boot project, as well as some common annotations for Lombok.

2. Integrate Lombok

1. Install the Lombok plug-in

Before we start using Lombok, we need to make sure that the Lombok plugin is installed in the development environment. For IntelliJ IDEA users, you can install it in two ways:

Directly fromJetBrains Plugin MarketDownload the plugin and install it.
In IDEA's Settings (Windows) or Preferences (Mac), find the Plugins menu, search for Lombok and install.

2. Add Lombok dependencies

On the projectIn the file, add Lombok's dependencies:

<dependency>
    <groupId></groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.6</version>
    <scope>provided</scope>
</dependency>

Starting with Spring Boot 2. version, Lombok dependencies are already built into starter, so there is no need to be explicitly added.

3. Use Lombok annotations

Lombok provides a series of annotations that can help us automatically generate template code. Here are some commonly used annotations and their usage:

1.1、@Data

The @Data annotation is a very convenient annotation provided by Lombok. It is equivalent to @Setter, @Getter, @RequiredArgsConstructor, @ToString, @EqualsAndHashCode. Using the @Data annotation, we can automatically generate getter/setter, constructor, toString, equals, and hashCode methods for the class.

import ;

@Data
public class User {
    private String name;
    private int age;
}

1.2. @NoArgsConstructor, @AllArgsConstructor and @RequiredArgsConstructor

These three annotations are used to generate constructor methods:

@NoArgsConstructor: Generate a parameterless construction method.
@AllArgsConstructor: Generate a constructor containing all attributes.
@RequiredArgsConstructor: Generate all non-finalThe method of constructing attributes.

import ;
import ;
import ;

@NoArgsConstructor
@AllArgsConstructor
@RequiredArgsConstructor
public class User {
    private String name;
    private final int age;
}

1.3. @Getter and @Setter

These two annotations are used to generate getter and setter methods. If the attribute isfinalThe setter method is usually not required.

import ;
import ;

public class User {
    @Getter @Setter
    private String name;
    @Getter
    private int age;
}

3. How Lombok works

Lombok automatically generates code for us during the compilation stage through annotation processor. It modifies Java's abstract syntax tree (AST), adds the corresponding tree nodes defined by the annotation, and then generates the bytecode file from javac. This means that the code generated using Lombok does not exist at runtime, it is only processed by Lombok at compile time.

4. Summary

Lombok is a powerful Java library that simplifies the writing of Java code through annotations and reduces the generation of template code. Integrating Lombok in Spring Boot project is very simple, you just need to add dependencies and install plugins. Lombok's annotations such as @Data, @NoArgsConstructor, @AllArgsConstructor, @RequiredArgsConstructor, @Getter and @Setter, etc., greatly improve development efficiency and code readability. While Lombok has many advantages, when used in a team, you need to make sure that all members understand and accept Lombok to maintain consistency in the style of code.

The above is the detailed explanation of the steps for SpringBoot integrating Lombok. For more information about SpringBoot integrating Lombok, please pay attention to my other related articles!