Lombok detailed introduction

One 、Lombok brief introduction

Lombok It's a Java library , Can automatically insert editor and build tools , simplify Java Development . By adding comments , You don't need to write... For the class getter or eques Method , At the same time, log variables can be automated .

Simply speaking ：Lombok Can be simplified in the form of simple notes java Code , Improve the development efficiency of developers .

Two 、 Lombok Installation

Introduce dependencies

<dependency>
	<groupId>org.projectlombok</groupId>
	<artifactId>lombok</artifactId>
	<version>1.18.4</version>
	<scope>provided</scope>
</dependency>

Installing a plug-in

  3、 ... and 、 Use Lombok And the difference between not using

Don't use Lombok Annotations , Everyone should write these methods , so much trouble .

public class test {
    private Integer id;

    private String username;

    private Integer age;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "test{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", age=" + age +
                '}';
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        test test = (test) o;
        return Objects.equals(id, test.id) && Objects.equals(username, test.username) && Objects.equals(age, test.age);
    }

    @Override
    public int hashCode() {
        return Objects.hash(id, username, age);
    }
}

Use Lombok Annotations , Generated the required get、set、toString Other methods

@Data
public class test {
    private Integer id;

    private String username;

    private Integer age;
    
}

Four 、Lombok Commonly used annotations

@Setter Annotation in class or field , Annotations are generated for all fields at class time setter Method , When an annotation is on a field, it is generated only for that field setter Method .
@Getter The same as above , The difference is that what is generated is getter Method .
@ToString The annotation is in the class , add to toString Method .
@EqualsAndHashCode The annotation is in the class , Generate hashCode and equals Method .
@NoArgsConstructor The annotation is in the class , The construction method of generating parameterless .
@RequiredArgsConstructor The annotation is in the class , Generate construction methods for fields in the class that need special processing , such as final And quilt @NonNull Annotated fields .
@AllArgsConstructor The annotation is in the class , Generate the constructor that contains all the fields in the class .
@Data The annotation is in the class , Generate setter/getter、equals、canEqual、hashCode、toString Method , If final attribute , Will not generate setter Method .
@Slf4j The annotation is in the class , Generate log Variable , Strictly speaking, it's constant .private static final Logger log = LoggerFactory.getLogger(UserController.class);