Project Lombok in AEM Projects

PublishedMarch 17, 2024

Viewed188 times

In AEM backend Java development, Sling Models are utilized to retrieve dialog values using annotations. However, writing boilerplate code such as getter methods for passing these values to HTL can be tedious. To simplify this process, Project Lombok can be integrated, automatically generating the necessary boilerplate code with annotations like @Getter. This streamlines development tasks by eliminating the need for manual getter method creation.

Lombok is a Java library designed to minimize boilerplate code by providing annotations to generate getters, setters, constructors, and other repetitive code structures. By leveraging Lombok, developers can produce cleaner and more concise code without sacrificing functionality. To incorporate Lombok into the AEM project, you'll need to include the Maven dependency in both the root and core pom.xml files.

pom.xml

<dependency>
  <groupId>org.projectlombok</groupId>
  <artifactId>lombok</artifactId>
  <version>${lombok.version}</version>
  <scope>provided</scope>
</dependency>

core / pom.xml

<dependency>
  <groupId>org.projectlombok</groupId>
  <artifactId>lombok</artifactId>
</dependency>

For the demonstration purpose, let's consider a component with a dialog comprising a textfield (title), tagfield (tags), datepicker (publishDate), and select (category) field. In a Sling Model, the typical approach involves creating getter methods for each variable needed for access from HTL.

Article.java

public class Article {
  @ValueMapValue
  String title;

  @ValueMapValue
  String[] tags;

  @ValueMapValue
  Date publishDate;

  @ValueMapValue
  String category;
  
  public String getTitle() {
    return title;
  }
  
  public String[] getTags() {
    return tags;
  }
  
  public Date getPublishDate() {
    return publishDate;
  }
  
  public String getCategory() {
    return category;
  }
}

By leveraging Lombok, we can simplify and enhance the Article Sling Model impplementation as follows. @Getter annotation from Lombok automatically generates getter methods for the fields within the class.

Article.java

import lombok.Getter;

public class Article {
  @Getter
  @ValueMapValue
  String title;

  @Getter
  @ValueMapValue
  String[] tags;

  @Getter
  @ValueMapValue
  Date publishDate;

  @Getter
  @ValueMapValue
  String category;
}

You can make the Sling Model even more concise if all the properties require getter methods. Instead of adding @Getter to each field, simply use the annotation at the class level to apply it to all fields at once.

Article.java

import lombok.Getter;

@Getter
public class Article {
  @ValueMapValue
  String title;

  @ValueMapValue
  String[] tags;

  @ValueMapValue
  Date publishDate;

  @ValueMapValue
  String category;
}