Lombok @Builder: "java: cannot find symbol builderclass" - A common pitfall and how to fix it
Problem: You're using Lombok's @Builder annotation in your Java project, but you're encountering the error "java: cannot find symbol builderclass". This means the compiler can't find the generated builder class, preventing you from using Lombok's builder functionality.
Rephrased: You want to use Lombok's @Builder to simplify object creation, but it's throwing an error, making it impossible to use.
Scenario: You have a simple Java class with the @Builder annotation:
import lombok.Builder;
import lombok.Getter;
import lombok.Setter;
@Getter
@Setter
@Builder
public class Person {
private String name;
private int age;
}
Original Code: You might try creating an instance like this:
Person person = Person.builder() // Error: cannot find symbol builderclass
.name("John")
.age(30)
.build();
Analysis: The error "java: cannot find symbol builderclass" arises when the compiler can't find the generated builder class. This happens because Lombok's builder generation requires specific configurations and can be affected by factors like:
- Missing Lombok dependency: Ensure you have the latest Lombok dependency added to your project's build file (Maven or Gradle).
- Incorrect Lombok version: The error could be related to an outdated Lombok version. Try upgrading to the latest version.
- Incorrect compiler settings: If you're using IDEs like Eclipse or IntelliJ, ensure your compiler settings are properly configured to recognize Lombok's annotations.
- Compiler plugin: Some IDEs might require installing a Lombok plugin for proper annotation processing.
- Incorrect project setup: Make sure your project is set up correctly to use Lombok. This involves adding the necessary dependencies and configuration to your build tool.
Example:
- Maven: Add the following dependency to your
pom.xml:
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.24</version>
<scope>provided</scope>
</dependency>
- Gradle: Add the following dependency to your
build.gradle:
implementation("org.projectlombok:lombok:1.18.24")
annotationProcessor("org.projectlombok:lombok:1.18.24")
Solution:
- Check for Lombok dependency: Double-check that you have the Lombok dependency included in your project's build file.
- Update Lombok version: If you're using an older version of Lombok, try upgrading to the latest release.
- Configure your IDE: Make sure Lombok is properly configured within your IDE. This often involves installing a plugin or adjusting compiler settings.
- Rebuild your project: After making any changes, rebuild your project to ensure the changes are reflected in the generated code.
Additional Value:
- Consider alternatives: If you encounter persistent issues, explore other ways to generate builders like Apache Commons Lang's "Builder" pattern or using a code generation tool.
- Learn about lombok: Explore the official Lombok documentation to understand the intricacies of its various annotations and their usage.
- Use Lombok effectively: Leverage Lombok's features to write cleaner and more concise code, reducing boilerplate and improving code readability.
References:
- Lombok Documentation: https://projectlombok.org/
- Lombok GitHub: https://github.com/projectlombok/lombok
By following these steps and understanding the underlying issues, you can effectively resolve the "java: cannot find symbol builderclass" error and harness the power of Lombok's @Builder annotation for streamlined object construction.
