Lombok: RequiredArgsConstructor not working

Question

It seems that @RequiredArgsConstructor not working in the code below. Why is it?

import java.io.Serializable;

import lombok.Data;
import lombok         


        

Answer 1

It's also worth noting for future readers that @Data also provides @RequiredArgsConstructor, so using both annotations isn't necessary :)

Answer 2

According to Documentation, Required arguments are final fields and fields with constraints such as @NonNull.

You need to make username as @NonNull

@NonNull private String username;

And you need to make them final too.

Answer 3

Did you installed Lombok plugin in intellij ?

If not then

File -> Settings -> Plusings: Search for Lombok (CodeStream) version.

Restart the IDE and it should be fixed.

Double Check:

• You have Lombok library installed using Maven or Gradle.
• Enabled Annotation Processors from intellij IDE from File -> Settings: Search for Annotation Processors

Answer 4

Try changing project/module JDK to 1.8.

Project Structure -> Project Settings->Project SDK and Project Language Level

Answer 5

The argument fields for @RequiredArgsConstructor annotation has to be final. So this fix will work:

private final String username;

The IDE IntelliJ makes the variable grey (inactive status) when final keyword missed, which is very helpful to detect this kind of mistake.