RequiredArgsConstructor access

### RequiredArgsConstructor Usage and Access Issues in Java Lombok

When using `@RequiredArgsConstructor` from the Lombok library, several common issues can arise especially during upgrades or when integrating with newer versions of Java. The principle behind Lombok is to generate boilerplate code at compile time which sometimes leads to discrepancies between source files and compiled classes[^1].

For instance, if a project uses an older version of Lombok (e.g., 1.16.x), upgrading to Java 8 or higher might cause problems because Lombok relies on internal APIs under `com.sun.tools.javac`. These APIs may change across different JDK releases leading to compatibility issues.

To resolve these issues:

#### Updating Lombok Version
Ensure that the latest stable release of Lombok is used within your dependency management tool such as Maven or Gradle.

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.24</version>
    <scope>provided</scope>
</dependency>

Or for Gradle users:

compileOnly 'org.projectlombok:lombok:1.18.24'
annotationProcessor 'org.projectlombok:lombok:1.18.24'

This ensures better support for modern Java features while maintaining backward compatibility where possible[^2].

#### Handling Missing Classes Due to Module System Changes
With the introduction of modules starting from Java 9, certain packages previously available by default are no longer included automatically. Specifically, any references to `javax.annotation`, commonly found alongside `sun.misc.*`, need explicit inclusion via dependencies like so:

<dependency>
    <groupId>javax.annotation</groupId>
    <artifactId>javax.annotation-api</artifactId>
    <version>1.3.2</version>
</dependency>

Such adjustments help prevent compilation errors related to missing symbols caused by changes in how libraries are packaged post-Java 8[^3].

#### Example Code Demonstrating Proper Use of @RequiredArgsConstructor
Here’s a simple example demonstrating correct usage along with addressing potential access modifiers conflicts:

import lombok.RequiredArgsConstructor;

// Using final fields forces constructor generation through @RequiredArgsConstructor
@RequiredArgsConstructor(staticName = "of") // Optional customization point
public class User {
    
    private final String name;
    private final int age;

    public static void main(String[] args){
        var user = User.of("John Doe", 30);
        System.out.println(user.getName());
    }

    // Getter methods required since they aren't auto-generated unlike setters
    public String getName(){
        return this.name;
    }
}

In cases involving inheritance hierarchies or interfaces implementing multiple constructors, ensure all necessary parameters are covered either directly inside child classes or passed upwards appropriately.

--related questions--

1. What other annotations does Lombok offer besides `@RequiredArgsConstructor`?
2. How do module system changes impact third-party library integrations beyond just annotation processors?
3. Can you provide more examples showcasing advanced usages of Lombok's capabilities?
4. Are there alternatives to Lombok worth considering for reducing boilerplate code in Java applications?