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Project Lombok for reducing Java boilerplate. Covers annotations for getters, setters, constructors, builders, logging, and more. Based on production patterns from castellino and gestionale-presenze projects. USE WHEN: user mentions "lombok", "@Data", "@Builder", "@Slf4j", asks about "boilerplate reduction", "getters/setters", "@RequiredArgsConstructor", "@Value" DO NOT USE FOR: Java language features - use `java` skill instead DO NOT USE FOR: MapStruct integration - use `mapstruct` skill DO NOT USE FOR: Spring annotations - use `backend-spring-boot` skill
npx skill4agent add claude-dev-suite/claude-dev-suite lombokDeep Knowledge: Usewith technology:mcp__documentation__fetch_docsfor comprehensive documentation.lombok
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.34</version>
<optional>true</optional>
</dependency>
<!-- For MapStruct compatibility -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok-mapstruct-binding</artifactId>
<version>0.2.0</version>
</dependency>@Data
public class User {
private Long id;
private String name;
private String email;
}
// Generates:
// - @Getter for all fields
// - @Setter for all non-final fields
// - @ToString
// - @EqualsAndHashCode
// - @RequiredArgsConstructorpublic class User {
@Getter @Setter
private String name;
@Getter // Read-only
private final String email;
@Setter(AccessLevel.PROTECTED)
private String internalId;
}@NoArgsConstructor
@AllArgsConstructor
public class User {
private Long id;
private String name;
}
@RequiredArgsConstructor
public class UserService {
private final UserRepository userRepository; // Included in constructor
private final UserMapper userMapper; // Included in constructor
private String cacheName; // NOT included
}@Data
@Builder
public class User {
private Long id;
private String name;
private String email;
@Builder.Default
private UserStatus status = UserStatus.ACTIVE;
}
// Usage
User user = User.builder()
.name("John")
.email("john@example.com")
.build();
// With toBuilder for updates
User updated = user.toBuilder()
.name("Jane")
.build();@Value
public class UserResponse {
Long id;
String name;
String email;
LocalDateTime createdAt;
}
// Generates:
// - All fields are private final
// - @AllArgsConstructor
// - @Getter (no setters)
// - @ToString
// - @EqualsAndHashCode@Entity
@Table(name = "users")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
@EntityListeners(AuditingEntityListener.class)
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@Column(nullable = false)
private String name;
@Column(unique = true, nullable = false)
private String email;
@Enumerated(EnumType.STRING)
@Builder.Default
private UserStatus status = UserStatus.ACTIVE;
@CreatedDate
@Column(updatable = false)
private LocalDateTime createdAt;
@LastModifiedDate
private LocalDateTime updatedAt;
// Exclude from toString/equals for performance
@ToString.Exclude
@EqualsAndHashCode.Exclude
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "department_id")
private Department department;
}@Service
@RequiredArgsConstructor
@Slf4j
public class UserServiceImpl implements UserService {
private final UserRepository userRepository;
private final UserMapper userMapper;
private final PasswordEncoder passwordEncoder;
@Override
public UserResponse create(CreateUserRequest dto) {
log.info("Creating user: {}", dto.getEmail());
User user = userMapper.toEntity(dto);
return userMapper.toResponse(userRepository.save(user));
}
}@Slf4j // SLF4J logger
public class UserService {
public void process() {
log.info("Processing...");
log.debug("Debug info: {}", data);
log.error("Error occurred", exception);
}
}
@Log4j2 // Log4j2 logger
@CommonsLog // Apache Commons Logging
@JBossLog // JBoss Logging// Request DTO
@Data
public class CreateUserRequest {
@NotBlank
private String name;
@Email
private String email;
@Size(min = 8)
private String password;
}
// Response DTO (immutable)
@Value
@Builder
public class UserResponse {
Long id;
String name;
String email;
UserStatus status;
LocalDateTime createdAt;
}public void readFile(String path) throws IOException {
@Cleanup InputStream in = new FileInputStream(path);
// in.close() called automatically
}@SneakyThrows // Wraps checked exception
public String readConfig() {
return Files.readString(Path.of("config.json"));
}public class Counter {
@Synchronized
public void increment() {
// Thread-safe
}
}@Value
@With
public class Point {
int x;
int y;
}
Point p1 = new Point(1, 2);
Point p2 = p1.withX(5); // Point(5, 2)| Annotation | Purpose |
|---|---|
| Getter, Setter, ToString, Equals, Constructor |
| Immutable class |
| Builder pattern |
| Constructor for final fields |
| Logger field |
| Exclude from toString |
| Exclude from equals/hashCode |
| Scenario | Use Instead |
|---|---|
| Java core language | |
| MapStruct mapping | |
| Spring annotations | |
| JPA entities complex logic | Manual implementation |
| Public API design | Explicit methods for clarity |
| Anti-Pattern | Why It's Bad | Correct Approach |
|---|---|---|
| @Data on JPA entities | toString/equals issues | Use @Getter/@Setter selectively |
| Not excluding lazy relations | LazyInitializationException | Use @ToString.Exclude |
| @EqualsAndHashCode on entities | Proxy issues | Use @EqualsAndHashCode(onlyExplicitlyIncluded = true) |
| @SneakyThrows everywhere | Hides exceptions | Use proper exception handling |
| @Builder without @Default | Null fields | Add @Builder.Default |
| @Value with mutable fields | Breaks immutability | Use only immutable types |
| Mixing @Data and manual methods | Confusing API | Be consistent |
| Not configuring in lombok.config | Inconsistent behavior | Use lombok.config file |
| Issue | Cause | Solution |
|---|---|---|
| "Cannot find symbol" for getters | IDE not processing | Enable annotation processing |
| LazyInitializationException | toString on lazy relation | Add @ToString.Exclude |
| MapStruct not working | Wrong processor order | Lombok before MapStruct |
| Builder missing fields | No @Builder.Default | Add defaults or check config |
| StackOverflowError in equals | Circular reference | Exclude relation fields |
| IDE shows errors but compiles | IDE cache | Invalidate caches/restart |
| @Slf4j logger not found | SLF4J not in classpath | Add SLF4J dependency |
| Generated code not visible | delombok needed | Run delombok task |
Deep Knowledge: Usewith technology:mcp__documentation__fetch_docsfor comprehensive documentation.lombok