Spring Boot Ultimate

A comprehensive skill for Spring Boot development providing code snippets, patterns, and best practices for building modern Spring Boot applications.

Tech Stack

• Java: 21+ with records and pattern matching
• Spring Boot: 4.x
• Security: JWT-based stateless authentication with Spring Security 6
• Database: JPA/Hibernate with UUID primary keys
• Build: Maven

Core Patterns Reference

This skill includes reference implementations in the assets/ directory demonstrating:

1. Base Entity Pattern (assets/entities/BaseEntity.java)

All entities should extend BaseEntity which provides:

• TIME-based UUID primary key (@UuidGenerator(style = TIME))
• Automatic timestamps (createdAt, updatedAt)
• Soft delete flag (isEnable)

@Setter
@Getter
@MappedSuperclass
@NoArgsConstructor
@AllArgsConstructor
public abstract class BaseEntity implements Serializable {
    @Id
    @UuidGenerator(style = UuidGenerator.Style.TIME)
    private String id;

    @CreationTimestamp
    private LocalDateTime createdAt;

    @UpdateTimestamp
    private LocalDateTime updatedAt;

    private boolean isEnable = true;
}

2. Response Wrapper Pattern (assets/responses/response/Response.java, assets/responses/response/PageResponse.java)

• Response<T>: Standard API response wrapper with success, data, error
• PageResponse<T>: Extends Response with pagination metadata
• Uses @SuperBuilder for inheritance with builder pattern

3. Controller Pattern (assets/controllers/UserController.java)

• @RequiredArgsConstructor for constructor injection
• ResponseEntity for proper HTTP responses
• @PreAuthorize for method-level security
• @PageableDefault for pagination defaults

4. Service Pattern (assets/services/AuthService.java)

• @Transactional(readOnly = true) at class level
• @Transactional for write methods
• Clean separation between authentication and business logic

5. Mapper Pattern (assets/mappers/UserMapper.java)

• Static utility class with private constructor
• Separate methods for different request types
• Entity <-> DTO conversion methods

6. Security Pattern (assets/security/)

• JwtTokenProvider: JWT generation and validation
• JwtAuthenticationFilter: Stateless JWT filter
• SecurityConfig: Spring Security 6 configuration with method security

7. Configuration Pattern (assets/config/)

• Type-safe @ConfigurationProperties classes
• Separate configs for CORS, JWT, etc.

When to Use This Skill

Invoke this skill when working on:

• Creating new REST endpoints
• Implementing JWT authentication
• Setting up JPA entities and repositories
• Configuring Spring Security
• Implementing pagination
• Writing service layer logic
• Creating DTOs and mappers

Code Generation

When asked to generate code, provide:

1. Code snippets for the specific pattern/component
2. Brief explanation of the pattern
3. Assets to full implementations in assets/ directory

Code Review

When reviewing Spring Boot code, check for:

• Proper use of BaseEntity for all entities
• Response wrapping with Response<T> or PageResponse<T>
• Constructor injection via @RequiredArgsConstructor
• @Transactional usage (readOnly for queries)
• Method-level security with @PreAuthorize
• Proper JWT validation in security filter

Learning Resources

For detailed examples, see:

• references/rest-api.md – REST API patterns
• references/authentication.md – JWT authentication
• references/pagination.md – Pagination patterns

For system architecture overview:

• references/architecture.md – Complete architecture documentation with diagrams and data flows

Pattern Documentation

For deep dives into specific patterns:

• references/base-entity.md
• references/response-wrapper.md
• references/controller.md
• references/service.md
• references/security.md
• references/mapper.md