🚀 Complete Spring Boot Learning Plan

📅 Duration: 8 Weeks | 🎯 Level: Beginner to Advanced | 🏆 Goal: Production-Ready Developer

🛠️ Technology Stack Covered

Core: Spring Boot, Spring Framework, Java
Database: PostgreSQL, JPA/Hibernate
Security: Spring Security, JWT Authentication
Architecture: RESTful APIs, Microservices patterns
Tools: Maven/Gradle, Docker, Testing frameworks

📚 Week 1: Foundation & Setup

🎯 Learning Objectives

Understand Spring Boot fundamentals and ecosystem
Set up development environment
Learn Spring Boot lifecycle and auto-configuration
Create your first Spring Boot application

✅ Daily Tasks

Day 1-2: Install JDK 17+, IntelliJ IDEA/Eclipse, Maven/Gradle
Day 3: Study Spring Boot architecture and lifecycle
Day 4: Create first app using Spring Initializr
Day 5: Explore auto-configuration and application properties
Day 6-7: Practice with different Spring Boot starters

🎨 Mini Project: Hello World Service

Create a simple REST endpoint that returns system information
Add custom application properties
Implement different profiles (dev, test, prod)
Add actuator for health checks

📝 Week 1 Assessment

Quiz on Spring Boot lifecycle and auto-configuration
Code review of Hello World Service project
Demonstration of profile switching

🗄️ Week 2: Database Integration & JPA

🎯 Learning Objectives

Set up PostgreSQL database
Master JPA/Hibernate concepts
Implement entity relationships
Learn repository patterns

✅ Daily Tasks

Day 1: Install PostgreSQL, create database schema
Day 2: Configure Spring Data JPA
Day 3: Create entities with annotations
Day 4: Implement repository interfaces
Day 5: Practice JPQL and native queries
Day 6-7: Handle entity relationships (OneToMany, ManyToMany)

🎨 Project: Library Management System

Entities: Book, Author, Category, User
Relationships: Author-Book (OneToMany), Book-Category (ManyToMany)
Repository methods with custom queries
Database migrations with Flyway/Liquibase

@Entity
public class Book {
    @Id @GeneratedValue
    private Long id;
    private String title;
    @ManyToOne
    private Author author;
    // ... other fields and methods
}
                

📝 Week 2 Assessment

Database design evaluation
JPA query performance analysis
Code review of repository implementations

🌐 Week 3: RESTful APIs & Web Layer

🎯 Learning Objectives

Master REST principles and HTTP methods
Implement comprehensive CRUD operations
Handle request/response mapping
Implement proper error handling

✅ Daily Tasks

Day 1: Study REST principles and HTTP status codes
Day 2: Create controller classes with @RestController
Day 3: Implement CRUD endpoints
Day 4: Add request validation and DTOs
Day 5: Implement global exception handling
Day 6-7: Add pagination, sorting, and filtering

🎨 Project: E-commerce Product API

Complete CRUD for Products, Categories, and Reviews
Search functionality with filters
Pagination and sorting implementation
Custom exception handling with proper HTTP responses
Input validation with Bean Validation

@RestController
@RequestMapping("/api/products")
public class ProductController {
    
    @GetMapping
    public ResponseEntity<Page<ProductDTO>> getAllProducts(
            @PageableDefault(size = 20) Pageable pageable,
            @RequestParam(required = false) String category) {
        // Implementation
    }
    
    @PostMapping
    @Valid
    public ResponseEntity<ProductDTO> createProduct(@RequestBody ProductCreateDTO dto) {
        // Implementation
    }
}
                

📝 Week 3 Assessment

API design evaluation using REST principles
Error handling implementation review
Performance testing of endpoints

🔒 Week 4: Security & JWT Implementation

🎯 Learning Objectives

Implement Spring Security fundamentals
Set up JWT-based authentication
Configure role-based access control
Secure REST endpoints

✅ Daily Tasks

Day 1: Study Spring Security architecture
Day 2: Implement user authentication with database
Day 3: Configure JWT token generation and validation
Day 4: Set up role-based authorization
Day 5: Implement login/logout endpoints
Day 6-7: Secure existing APIs and handle CORS

🎨 Project: Secure User Management System

User registration and login with JWT
Role-based access (USER, ADMIN, MODERATOR)
Password encryption with BCrypt
JWT refresh token implementation
Security for all previous API endpoints

@Configuration
@EnableWebSecurity
public class SecurityConfig {
    
    @Bean
    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
        return http
            .authorizeHttpRequests(auth -> auth
                .requestMatchers("/api/auth/**").permitAll()
                .requestMatchers("/api/admin/**").hasRole("ADMIN")
                .anyRequest().authenticated())
            .sessionManagement(session -> session
                .sessionCreationPolicy(SessionCreationPolicy.STATELESS))
            .addFilterBefore(jwtAuthFilter, UsernamePasswordAuthenticationFilter.class)
            .build();
    }
}
                

📝 Week 4 Assessment

Security configuration review
JWT implementation testing
Authorization scenarios validation

⚡ Week 5: Performance Optimization & Advanced JPA

🎯 Learning Objectives

Optimize database queries and JPA performance
Implement caching strategies
Handle N+1 query problems
Monitor application performance

✅ Daily Tasks

Day 1: Learn JPA fetch strategies and lazy loading
Day 2: Implement query optimization techniques
Day 3: Set up Redis caching
Day 4: Configure application-level caching
Day 5: Add database connection pooling
Day 6-7: Performance monitoring and profiling

🎨 Project: High-Performance Blog API

Optimized blog post queries with pagination
Implement Redis caching for popular posts
Database indexing for search functionality
Connection pooling with HikariCP
Performance metrics with Micrometer

@Entity
public class BlogPost {
    @Id @GeneratedValue
    private Long id;
    
    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "author_id")
    private User author;
    
    @OneToMany(mappedBy = "post", fetch = FetchType.LAZY)
    @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
    private List<Comment> comments;
}

@Cacheable(value = "popularPosts")
public List<BlogPost> getPopularPosts() {
    return blogPostRepository.findTop10ByOrderByViewCountDesc();
}
                

📝 Week 5 Assessment

Performance benchmarking results
Caching strategy effectiveness analysis
Query optimization review

🧪 Week 6: Testing & Quality Assurance

🎯 Learning Objectives

Master unit testing with JUnit and Mockito
Implement integration testing
Test REST APIs and security
Set up continuous testing practices

✅ Daily Tasks

Day 1: Write unit tests for service layer
Day 2: Test repository layer with @DataJpaTest
Day 3: Integration tests with @SpringBootTest
Day 4: Test REST APIs with MockMvc
Day 5: Security testing and authentication flows
Day 6-7: Test coverage analysis and test containers

🎨 Project: Comprehensive Test Suite

Unit tests for all service methods
Integration tests for API endpoints
Security testing for protected resources
Database testing with Testcontainers
Achieve 80%+ code coverage

@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
@Testcontainers
class ProductControllerIntegrationTest {
    
    @Container
    static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>("postgres:13")
            .withDatabaseName("testdb")
            .withUsername("test")
            .withPassword("test");
    
    @Test
    @WithMockUser(roles = "ADMIN")
    void shouldCreateProduct() throws Exception {
        mockMvc.perform(post("/api/products")
                .contentType(MediaType.APPLICATION_JSON)
                .content(objectMapper.writeValueAsString(productDto)))
                .andExpect(status().isCreated())
                .andExpect(jsonPath("$.name").value("Test Product"));
    }
}
                

📝 Week 6 Assessment

Test coverage report analysis
Code quality metrics review
Testing strategy presentation

🏗️ Week 7: Advanced Architecture & Microservices

🎯 Learning Objectives

Implement microservices patterns
Set up service discovery and configuration
Handle inter-service communication
Implement circuit breaker patterns

✅ Daily Tasks

Day 1: Study microservices architecture principles
Day 2: Split monolith into multiple services
Day 3: Implement service-to-service communication
Day 4: Set up API Gateway pattern
Day 5: Implement circuit breaker with Resilience4j
Day 6-7: Add distributed tracing and monitoring

🎨 Project: E-commerce Microservices

User Service (authentication, profiles)
Product Service (catalog, inventory)
Order Service (order processing, payments)
API Gateway with Spring Cloud Gateway
Service discovery with Eureka
Circuit breakers for resilience

@RestController
public class OrderController {
    
    @Autowired
    private ProductServiceClient productService;
    
    @CircuitBreaker(name = "product-service", fallbackMethod = "fallbackGetProduct")
    @GetMapping("/orders/{id}/products")
    public ResponseEntity<List<Product>> getOrderProducts(@PathVariable Long id) {
        return productService.getProductsByOrderId(id);
    }
    
    public ResponseEntity<List<Product>> fallbackGetProduct(Long id, Exception ex) {
        return ResponseEntity.ok(Collections.emptyList());
    }
}
                

📝 Week 7 Assessment

Microservices architecture review
Service communication evaluation
Resilience patterns demonstration

🚀 Week 8: Deployment & Production Readiness

🎯 Learning Objectives

Containerize applications with Docker
Set up production configurations
Implement monitoring and logging
Deploy to cloud platforms

✅ Daily Tasks

Day 1: Create Docker images for services
Day 2: Set up Docker Compose for local development
Day 3: Configure production profiles and externalized config
Day 4: Implement comprehensive logging with Logback
Day 5: Set up monitoring with Prometheus and Grafana
Day 6-7: Deploy to cloud platform (AWS/GCP/Azure)

🎨 Final Project: Production-Ready E-commerce Platform

Complete microservices architecture
Docker containerization
CI/CD pipeline setup
Production monitoring and alerting
Load balancing and auto-scaling
Database backup and recovery strategy

# Dockerfile
FROM openjdk:17-jdk-slim
VOLUME /tmp
COPY target/product-service-1.0.jar app.jar
ENTRYPOINT ["java","-jar","/app.jar"]

# docker-compose.yml
version: '3.8'
services:
  product-service:
    build: ./product-service
    ports:
      - "8081:8081"
    environment:
      - SPRING_PROFILES_ACTIVE=docker
    depends_on:
      - postgres
      - redis
                

📝 Final Assessment

Complete system architecture presentation
Production deployment demonstration
Performance and security audit
Code quality and best practices review

🏆 Graduation Requirements

Portfolio Projects: All 8 projects completed and deployed
Code Quality: 80%+ test coverage, clean code principles
Performance: Sub-200ms API response times under load
Security: Complete JWT implementation with role-based access
Production: Deployed microservices with monitoring

📚 Additional Resources & Best Practices

📖 Recommended Reading

Spring Boot in Action by Craig Walls
Spring Security in Action by Laurentiu Spilca
Microservices Patterns by Chris Richardson
Java Performance: In-Depth Advice by Scott Oaks

🛠️ Tools & Platforms

IDE: IntelliJ IDEA Ultimate or VS Code with extensions
Database: PostgreSQL 13+, pgAdmin for management
Caching: Redis 6+
Monitoring: Prometheus, Grafana, ELK Stack
Testing: JUnit 5, Mockito, Testcontainers
Documentation: Swagger/OpenAPI 3

🔧 Development Best Practices

Follow SOLID principles and clean architecture
Implement comprehensive error handling and logging
Use DTOs for API layer separation
Apply database migrations for schema changes
Implement proper security headers and CORS configuration
Use connection pooling and optimize database queries
Implement graceful shutdown and health checks

🎯 Upon completion, you'll be ready for Spring Boot developer roles and have a portfolio showcasing production-ready applications!