Spring Boot
Mastery
Build production-ready Java applications with the most powerful framework. From REST APIs to microservices, master every concept with real examples.
Everything you need
to build modern applications
Spring Boot makes it easy to create production-grade Spring-based applications that you can "just run" with minimal configuration.
Click any card to explore the concept, see examples, and test your knowledge.
Get started in minutes
Follow these simple steps to create and run your first Spring Boot application.
01# Using Spring Boot CLI02spring init --dependencies=web,data-jpa,h2 myapp0304# Or using Maven05mvn archetype:generate \06 -DgroupId=com.example \07 -DartifactId=myapp \08 -DarchetypeArtifactId=maven-archetype-quickstartCore Concepts
Master the fundamental building blocks of Spring Boot applications
Inversion of Control (IoC)
The Foundation of Spring
IoC is a design principle where the control of object creation and lifecycle is transferred from the application code to the Spring container. Instead of your code creating dependencies, Spring injects them automatically.
Key Points
01// Traditional approach (tight coupling)02public class OrderService {03 private PaymentService paymentService = new PaymentService();04}0506// IoC approach (loose coupling)07@Service08public class OrderService {09 private final PaymentService paymentService;10 11 @Autowired12 public OrderService(PaymentService paymentService) {13 this.paymentService = paymentService;14 }15}Supported AI Providers
Key Capabilities
Quick Start Configuration
Maven Dependencies
<dependency>
<groupId>org.springframework.ai</groupId>
<artifactId>spring-ai-openai-spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.ai</groupId>
<artifactId>spring-ai-pgvector-store-spring-boot-starter</artifactId>
</dependency>Application Properties
# OpenAI Configuration
spring.ai.openai.api-key=${OPENAI_API_KEY}
spring.ai.openai.chat.options.model=gpt-4
spring.ai.openai.chat.options.temperature=0.7
# Vector Store (PGVector)
spring.ai.vectorstore.pgvector.index-type=HNSW
spring.ai.vectorstore.pgvector.distance-type=COSINE_DISTANCE
spring.ai.vectorstore.pgvector.dimensions=1536
# Embedding Model
spring.ai.openai.embedding.options.model=text-embedding-3-smallComplete Code Examples
Basic Chat Client
Simple chat interaction with any supported AI model
@RestController
@RequestMapping("/api/chat")
public class ChatController {
private final ChatClient chatClient;
public ChatController(ChatClient.Builder builder) {
this.chatClient = builder
.defaultSystem("You are a helpful assistant.")
.build();
}
@PostMapping
public String chat(@RequestBody String message) {
return chatClient.prompt()
.user(message)
.call()
.content();
}
// Streaming response for real-time chat
@GetMapping(value = "/stream", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
public Flux<String> streamChat(@RequestParam String message) {
return chatClient.prompt()
.user(message)
.stream()
.content();
}
}Supported Vector Stores
Easily switch between vector stores without changing your application code
Spring AI Architecture
Your Application
Controllers, Services, Business Logic
Spring AI
Unified API, Advisors, Memory
AI Providers
OpenAI, Anthropic, Google, AWS...
Best Practices
Learn by building
Complete, production-ready code examples you can use as a starting point for your projects.
REST API with CRUD Operations
Complete REST API example with all HTTP methods, validation, and error handling
001package com.example.demo.model;002003import jakarta.persistence.*;004import jakarta.validation.constraints.*;005import java.math.BigDecimal;006import java.time.LocalDateTime;007008@Entity009@Table(name = "products")010public class Product {011 012 @Id013 @GeneratedValue(strategy = GenerationType.IDENTITY)014 private Long id;015 016 @NotBlank(message = "Name is required")017 @Size(min = 2, max = 100)018 private String name;019 020 @Size(max = 500)021 private String description;022 023 @NotNull(message = "Price is required")024 @DecimalMin(value = "0.0", inclusive = false)025 private BigDecimal price;026 027 @Min(0)028 private Integer quantity = 0;029 030 @Column(name = "created_at")031 private LocalDateTime createdAt;032 033 @Column(name = "updated_at")034 private LocalDateTime updatedAt;035 036 @PrePersist037 protected void onCreate() {038 createdAt = LocalDateTime.now();039 updatedAt = LocalDateTime.now();040 }041 042 @PreUpdate043 protected void onUpdate() {044 updatedAt = LocalDateTime.now();045 }046 047 // Getters and Setters...048}Layered Architecture
Spring Boot applications follow a layered architecture pattern that promotes separation of concerns, testability, and maintainability.
Application Layers
Presentation Layer
Layer 1Handles HTTP requests, input validation, and response formatting
Service Layer
Layer 2Contains business logic, orchestrates operations, manages transactions
Repository Layer
Layer 3Handles data persistence, database queries, and entity management
Database Layer
Layer 4Actual data storage, indexing, and data integrity
Recommended Project Structure
Why This Structure?
- • Separation of concerns - Each package has a clear responsibility
- • Easy navigation - Find code quickly by type or domain
- • Testability - Mock dependencies at layer boundaries
- • Scalability - Add features without restructuring