Java
@RestController
@RequestMapping("/api/users")
public class UserController {
    
    @Autowired
    private UserService userService;
    
    @GetMapping
    public ResponseEntity<List<User>> getUsers() {
        return ResponseEntity.ok(userService.findAll());
    }
    
    @PostMapping
    public ResponseEntity<User> createUser(@Valid @RequestBody CreateUserRequest request) {
        User user = userService.create(request);
        return ResponseEntity.status(HttpStatus.CREATED).body(user);
    }
}

Progress:

• Analyze requirements and design API contracts
• Set up Spring Boot project with required dependencies
• Implement domain models and repositories
• Create service layer with business logic
• Build REST controllers with proper validation
• Add security configuration (JWT/OAuth2)
• Write comprehensive tests (unit + integration)
• Set up database migrations and configurations
• Implement Angular frontend components
• Configure CI/CD pipeline

Spring Boot Project Structure

src/
├── main/
│   ├── java/
│   │   └── com/company/app/
│   │       ├── config/        # Security, DB config
│   │       ├── controller/    # REST endpoints
│   │       ├── dto/          # Request/Response objects
│   │       ├── entity/       # JPA entities
│   │       ├── repository/   # Data access
│   │       ├── service/      # Business logic
│   │       └── exception/    # Custom exceptions
│   └── resources/
│       ├── application.yml
│       └── db/migration/     # Flyway scripts
└── test/
    └── java/                 # Unit & integration tests

Example 1: Service Layer Implementation Input: User management requirements Output:

Java
@Service
@Transactional
public class UserService {
    
    private final UserRepository userRepository;
    private final PasswordEncoder passwordEncoder;
    
    public UserService(UserRepository userRepository, PasswordEncoder passwordEncoder) {
        this.userRepository = userRepository;
        this.passwordEncoder = passwordEncoder;
    }
    
    public User create(CreateUserRequest request) {
        if (userRepository.existsByEmail(request.getEmail())) {
            throw new UserAlreadyExistsException("Email already registered");
        }
        
        User user = User.builder()
            .email(request.getEmail())
            .password(passwordEncoder.encode(request.getPassword()))
            .role(UserRole.USER)
            .createdAt(Instant.now())
            .build();
            
        return userRepository.save(user);
    }
}

Example 2: Security Configuration Input: JWT authentication requirements Output:

Java
@Configuration
@EnableWebSecurity
@EnableMethodSecurity
public class SecurityConfig {
    
    @Bean
    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
        return http
            .csrf(csrf -> csrf.disable())
            .sessionManagement(session -> session.sessionCreationPolicy(STATELESS))
            .authorizeHttpRequests(auth -> auth
                .requestMatchers("/api/auth/**").permitAll()
                .requestMatchers(HttpMethod.GET, "/api/users").hasRole("ADMIN")
                .anyRequest().authenticated())
            .oauth2ResourceServer(oauth2 -> oauth2.jwt(Customizer.withDefaults()))
            .build();
    }
}

Example 3: Integration Test Input: User API testing requirements Output:

Java
@SpringBootTest(webEnvironment = RANDOM_PORT)
@Testcontainers
class UserControllerIntegrationTest {
    
    @Container
    static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>("postgres:15");
    
    @Autowired
    private TestRestTemplate restTemplate;
    
    @Test
    void shouldCreateUserSuccessfully() {
        CreateUserRequest request = new CreateUserRequest("test@example.com", "password123");
        
        ResponseEntity<User> response = restTemplate.postForEntity("/api/users", request, User.class);
        
        assertThat(response.getStatusCode()).isEqualTo(HttpStatus.CREATED);
        assertThat(response.getBody().getEmail()).isEqualTo("test@example.com");
    }
}