Java Spring Boot

1---2name: java-spring-boot3description: Build production Spring Boot applications - REST APIs, Security, Data, Actuator4sasmp_version: "1.3.0"5version: "3.0.0"6bonded_agent: 03-java-spring7bond_type: PRIMARY_BOND8allowed-tools: Read, Write, Bash, Glob, Grep9 10# Parameter Validation11parameters:12  spring_version:13    type: string14    default: "3.2"15    description: Spring Boot version16  module:17    type: string18    enum: [web, security, data, actuator, cloud]19    description: Spring module focus20---21 22# Java Spring Boot Skill23 24Build production-ready Spring Boot applications with modern best practices.25 26## Overview27 28This skill covers Spring Boot development including REST APIs, security configuration, data access, actuator monitoring, and cloud integration. Follows Spring Boot 3.x patterns with emphasis on production readiness.29 30## When to Use This Skill31 32Use when you need to:33- Create REST APIs with Spring MVC/WebFlux34- Configure Spring Security (OAuth2, JWT)35- Set up database access with Spring Data36- Enable monitoring with Actuator37- Integrate with Spring Cloud38 39## Topics Covered40 41### Spring Boot Core42- Auto-configuration and starters43- Application properties and profiles44- Bean lifecycle and configuration45- DevTools and hot reload46 47### REST API Development48- @RestController and @RequestMapping49- Request/response handling50- Validation with Bean Validation51- Exception handling with @ControllerAdvice52 53### Spring Security54- SecurityFilterChain configuration55- OAuth2 and JWT authentication56- Method security (@PreAuthorize)57- CORS and CSRF configuration58 59### Spring Data JPA60- Repository pattern61- Query methods and @Query62- Pagination and sorting63- Auditing and transactions64 65### Actuator & Monitoring66- Health checks and probes67- Metrics with Micrometer68- Custom endpoints69- Prometheus integration70 71## Quick Reference72 73```java74// REST Controller75@RestController76@RequestMapping("/api/users")77@Validated78public class UserController {79 80    @GetMapping("/{id}")81    public ResponseEntity<User> getUser(@PathVariable Long id) {82        return userService.findById(id)83            .map(ResponseEntity::ok)84            .orElse(ResponseEntity.notFound().build());85    }86 87    @PostMapping88    public ResponseEntity<User> createUser(@Valid @RequestBody UserRequest request) {89        User user = userService.create(request);90        URI location = URI.create("/api/users/" + user.getId());91        return ResponseEntity.created(location).body(user);92    }93}94 95// Security Configuration96@Configuration97@EnableWebSecurity98public class SecurityConfig {99 100    @Bean101    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {102        return http103            .csrf(csrf -> csrf.disable())104            .sessionManagement(s -> s.sessionCreationPolicy(STATELESS))105            .authorizeHttpRequests(auth -> auth106                .requestMatchers("/actuator/health/**").permitAll()107                .requestMatchers("/api/public/**").permitAll()108                .anyRequest().authenticated())109            .oauth2ResourceServer(oauth2 -> oauth2.jwt(Customizer.withDefaults()))110            .build();111    }112}113 114// Exception Handler115@RestControllerAdvice116public class GlobalExceptionHandler {117 118    @ExceptionHandler(EntityNotFoundException.class)119    public ProblemDetail handleNotFound(EntityNotFoundException ex) {120        return ProblemDetail.forStatusAndDetail(NOT_FOUND, ex.getMessage());121    }122}123```124 125## Configuration Templates126 127```yaml128# application.yml129spring:130  application:131    name: ${APP_NAME:my-service}132  profiles:133    active: ${SPRING_PROFILES_ACTIVE:local}134  jpa:135    open-in-view: false136    properties:137      hibernate:138        jdbc.batch_size: 50139 140management:141  endpoints:142    web:143      exposure:144        include: health,info,metrics,prometheus145  endpoint:146    health:147      probes:148        enabled: true149 150server:151  error:152    include-stacktrace: never153```154 155## Common Patterns156 157### Layer Architecture158```159Controller → Service → Repository → Database160     ↓           ↓          ↓161   DTOs      Entities    Entities162```163 164### Validation Patterns165```java166public record CreateUserRequest(167    @NotBlank @Size(max = 100) String name,168    @Email @NotBlank String email,169    @NotNull @Min(18) Integer age170) {}171```172 173## Troubleshooting174 175### Common Issues176 177| Problem | Cause | Solution |178|---------|-------|----------|179| Bean not found | Missing @Component | Add annotation or @Bean |180| Circular dependency | Constructor injection | Use @Lazy or refactor |181| 401 Unauthorized | Security config | Check permitAll paths |182| Slow startup | Heavy auto-config | Exclude unused starters |183 184### Debug Properties185```properties186debug=true187logging.level.org.springframework.security=DEBUG188spring.jpa.show-sql=true189```190 191### Debug Checklist192```193□ Check /actuator/conditions194□ Verify active profiles195□ Review security filter chain196□ Check bean definitions197□ Test health endpoints198```199 200## Usage201 202```203Skill("java-spring-boot")204```205 206## Related Skills207- `java-testing` - Spring test patterns208- `java-jpa-hibernate` - Data access