java-spring-boot
# Java Spring Boot Skill
Build production-ready Spring Boot applications with modern best practices.
## Overview
This 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.
## When to Use This Skill
Use when you need to:
- Create REST APIs with Spring MVC/WebFlux
- Configure Spring Security (OAuth2, JWT)
- Set up database access with Spring Data
- Enable monitoring with Actuator
- Integrate with Spring Cloud
## Topics Covered
### Spring Boot Core
- Auto-configuration and starters
- Application properties and profiles
- Bean lifecycle and configuration
- DevTools and hot reload
### REST API Development
- @RestController and @RequestMapping
- Request/response handling
- Validation with Bean Validation
- Exception handling with @ControllerAdvice
### Spring Security
- SecurityFilterChain configuration
- OAuth2 and JWT authentication
- Method security (@PreAuthorize)
- CORS and CSRF configuration
### Spring Data JPA
- Repository pattern
- Query methods and @Query
- Pagination and sorting
- Auditing and transactions
### Actuator & Monitoring
- Health checks and probes
- Metrics with Micrometer
- Custom endpoints
- Prometheus integration
## Quick Reference
```java
// REST Controller
@RestController
@RequestMapping("/api/users")
@Validated
public class UserController {
@GetMapping("/{id}")
public ResponseEntity<User> getUser(@PathVariable Long id) {
return userService.findById(id)
.map(ResponseEntity::ok)
.orElse(ResponseEntity.notFound().build());
}
@PostMapping
public ResponseEntity<User> createUser(@Valid @RequestBody UserRequest request) {
User user = userService.create(request);
URI location = URI.create("/api/users/" + user.getId());
return ResponseEntity.created(location).body(user);
}
}
// Security Configuration
@Configuration
@EnableWebSecurity
public class SecurityConfig {
@Bean
public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
return http
.csrf(csrf -> csrf.disable())
.sessionManagement(s -> s.sessionCreationPolicy(STATELESS))
.authorizeHttpRequests(auth -> auth
.requestMatchers("/actuator/health/**").permitAll()
.requestMatchers("/api/public/**").permitAll()
.anyRequest().authenticated())
.oauth2ResourceServer(oauth2 -> oauth2.jwt(Customizer.withDefaults()))
.build();
}
}
// Exception Handler
@RestControllerAdvice
public class GlobalExceptionHandler {
@ExceptionHandler(EntityNotFoundException.class)
public ProblemDetail handleNotFound(EntityNotFoundException ex) {
return ProblemDetail.forStatusAndDetail(NOT_FOUND, ex.getMessage());
}
}
```
## Configuration Templates
```yaml
# application.yml
spring:
application:
name: ${APP_NAME:my-service}
profiles:
active: ${SPRING_PROFILES_ACTIVE:local}
jpa:
open-in-view: false
properties:
hibernate:
jdbc.batch_size: 50
management:
endpoints:
web:
exposure:
include: health,info,metrics,prometheus
endpoint:
health:
probes:
enabled: true
server:
error:
include-stacktrace: never
```
## Common Patterns
### Layer Architecture
```
Controller → Service → Repository → Database
↓ ↓ ↓
DTOs Entities Entities
```
### Validation Patterns
```java
public record CreateUserRequest(
@NotBlank @Size(max = 100) String name,
@Email @NotBlank String email,
@NotNull @Min(18) Integer age
) {}
```
## Troubleshooting
### Common Issues
| Problem | Cause | Solution |
|---------|-------|----------|
| Bean not found | Missing @Component | Add annotation or @Bean |
| Circular dependency | Constructor injection | Use @Lazy or refactor |
| 401 Unauthorized | Security config | Check permitAll paths |
| Slow startup | Heavy auto-config | Exclude unused starters |
### Debug Properties
```properties
debug=true
logging.level.org.springframework.security=DEBUG
spring.jpa.show-sql=true
```
### Debug Checklist
```
□ Check /actuator/conditions
□ Verify active profiles
□ Review security filter chain
□ Check bean definitions
□ Test health endpoints
```
## Usage
```
Skill("java-spring-boot")
```
## Related Skills
- `java-testing` - Spring test patterns
- `java-jpa-hibernate` - Data access
标签
skill
ai
