1---
2name: java-spring-boot
3description: Build production Spring Boot applications - REST APIs, Security, Data, Actuator
4sasmp_version: "1.3.0"
5version: "3.0.0"
6bonded_agent: 03-java-spring
7bond_type: PRIMARY_BOND
8allowed-tools: Read, Write, Bash, Glob, Grep
9 
10# Parameter Validation
11parameters:
12  spring_version:
13    type: string
14    default: "3.2"
15    description: Spring Boot version
16  module:
17    type: string
18    enum: [web, security, data, actuator, cloud]
19    description: Spring module focus
20---
21 
22# Java Spring Boot Skill
23 
24Build production-ready Spring Boot applications with modern best practices.
25 
26## Overview
27 
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 Skill
31 
32Use when you need to:
33- Create REST APIs with Spring MVC/WebFlux
34- Configure Spring Security (OAuth2, JWT)
35- Set up database access with Spring Data
36- Enable monitoring with Actuator
37- Integrate with Spring Cloud
38 
39## Topics Covered
40 
41### Spring Boot Core
42- Auto-configuration and starters
43- Application properties and profiles
44- Bean lifecycle and configuration
45- DevTools and hot reload
46 
47### REST API Development
48- @RestController and @RequestMapping
49- Request/response handling
50- Validation with Bean Validation
51- Exception handling with @ControllerAdvice
52 
53### Spring Security
54- SecurityFilterChain configuration
55- OAuth2 and JWT authentication
56- Method security (@PreAuthorize)
57- CORS and CSRF configuration
58 
59### Spring Data JPA
60- Repository pattern
61- Query methods and @Query
62- Pagination and sorting
63- Auditing and transactions
64 
65### Actuator & Monitoring
66- Health checks and probes
67- Metrics with Micrometer
68- Custom endpoints
69- Prometheus integration
70 
71## Quick Reference
72 
73```java
74// REST Controller
75@RestController
76@RequestMapping("/api/users")
77@Validated
78public 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    @PostMapping
88    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 Configuration
96@Configuration
97@EnableWebSecurity
98public class SecurityConfig {
99 
100    @Bean
101    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
102        return http
103            .csrf(csrf -> csrf.disable())
104            .sessionManagement(s -> s.sessionCreationPolicy(STATELESS))
105            .authorizeHttpRequests(auth -> auth
106                .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 Handler
115@RestControllerAdvice
116public 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 Templates
126 
127```yaml
128# application.yml
129spring:
130  application:
131    name: ${APP_NAME:my-service}
132  profiles:
133    active: ${SPRING_PROFILES_ACTIVE:local}
134  jpa:
135    open-in-view: false
136    properties:
137      hibernate:
138        jdbc.batch_size: 50
139 
140management:
141  endpoints:
142    web:
143      exposure:
144        include: health,info,metrics,prometheus
145  endpoint:
146    health:
147      probes:
148        enabled: true
149 
150server:
151  error:
152    include-stacktrace: never
153```
154 
155## Common Patterns
156 
157### Layer Architecture
158```
159Controller → Service → Repository → Database
160     ↓           ↓          ↓
161   DTOs      Entities    Entities
162```
163 
164### Validation Patterns
165```java
166public record CreateUserRequest(
167    @NotBlank @Size(max = 100) String name,
168    @Email @NotBlank String email,
169    @NotNull @Min(18) Integer age
170) {}
171```
172 
173## Troubleshooting
174 
175### Common Issues
176 
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 Properties
185```properties
186debug=true
187logging.level.org.springframework.security=DEBUG
188spring.jpa.show-sql=true
189```
190 
191### Debug Checklist
192```
193□ Check /actuator/conditions
194□ Verify active profiles
195□ Review security filter chain
196□ Check bean definitions
197□ Test health endpoints
198```
199 
200## Usage
201 
202```
203Skill("java-spring-boot")
204```
205 
206## Related Skills
207- `java-testing` - Spring test patterns
208- `java-jpa-hibernate` - Data access
209