Spring code explainers

java

@Component
@Converter
public class EncryptedStringConverter implements AttributeConverter<String, String> {

Transparent column encryption in Spring & JPA

encryption aes-gcm jpa-converter

Advanced 10 steps

java

package com.acme.billing.config;
 
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.context.properties.ConfigurationProperties;

Feature-flagged beans with Spring @ConditionalOnProperty

feature-flags conditional-beans strategy-pattern

Intermediate 5 steps

java

package com.example.api.config;
 
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;

Configuring CORS in Spring MVC

cors configuration dependency-injection

Intermediate 6 steps

java

@Configuration
public class PaymentGatewayClientConfig {
 
    @Bean

Building a resilient RestClient in Spring

retry http-client backoff

Intermediate 9 steps

java

@Service
public class ProductLookupService {
 
    private final ProductRepository productRepository;

How Spring caching layers a product lookup

caching cache-eviction fallback

Intermediate 8 steps

java

package com.example.actuator;
 
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.actuate.endpoint.annotation.Endpoint;

Building a custom Spring Boot Actuator endpoint

actuator dependency-injection observability

Intermediate 7 steps

java

@Configuration
public class ValidationConfig implements WebMvcConfigurer {
 
    @Bean

Localized bean validation messages in Spring

internationalization bean-validation configuration

Intermediate 6 steps

java

@Controller
@RequestMapping("/employees")
public class EmployeeController {

Building a Spring MVC form controller

mvc form-handling validation

Intermediate 8 steps

java

@Component
public class ApiKeyRotationFilter extends OncePerRequestFilter {
 
    private static final String API_KEY_HEADER = "X-Api-Key";

Building an API key rotation filter in Spring

servlet-filter authentication caching

Intermediate 10 steps

java

@Configuration
@EnableJpaAuditing(auditorAwareRef = "auditorAware")
public class AuditingConfig {

Automatic audit trails with Spring Data JPA

jpa-auditing security-context entity-listeners

Intermediate 7 steps

java

@Service
public class WebhookDedupService {
 
    private static final Logger log = LoggerFactory.getLogger(WebhookDedupService.class);

Idempotent webhooks with Redis in Spring

idempotency redis deduplication

Intermediate 7 steps

java

@Component
public class IdempotencyFilter extends OncePerRequestFilter {
 
    private final StringRedisTemplate redis;

Building an idempotency filter with Redis in Spring

idempotency redis distributed-locking

Advanced 10 steps

java

@Configuration
public class DataLoaderConfig {
 
    @Bean

Batching GraphQL queries with DataLoaders in Spring

graphql batching n+1-problem

Advanced 8 steps

java

public enum DataSourceType {
    PRIMARY,
    REPLICA
}

Read/write datasource routing in Spring

routing threadlocal read-replica

Intermediate 8 steps

java

@ControllerAdvice
public class DeprecationHeaderAdvice implements ResponseBodyAdvice<Object> {
 
    private final Clock clock;

Adding deprecation headers in Spring

response interception http headers api deprecation

Intermediate 8 steps

java

@Component
@RequiredArgsConstructor
@Slf4j
public class FailedJobReprocessor {

Retrying failed jobs on a Spring schedule

scheduling retry exponential-backoff

Intermediate 10 steps

java

public class Views {
    public interface Public {}
    public interface Internal extends Public {}
}

Filtering JSON fields with @JsonView in Spring

serialization json-view access-control

Intermediate 6 steps

java

@Configuration
public class WebConfig {
 
    @Bean

HTTP caching with ETags in Spring

http-caching etag servlet-filters

Intermediate 6 steps