asmhatre
baff043748
- naive @SchemaMapping resolver: 6 statements (5 books/5 authors), 21 statements (20 books/5 authors) - batched @BatchMapping resolver: flat 2 statements in both cases, via DataLoader + .distinct() - dangling authorId nulls the entire GraphQL response via non-null propagation, byte-identical under both resolver strategies - 6-test suite over real HTTP against a live embedded Tomcat instance, SQL captured via a JDK dynamic proxy (StatementLoggingDataSource, reused from sdjpa4-demo) - docs/05: two Boot 4.1 packaging changes hit along the way (DataSourceAutoConfiguration's new package, Jackson 3 by default) - root README: add row for graphql-dataloader; fix openapi-versioning's placeholder link now that post 7477 is live
48 lines
7.0 KiB
Markdown
48 lines
7.0 KiB
Markdown
# spring-boot-demo
|
|
|
|
Companion code for the Spring Boot articles on **[ankurm.com](https://ankurm.com)**.
|
|
|
|
One directory per article. Each is a self-contained Maven project with its own `README.md`,
|
|
numbered documentation chapters under `docs/`, and captured real output under `docs/output/`
|
|
that a single script regenerates. Every figure quoted in an article came out of one of those
|
|
files.
|
|
|
|
| Directory | Article | What it demonstrates |
|
|
|---|---|---|
|
|
| [`actuator-in-production/`](actuator-in-production) | [Spring Boot Actuator in Production](https://ankurm.com/spring-boot-actuator-production-endpoints-security-health-indicators/) | endpoint exposure defaults, securing Actuator, custom health indicators and how they hang |
|
|
| [`spring-boot-startup-time/`](spring-boot-startup-time) | [Why Your Spring Boot App Takes 8 Seconds to Start](spring-boot-startup-time/post/post.md) | `BufferingApplicationStartup`, JFR startup events, self time vs total time, the classpath-scan tax, the JDK 25 AOT cache |
|
|
| [`configuration-properties/`](configuration-properties) | [@ConfigurationProperties vs @Value in Spring Boot 4](https://ankurm.com/) | relaxed binding measured three ways, record constructor binding, validation, IDE metadata generation |
|
|
| [`profiles-and-config/`](profiles-and-config) | [Spring Boot Profiles Done Right](https://ankurm.com/) | the precedence stack made visible, config trees and ConfigMaps, why a profile file loses to an environment variable |
|
|
| [`spring-aop/`](spring-aop) | [Spring AOP Explained](https://ankurm.com/) | every pointcut designator with real matches, JDK vs CGLIB proxies, six aspects that do not fire |
|
|
| [`docker-images/`](docker-images) | [Dockerizing Spring Boot 4: Layered Jars, Buildpacks, Distroless and Image Size Benchmarks](https://ankurm.com/dockerizing-spring-boot-4-layered-jars-buildpacks-distroless/) | one service packaged nine ways and measured: size on disk and pushed, rebuild delta, startup, PID 1 and signals, jlink, the JDK 25 AOT cache |
|
|
| [`kubernetes-deployment/`](kubernetes-deployment) | [Deploying Spring Boot 4 on Kubernetes](https://ankurm.com/spring-boot-4-kubernetes-probes-graceful-shutdown-cpu-limits-hpa/) | probe groups under a dependency outage, graceful shutdown under load four ways, JVM ergonomics per pod shape, CPU limits throttling GC, HPA on a Micrometer metric |
|
|
| [`problem-details/`](problem-details) | [Global Exception Handling with ProblemDetail (RFC 9457) in Spring Boot 4](https://ankurm.com/spring-boot-4-problemdetail-rfc-9457-global-exception-handling/) | thirteen failures under five handling setups, validation errors, i18n, content negotiation, errors outside MVC, silent 500s, decoding on the client |
|
|
| [`resilience/`](resilience) | [Spring Framework 7's Built-in Resilience: @Retryable, @ConcurrencyLimit, and What's Left for Resilience4j](https://ankurm.com/spring-framework-7-retryable-concurrencylimit-resilience4j/) | `@Retryable` and `@ConcurrencyLimit` counted invocation by invocation, retries inside transactions, where Resilience4j still earns its place, migrating from Spring Retry |
|
|
| [`caching/`](caching) | [The Spring Cache Abstraction: @Cacheable, @CacheEvict, Key Generators and the Self-Invocation Trap](https://ankurm.com/spring-cache-abstraction-cacheable-cacheevict-self-invocation-trap/) | the self-invocation trap measured four ways, the key collision `SimpleKeyGenerator` makes easy, eviction timing under a thrown exception, a rollback the cache keeps, and where this sits next to Hibernate's L2 cache |
|
|
| [`spring-batch/`](spring-batch) | [Spring Batch on Boot 4.1: Jobs, Steps, Chunk Processing and Restartability](https://ankurm.com/) | a job that fails mid-chunk and resumes exactly where it left off across two separate JVMs, skip vs. restart on the same poisoned row, the resourceless job repository that forgets a restart ever happened, and the `chunk(int)` vs `chunk(int, tx)` builder split |
|
|
| [`spring-batch-partitioning/`](spring-batch-partitioning) | [Spring Batch Partitioning and Parallel Steps: Scaling a 10-Million-Row Job](https://ankurm.com/) | the real grid-size sweep at 10M and 300K rows (best speedup 1.42x, on 2 cores), `MultiResourcePartitioner` ignoring gridSize entirely, a rejected partition's `StepExecution` stuck at `STARTING` forever, and Spring Batch 6.0's new `JobOperator#recover` unsticking it |
|
|
| [`db-migrations-flyway-liquibase/`](db-migrations-flyway-liquibase) | [Flyway vs Liquibase for Spring Boot 4: Migrations, Rollbacks and Baselines](https://ankurm.com/flyway-vs-liquibase-spring-boot-4-migrations-rollbacks-baselines/) | Flyway Community's `undo` throwing `FlywayRedgateEditionRequiredException` at runtime, a real Liquibase 5.0.3 filename-caching defect that produces a phantom successful run, Liquibase's 10-second default lock-poll rate versus Flyway's near-instant row lock, the FSL license change and its ASF/Keycloak fallout, and what actually happens when both tools are enabled against one database |
|
|
| [`db-migrations-expand-contract/`](db-migrations-expand-contract) | [Zero-Downtime Database Migrations: Expand-Contract in Practice with Spring Boot](https://ankurm.com/zero-downtime-database-migrations-expand-contract-spring-boot/) | a real 4-deploy rolling sequence against two live replicas with a load generator proving 99.98% success, H2's `AUTO_SERVER` single-point-of-failure trap, a `NOT NULL` constraint that fails every Stage 4 insert, and `ALTER TABLE` silently dropping a concurrently committed row with no exception thrown |
|
|
| [`openapi-versioning/`](openapi-versioning) | [springdoc-openapi with Spring Boot 4.1: Generating, Customising and Versioning Your API Spec](https://ankurm.com/springdoc-openapi-spring-boot-4-1-versioning/) | springdoc 3.1.1 silently merging same-path, different-version handlers into one `oneOf` operation with an arbitrary `operationId`, a working per-version fix with `GroupedOpenApi` + `OpenApiCustomizer`, and the officially-versioning-supported functional-endpoint path turning out to document only one of two registered versions |
|
|
| [`graphql-dataloader/`](graphql-dataloader) | [Spring GraphQL 2.0: Schema-First APIs, DataLoader Batching and Killing N+1](https://ankurm.com/) | a naive `@SchemaMapping` resolver measured at 21 SQL statements for 20 books versus a `@BatchMapping` resolver's flat 2, a dangling foreign key nulling an entire GraphQL response via non-null propagation identically under both resolver strategies, and two Spring Boot 4.1 packaging changes (`DataSourceAutoConfiguration`'s new package, Jackson 3 by default) hit along the way |
|
|
|
|
Articles whose text is kept here rather than only on the blog have it under
|
|
`<directory>/post/` — `post.md` for the body and `meta.md` for the title, excerpt and
|
|
categories.
|
|
|
|
## Running any of them
|
|
|
|
Each project needs a JDK 25 and Maven 3.9. `docker-images` also needs Docker, and
|
|
`kubernetes-deployment` Docker plus a Kubernetes cluster; their READMEs list the rest:
|
|
|
|
```bash
|
|
cd <directory>
|
|
export JAVA_HOME=/path/to/jdk-25
|
|
mvn -DskipTests package
|
|
./scripts/run-all.sh # regenerate every transcript under docs/output/
|
|
```
|
|
|
|
## Licence
|
|
|
|
MIT — see [LICENSE](LICENSE).
|