JCarranza Mini-Midoffice

A travel-agency mid-office system — and a hands-on record of migrating it from Spring 5.3 → 6.1 / Hibernate 5.6 → 6.4 / Tomcat 9 → 10.1, commit by commit, every step compiling green.

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Spring 5→6 / Hibernate 5→6 Migration

	v1.0 — before	v2.0 — after
Spring Framework	5.3.39	6.1.14
Hibernate ORM	5.6.15.Final	6.4.4.Final
Servlet container	Tomcat 9	Tomcat 10.1
Namespace	javax.*	jakarta.*
Transaction manager	HibernateTransactionManager	JpaTransactionManager

Steps 0–4 were committed as isolated, always-green changesets. Ten gotchas are documented in docs/10-migration-spring6.md — including the non-obvious ones: Spring 6 ships no hibernate6 ORM package (forcing the full JPA-based config), the -parameters compiler flag requirement, and why the transaction manager change is behaviourally equivalent for this codebase.

Full migration write-up → · v1.0 → v2.0 diff →

This is a technical exercise documenting how the migration is approached and recorded — not a recommendation about what any production system should do.

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Sabre GDS Integration

Live integration with the Sabre certification sandbox: OAuth2 client-credentials, flight search (POST /v1/offers/flightSearch), real-time FlightCheck price verification (POST /v1/offers/flightCheck), and booking reserve. Behind a port/adapter anti-corruption layer — the GdsFlightSearchPort and GdsFlightCheckPort interfaces mean Sabre can be swapped for Amadeus or Galileo without touching the service layer.

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What It Demonstrates

• Maven multi-module WAR — five modules (domain / integration / persistence / service / web), no Spring Boot
• Explicit two-context Spring setup — Root context (services, DAOs, Hibernate) separate from Web context (controllers), required for @Transactional to intercept at the service boundary
• Transactional booking flow — PROPAGATION_REQUIRES_NEW wraps the external GDS FlightCheck call inside its own transaction; SEQUENCE IDs assigned at persist() before flush
• Native-SQL reporting with CSV / Excel export (Apache POI) and date-range filters

• Logback observability — per-request MDC requestId, three named log files routing to business / Sabre-integration / errors

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Stack

Java 17 · Spring 6.1.14 · Hibernate 6.4.4.Final · PostgreSQL 16 · HikariCP · Tomcat 10.1 · Maven multi-module WAR · Jackson · Apache POI · Logback · Bootstrap 3 / jQuery / Handlebars

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Run It

Requires Docker. See HOW-TO-RUN.md for the full API reference.

# 1 — PostgreSQL
docker run -d --name mini-midoffice-db -p 5432:5432 `
  -e POSTGRES_PASSWORD=miniumbrella -e POSTGRES_DB=miniumbrella `
  postgres:16

# 2 — Build  (adjust volume path to your checkout location)
docker run --rm `
  -v "C:/workspace/mini-midoffice:/workspace" `
  -v "$env:USERPROFILE/.m2:/root/.m2" `
  -w /workspace `
  maven:3.9.6-eclipse-temurin-17 `
  mvn clean package -DskipTests --no-transfer-progress

# 3 — Run
docker run -d --name mini-midoffice-app -p 8080:8080 `
  -e JAVA_OPTS="-Ddb.url=jdbc:postgresql://host.docker.internal:5432/miniumbrella -Ddb.username=postgres -Ddb.password=miniumbrella" `
  -v "C:/workspace/mini-midoffice/mini-midoffice-web/target/mini-midoffice-web-1.0.0-SNAPSHOT.war:/usr/local/tomcat/webapps/ROOT.war:ro" `
  tomcat:10.1-jdk17

App at http://localhost:8080 · API at http://localhost:8080/api/

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Project Structure

mini-midoffice/
├── mini-midoffice-domain/        JPA entities, enums, domain exceptions
├── mini-midoffice-integration/   Sabre GDS adapters, OAuth2, HTTP client
├── mini-midoffice-persistence/   Hibernate DAOs, JDBC reporting, schema SQL
├── mini-midoffice-service/       Business logic, BookingServiceImpl (TransactionTemplate)
└── mini-midoffice-web/           Spring MVC controllers, filters, SPA, web.xml