Add multi-datasource module: two databases with per-database DataSource, Flyway, EntityManagerFactory and transaction manager on Boot 4.1

Working setup plus one small application per way of getting it wrong (no @Primary, @Primary only, url vs jdbc-url, wrong repository package, Flyway auto-configuration), plain vs named @Transactional, and ChainedTransactionManager with a failing commit. Transcripts are written by the tests. Co-Authored-By: Claude Sonnet 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Uu7q8vPeREyT4218EJPzz1
2026-09-24 09:38:27 +00:00
parent d6b76c57db
commit e59ff029a1
44 changed files with 1465 additions and 0 deletions
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+# What does EntityManagerFactoryBuilder.Builder.packages(Class...) do with the classes it is given?
+
+jar: spring-boot-jpa-4.1.1.jar
+
+--- javap -c: the calls made inside packages(java.lang.Class<?>...) ---
+invokespecial #34                 // Method java/util/HashSet."<init>":()V
+invokestatic  #35                 // Method org/springframework/util/ClassUtils.getPackageName:(Ljava/lang/Class;)Ljava/lang/String;
+invokeinterface #41,  2           // InterfaceMethod java/util/Set.add:(Ljava/lang/Object;)Z
+invokestatic  #47                 // Method org/springframework/util/StringUtils.toStringArray:(Ljava/util/Collection;)[Ljava/lang/String;