Add support for @Transactional in native images

[mhalbritter]

When running the jdbc-tx sample in sb-3.0.x branch from spring-native, it fails with:

java.lang.IllegalStateException: Failed to execute CommandLineRunner
        at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:769) ~[jdbc-tx:3.0.0-SNAPSHOT]
        at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:750) ~[jdbc-tx:3.0.0-SNAPSHOT]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:318) ~[jdbc-tx:3.0.0-SNAPSHOT]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) ~[jdbc-tx:3.0.0-SNAPSHOT]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1290) ~[jdbc-tx:3.0.0-SNAPSHOT]
        at app.main.SampleApplication.main(SampleApplication.java:23) ~[jdbc-tx:0.0.1.BUILD-SNAPSHOT]
Caused by: java.lang.IllegalArgumentException: Expected transaction
        at org.springframework.util.Assert.isTrue(Assert.java:121) ~[na:na]
        at app.main.Runner.run(Runner.java:53) ~[jdbc-tx:0.0.1.BUILD-SNAPSHOT]
        at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:766) ~[jdbc-tx:3.0.0-SNAPSHOT]
        ... 5 common frames omitted

This is the run method:

	@Override
	@Transactional
	public void run(String... args) throws Exception {
		Assert.isTrue(TransactionSynchronizationManager.isActualTransactionActive(), "Expected transaction");
		try {
			find(1L);
		}
		catch (EmptyResultDataAccessException e) {
			entities.update(ADD_FOO, 1L, "Hello");
		}
	}

I guess that @Transactional doesn't work in native-image.

[sdeleuze]

Related to #28688.

[sdeleuze]

I have improved the support for @Transactional with this commit that makes @Transactional annotated with @Reflective and registers proxy hints for SpringProxy but the jdbc-tx sample here still fails when compiled as a native executable with error creating bean with name 'userEndpoints': Unsatisfied dependency expressed through method 'userEndpoints' parameter 0: No qualifying bean of type 'app.main.Finder<app.main.model.Foo>' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {} error, like if proxied beans can't be injected in native. Notice here we have @Component public class Runner implements CommandLineRunner, Finder<Foo> { ... } that needs to be injected in @Bean public RouterFunction<?> userEndpoints(Finder<Foo> entities) { ... }.This samples works correctly on JVM + AOT so this issue is native specific.

[sdeleuze]

As discussed with @sbrannen, we need to replace the SpringProxyRuntimeHintsRegistrar by an AOT processor that will register dynamically the required proxies like here CommandLineRunner.class, Finder.class, SpringProxy.class, Advised.class, DecoratingProxy.class + reflection entries for proxied interfaces with declared methods.