GH-3374: Fix scan for BF propagation (#3378)

* GH-3374: Fix scan for BF propagation

Fixes #3374

An internal `ClassPathScanningCandidateComponentProvider` instance in the `IntegrationComponentScanRegistrar`
does not propagate a provided `registry`.

* Implement `getRegistry()` on the internal `ClassPathScanningCandidateComponentProvider` to propagate
a provided into the `registerBeanDefinitions()` a `BeanDefinitionRegistry`
* Add `@Conditional` on some scanned `@MessagingGateway` in the `EnableIntegrationTests`

**Cherry-pick to 5.3.x & 5.2.x**

* * Remove unused import

* Restore `unused` warning on the unused registry arg

Author: artembilan

spring-integration-core/src/main/java/org/springframework/integration/config/IntegrationComponentScanRegistrar.java

@@ -67,8 +67,7 @@
 public class IntegrationComponentScanRegistrar implements ImportBeanDefinitionRegistrar,
 		ResourceLoaderAware, EnvironmentAware {
 
-	private final Map<TypeFilter, ImportBeanDefinitionRegistrar> componentRegistrars =
-			new HashMap<TypeFilter, ImportBeanDefinitionRegistrar>();
+	private final Map<TypeFilter, ImportBeanDefinitionRegistrar> componentRegistrars = new HashMap<>();
 
 	private ResourceLoader resourceLoader;
 
@@ -109,6 +108,11 @@ protected boolean isCandidateComponent(AnnotatedBeanDefinition beanDefinition) {
 								&& !beanDefinition.getMetadata().isAnnotation();
 					}
 
+					@Override
+					protected BeanDefinitionRegistry getRegistry() {
+						return registry;
+					}
+
 				};
 
 		filter(registry, componentScan, scanner); // NOSONAR - never null
@@ -163,7 +167,7 @@ protected Collection<String> getBasePackages(AnnotationMetadata importingClassMe
 			}
 		}
 
-		for (Class<?> clazz : (Class[]) componentScan.get("basePackageClasses")) {
+		for (Class<?> clazz : (Class<?>[]) componentScan.get("basePackageClasses")) {
 			basePackages.add(ClassUtils.getPackageName(clazz));
 		}
 
@@ -216,10 +220,13 @@ private List<TypeFilter> typeFiltersFor(AnnotationAttributes filter, BeanDefinit
 
 	private static void invokeAwareMethods(Object parserStrategyBean, Environment environment,
 			ResourceLoader resourceLoader, BeanDefinitionRegistry registry) {
+
 		if (parserStrategyBean instanceof Aware) {
 			if (parserStrategyBean instanceof BeanClassLoaderAware) {
-				ClassLoader classLoader = (registry instanceof ConfigurableBeanFactory ?
-						((ConfigurableBeanFactory) registry).getBeanClassLoader() : resourceLoader.getClassLoader());
+				ClassLoader classLoader =
+						registry instanceof ConfigurableBeanFactory
+								? ((ConfigurableBeanFactory) registry).getBeanClassLoader()
+								: resourceLoader.getClassLoader();
 				if (classLoader != null) {
 					((BeanClassLoaderAware) parserStrategyBean).setBeanClassLoader(classLoader);
 				}

spring-integration-core/src/test/java/org/springframework/integration/configuration/EnableIntegrationTests.java

@@ -17,7 +17,8 @@
 package org.springframework.integration.configuration;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.fail;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.spy;
@@ -43,6 +44,7 @@
 
 import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.beans.factory.config.AbstractFactoryBean;
@@ -53,12 +55,16 @@
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Condition;
+import org.springframework.context.annotation.ConditionContext;
+import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.ImportResource;
 import org.springframework.context.expression.EnvironmentAccessor;
 import org.springframework.context.expression.MapAccessor;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.core.serializer.support.SerializingConverter;
+import org.springframework.core.type.AnnotatedTypeMetadata;
 import org.springframework.expression.EvaluationContext;
 import org.springframework.expression.spel.support.ReflectivePropertyAccessor;
 import org.springframework.expression.spel.support.StandardEvaluationContext;
@@ -432,15 +438,11 @@ public void testAnnotatedServiceActivator() throws Exception {
 	@Test
 	@DirtiesContext
 	public void testChangePatterns() {
-		try {
-			this.configurer.setComponentNamePatterns(new String[] { "*" });
-			fail("ExpectedException");
-		}
-		catch (IllegalStateException e) {
-			assertThat(e.getMessage()).contains("cannot be changed");
-		}
+		assertThatIllegalStateException()
+				.isThrownBy(() -> this.configurer.setComponentNamePatterns(new String[]{ "*" }))
+				.withMessageContaining("cannot be changed");
 		this.configurer.stop();
-		this.configurer.setComponentNamePatterns(new String[] { "*" });
+		this.configurer.setComponentNamePatterns(new String[]{ "*" });
 		assertThat(TestUtils.getPropertyValue(this.configurer, "componentNamePatterns", String[].class)[0])
 				.isEqualTo("*");
 	}
@@ -468,6 +470,9 @@ public void testMessagingGateway() throws InterruptedException {
 		this.testGateway.sendAsync("foo");
 		assertThat(this.asyncAnnotationProcessLatch.await(1, TimeUnit.SECONDS)).isTrue();
 		assertThat(this.asyncAnnotationProcessThread.get()).isNotSameAs(Thread.currentThread());
+
+		assertThatExceptionOfType(NoSuchBeanDefinitionException.class)
+				.isThrownBy(() -> this.context.getBean(ConditionalGateway.class));
 	}
 
 	/**
@@ -620,14 +625,10 @@ public void testBridgeAnnotations() {
 		assertThat(testMessage).isSameAs(receive);
 		assertThat(this.pollableBridgeOutput.receive(10)).isNull();
 
-		try {
-			this.metaBridgeInput.send(testMessage);
-			fail("MessageDeliveryException expected");
-		}
-		catch (Exception e) {
-			assertThat(e).isInstanceOf(MessageDeliveryException.class);
-			assertThat(e.getMessage()).contains("Dispatcher has no subscribers");
-		}
+
+		assertThatExceptionOfType(MessageDeliveryException.class)
+				.isThrownBy(() -> this.metaBridgeInput.send(testMessage))
+				.withMessageContaining("Dispatcher has no subscribers");
 
 		this.context.getBean("enableIntegrationTests.ContextConfiguration.metaBridgeOutput.bridgeFrom",
 				Lifecycle.class).start();
@@ -652,14 +653,9 @@ public void testBridgeAnnotations() {
 		assertThat(bridgeMessage).isSameAs(receive);
 		assertThat(replyChannel.receive(10)).isNull();
 
-		try {
-			this.myBridgeToInput.send(testMessage);
-			fail("MessageDeliveryException expected");
-		}
-		catch (Exception e) {
-			assertThat(e).isInstanceOf(MessageDeliveryException.class);
-			assertThat(e.getMessage()).contains("Dispatcher has no subscribers");
-		}
+		assertThatExceptionOfType(MessageDeliveryException.class)
+				.isThrownBy(() -> this.myBridgeToInput.send(testMessage))
+				.withMessageContaining("Dispatcher has no subscribers");
 
 		this.context.getBean("enableIntegrationTests.ContextConfiguration.myBridgeToInput.bridgeTo",
 				Lifecycle.class).start();
@@ -762,7 +758,7 @@ public void testIntegrationEvaluationContextCustomization() {
 	private PollableChannel myHandlerSuccessChannel;
 
 	@Test
-	public void testAdvicedServiceActivator() {
+	public void testAdvisedServiceActivator() {
 		Date testDate = new Date();
 
 		this.myHandlerChannel.send(new GenericMessage<>(testDate));
@@ -1411,6 +1407,14 @@ public boolean isRunning() {
 
 	}
 
+	@Conditional(TestCondition.class)
+	@MessagingGateway
+	public interface ConditionalGateway {
+
+		void testGateway(Object payload);
+
+	}
+
 	@TestMessagingGateway
 	public interface TestGateway {
 
@@ -1673,4 +1677,13 @@ public static Object bar(Object o) {
 
 	}
 
+	public static class TestCondition implements Condition {
+
+		@Override
+		public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
+			return context.getBeanFactory().containsBean("DoesNotExist");
+		}
+
+	}
+
 }