Narrow the event types ConfigFileApplicationListener supports

See gh-9628

spring-boot/src/main/java/org/springframework/boot/context/config/ConfigFileApplicationListener.java

@@ -46,9 +46,9 @@ import org.springframework.boot.env.EnvironmentPostProcessor;
 import org.springframework.boot.env.PropertySourcesLoader;
 import org.springframework.boot.logging.DeferredLog;
 import org.springframework.context.ApplicationEvent;
-import org.springframework.context.ApplicationListener;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.ConfigurationClassPostProcessor;
+import org.springframework.context.event.SmartApplicationListener;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.AnnotationAwareOrderComparator;
 import org.springframework.core.convert.ConversionService;
@@ -62,6 +62,7 @@ import org.springframework.core.io.DefaultResourceLoader;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.core.io.support.SpringFactoriesLoader;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ResourceUtils;
 import org.springframework.util.StringUtils;
@@ -102,7 +103,7 @@ import org.springframework.validation.BindException;
  * @author Eddú Meléndez
  */
 public class ConfigFileApplicationListener implements EnvironmentPostProcessor,
-		ApplicationListener<ApplicationEvent>, Ordered {
+		SmartApplicationListener, Ordered {
 
 	private static final String DEFAULT_PROPERTIES = "defaultProperties";
 
@@ -276,6 +277,17 @@ public class ConfigFileApplicationListener implements EnvironmentPostProcessor,
 		this.names = names;
 	}
 
+	@Override
+	public boolean supportsEventType(Class<? extends ApplicationEvent> eventType) {
+		return ApplicationEnvironmentPreparedEvent.class.isAssignableFrom(eventType) ||
+				ApplicationPreparedEvent.class.isAssignableFrom(eventType);
+	}
+
+	@Override
+	public boolean supportsSourceType(@Nullable Class<?> aClass) {
+		return true;
+	}
+
 	/**
 	 * {@link BeanFactoryPostProcessor} to re-order our property sources below any
 	 * {@code @PropertySource} items added by the {@link ConfigurationClassPostProcessor}.