minor fixes:

fixed method naming
added dirtiesContext annotation to classes that shouldnt share the app context state
using SpringApplication instead of unnecessary SpringApplicationBuilder

spring-amqp-simple/src/main/java/com/baeldung/springamqpsimple/SpringAmqpConfig.java

@@ -35,7 +35,7 @@ public class SpringAmqpConfig {
     }
 
     @Bean
-    SimpleMessageListenerContainer SpringAmqpContainer(ConnectionFactory connectionFactory,
+    SimpleMessageListenerContainer springAmqpContainer(ConnectionFactory connectionFactory,
             MessageListenerAdapter listenerAdapter) {
         SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();
         container.setConnectionFactory(connectionFactory);

spring-amqp-simple/src/main/java/com/baeldung/springamqpsimple/broadcast/BroadcastConfig.java

@@ -61,7 +61,7 @@ public class BroadcastConfig {
     }
 
     @Bean
-    public SimpleRabbitListenerContainerFactory BroadcastContainer(ConnectionFactory connectionFactory, SimpleRabbitListenerContainerFactoryConfigurer configurer) {
+    public SimpleRabbitListenerContainerFactory broadcastContainer(ConnectionFactory connectionFactory, SimpleRabbitListenerContainerFactoryConfigurer configurer) {
         SimpleRabbitListenerContainerFactory factory = new SimpleRabbitListenerContainerFactory();
         configurer.configure(factory, connectionFactory);
         return factory;