GH-10083: Add Nullability to support.management

spring-integration-core/src/main/java/org/springframework/integration/dsl/RouterSpec.java

@@ -40,6 +40,7 @@
  *
  * @author Artem Bilan
  * @author Gary Russell
+ * @author Glenn Renfro
  *
  * @since 5.0
  */
@@ -254,6 +255,7 @@ void addMapping(Object key, NamedComponent channel) {
 		}
 
 		@Override
+		@SuppressWarnings("NullAway") // Performance
 		protected void onInit() {
 			super.onInit();
 			ConversionService conversionService = getConversionService();
@@ -273,7 +275,6 @@ else if (conversionService.canConvert(key.getClass(), String.class)) {
 					throw new MessagingException("Unsupported channel mapping type for router ["
 							+ key.getClass() + "]");
 				}
-
 				this.router.setChannelMapping(channelKey, entry.getValue().getComponentName());
 			}
 		}

spring-integration-core/src/main/java/org/springframework/integration/support/management/ControlBusCommandRegistry.java

@@ -300,6 +300,7 @@ public static final class CommandMethod {
 
 		private final Class<?>[] parameterTypes;
 
+		@SuppressWarnings("NullAway.Init")
 		private String description;
 
 		private CommandMethod(String beanName, String methodName, Class<?>[] parameterTypes) {

spring-integration-core/src/main/java/org/springframework/integration/support/management/package-info.java

@@ -1,4 +1,5 @@
 /**
  * Provides classes related to management support.
  */
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.support.management;