Remove Objects.requireNonNull surround this.handler in the AbstractSimpleMessageHandlerFactoryBean

Remove commented code in AbstractSimpleMessageHandlerFactoryBean.extractTarget
Restructure IntegrationManagementConfigurer.registerComponentGauges so that a NullAway suppresion can be removed from the method
related to: #10083
rebased

Author: cppwfs

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

@@ -26,7 +26,6 @@
 import org.apache.commons.logging.LogFactory;
 import org.jspecify.annotations.Nullable;
 
-import org.springframework.aop.framework.Advised;
 import org.springframework.aop.framework.AopProxyUtils;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanFactory;
@@ -95,7 +94,8 @@ public abstract class AbstractSimpleMessageHandlerFactoryBean<H extends MessageH
 	@SuppressWarnings("NullAway.Init")
 	private String beanName;
 
-	private @Nullable ApplicationEventPublisher applicationEventPublisher;
+	@SuppressWarnings("NullAway.Init")
+	private ApplicationEventPublisher applicationEventPublisher;
 
 	private @Nullable DestinationResolver<MessageChannel> channelResolver;
 
@@ -208,16 +208,16 @@ protected final H createHandlerInternal() {
 			JavaUtils.INSTANCE
 					.acceptIfCondition(this.handler instanceof ApplicationContextAware && this.applicationContext != null,
 							this.applicationContext,
-							context -> ((ApplicationContextAware) Objects.requireNonNull(this.handler)).setApplicationContext(this.applicationContext))
+							context -> ((ApplicationContextAware) this.handler).setApplicationContext(this.applicationContext))
 					.acceptIfCondition(this.handler instanceof BeanFactoryAware && getBeanFactory() != null,
 							getBeanFactory(),
-							factory -> ((BeanFactoryAware) Objects.requireNonNull(this.handler)).setBeanFactory(factory))
+							factory -> ((BeanFactoryAware) this.handler).setBeanFactory(factory))
 					.acceptIfCondition(this.handler instanceof BeanNameAware && this.beanName != null, this.beanName,
-							name -> ((BeanNameAware) Objects.requireNonNull(this.handler)).setBeanName(this.beanName))
+							name -> ((BeanNameAware) this.handler).setBeanName(this.beanName))
 					.acceptIfCondition(this.handler instanceof ApplicationEventPublisherAware
 									&& this.applicationEventPublisher != null,
 							this.applicationEventPublisher,
-							publisher -> ((ApplicationEventPublisherAware) Objects.requireNonNull(Objects.requireNonNull(this.handler)))
+							publisher -> ((ApplicationEventPublisherAware) this.handler)
 									.setApplicationEventPublisher(publisher));
 			configureOutputChannelIfAny();
 			Object actualHandler = extractTarget(this.handler);
@@ -232,7 +232,7 @@ protected final H createHandlerInternal() {
 							this.async,
 							asyncValue -> ((AbstractMessageProducingHandler) handlerToConfigure).setAsync(asyncValue))
 					.acceptIfCondition(this.handler instanceof Orderable && this.order != null,
-							this.order, theOrder -> ((Orderable) Objects.requireNonNull(this.handler)).setOrder(theOrder));
+							this.order, theOrder -> ((Orderable) this.handler).setOrder(theOrder));
 			this.initialized = true;
 		}
 		finally {
@@ -315,14 +315,7 @@ public boolean isSingleton() {
 	}
 
 	private static Object extractTarget(Object object) {
-		if (!(object instanceof Advised)) {
-			return object;
-		}
-		else {
-//			return extractTarget(Objects.requireNonNull(AopProxyUtils.getSingletonTarget(object)));
-			return Objects.requireNonNullElse(AopProxyUtils.getSingletonTarget(object), object);
-
-		}
+		return Objects.requireNonNullElse(AopProxyUtils.getSingletonTarget(object), object);
 	}
 
 }

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

@@ -19,6 +19,7 @@
 import java.lang.reflect.Method;
 
 import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.beans.factory.FactoryBean;
 import org.springframework.beans.factory.InitializingBean;
@@ -42,7 +43,7 @@ public class CorrelationStrategyFactoryBean implements FactoryBean<CorrelationSt
 	@SuppressWarnings("NullAway.Init")
 	private Object target;
 
-	@SuppressWarnings("NullAway.Init")
+	@Nullable
 	private String methodName;
 
 	private CorrelationStrategy strategy =

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

@@ -81,8 +81,7 @@ public class DefaultConfiguringBeanFactoryPostProcessor implements BeanDefinitio
 
 	private static final Set<Integer> REGISTRIES_PROCESSED = new HashSet<>();
 
-	@Nullable
-	private static final Class<?> XPATH_CLASS;
+	private static final @Nullable Class<?> XPATH_CLASS;
 
 	private static final boolean JSON_PATH_PRESENT = ClassUtils.isPresent("com.jayway.jsonpath.JsonPath", null);
 

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

@@ -159,8 +159,9 @@ public void afterSingletonsInstantiated() {
 		Assert.state(MANAGEMENT_CONFIGURER_NAME.equals(this.beanName), getClass().getSimpleName()
 				+ " bean name must be " + MANAGEMENT_CONFIGURER_NAME);
 
-		if (obtainMetricsCaptor() != null) {
-			registerComponentGauges();
+		MetricsCaptor metricsCaptorToUse = obtainMetricsCaptor();
+		if (metricsCaptorToUse != null) {
+			registerComponentGauges(metricsCaptorToUse);
 		}
 
 		setupObservationRegistry();
@@ -185,22 +186,21 @@ private void setupObservationRegistry() {
 		}
 	}
 
-	@SuppressWarnings("NullAway")  // is not called if the metricsCaptor is null in  afterSingletonsInstantiated.
-	private void registerComponentGauges() {
+	private void registerComponentGauges(MetricsCaptor metricsCaptor) {
 		this.gauges.add(
-				this.metricsCaptor.gaugeBuilder("spring.integration.channels", this,
+				metricsCaptor.gaugeBuilder("spring.integration.channels", this,
 								(c) -> this.applicationContext.getBeansOfType(MessageChannel.class).size())
 						.description("The number of message channels")
 						.build());
 
 		this.gauges.add(
-				this.metricsCaptor.gaugeBuilder("spring.integration.handlers", this,
+				metricsCaptor.gaugeBuilder("spring.integration.handlers", this,
 								(c) -> this.applicationContext.getBeansOfType(MessageHandler.class).size())
 						.description("The number of message handlers")
 						.build());
 
 		this.gauges.add(
-				this.metricsCaptor.gaugeBuilder("spring.integration.sources", this,
+				metricsCaptor.gaugeBuilder("spring.integration.sources", this,
 								(c) -> this.applicationContext.getBeansOfType(MessageSource.class).size())
 						.description("The number of message sources")
 						.build());

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

@@ -19,8 +19,6 @@
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 
-import org.jspecify.annotations.Nullable;
-
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.factory.BeanDefinitionStoreException;
 import org.springframework.beans.factory.BeanNameAware;
@@ -44,9 +42,11 @@ public class SpelFunctionFactoryBean implements FactoryBean<Method>, Initializin
 
 	private final String functionMethodSignature;
 
-	private @Nullable String functionName;
+	@SuppressWarnings("NullAway.Init")
+	private String functionName;
 
-	private @Nullable Method method;
+	@SuppressWarnings("NullAway.Init")
+	private Method method;
 
 	public SpelFunctionFactoryBean(Class<?> functionClass, String functionMethodSignature) {
 		this.functionClass = functionClass;
@@ -58,25 +58,26 @@ public void setBeanName(String name) {
 		this.functionName = name;
 	}
 
-	public @Nullable String getFunctionName() {
+	public String getFunctionName() {
 		return this.functionName;
 	}
 
 	@Override
 	public void afterPropertiesSet() {
-		this.method = BeanUtils.resolveSignature(this.functionMethodSignature, this.functionClass);
+		Method method = BeanUtils.resolveSignature(this.functionMethodSignature, this.functionClass);
 
-		if (this.method == null) {
+		if (method == null) {
 			throw new BeanDefinitionStoreException(String.format("No declared method '%s' in class '%s'",
 					this.functionMethodSignature, this.functionClass));
 		}
+		this.method = method;
 		if (!Modifier.isStatic(this.method.getModifiers())) {
 			throw new BeanDefinitionStoreException("SpEL-function method has to be 'static'");
 		}
 	}
 
 	@Override
-	public @Nullable Method getObject() {
+	public Method getObject() {
 		return this.method;
 	}