Polish

See gh-24878

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractBeanFactory.java

@@ -181,7 +181,7 @@ public abstract class AbstractBeanFactory extends FactoryBeanRegistrySupport imp
 			new NamedThreadLocal<>("Prototype beans currently in creation");
 
 	/** Application startup metrics. **/
-	private ApplicationStartup applicationStartup = ApplicationStartup.getDefault();
+	private ApplicationStartup applicationStartup = ApplicationStartup.DEFAULT;
 
 	/**
 	 * Create a new AbstractBeanFactory.

spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassPostProcessor.java

@@ -145,7 +145,7 @@ public class ConfigurationClassPostProcessor implements BeanDefinitionRegistryPo
 	/* Using fully qualified class names as default bean names by default. */
 	private BeanNameGenerator importBeanNameGenerator = IMPORT_BEAN_NAME_GENERATOR;
 
-	private ApplicationStartup applicationStartup = ApplicationStartup.getDefault();
+	private ApplicationStartup applicationStartup = ApplicationStartup.DEFAULT;
 
 
 	@Override

spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java

@@ -231,7 +231,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 	private ApplicationEventMulticaster applicationEventMulticaster;
 
 	/** Application startup metrics. **/
-	private ApplicationStartup applicationStartup = ApplicationStartup.getDefault();
+	private ApplicationStartup applicationStartup = ApplicationStartup.DEFAULT;
 
 	/** Statically specified listeners. */
 	private final Set<ApplicationListener<?>> applicationListeners = new LinkedHashSet<>();

spring-core/src/main/java/org/springframework/core/metrics/ApplicationStartup.java

@@ -28,12 +28,10 @@ package org.springframework.core.metrics;
 public interface ApplicationStartup {
 
 	/**
-	 * Return a default "no op" {@code ApplicationStartup} implementation.
+	 * Default "no op" {@code ApplicationStartup} implementation.
 	 * <p>This variant is designed for minimal overhead and does not record data.
 	 */
-	static ApplicationStartup getDefault() {
-		return new DefaultApplicationStartup();
-	}
+	ApplicationStartup DEFAULT = new DefaultApplicationStartup();
 
 	/**
 	 * Create a new step and marks its beginning.