Merge pull request #26761 from 1zg12

* pr/26761:
  Polish "Restore customization of PropertyResolver"
  Restore customization of PropertyResolver

Closes gh-26761

Author: snicoll

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -170,10 +170,19 @@ public String getProperty(String key) {
 			}
 		}
 
-		processProperties(beanFactory, new PropertySourcesPropertyResolver(this.propertySources));
+		processProperties(beanFactory, createPropertyResolver(this.propertySources));
 		this.appliedPropertySources = this.propertySources;
 	}
 
+	/**
+	 * Create a {@link ConfigurablePropertyResolver} for the specified property sources.
+	 * @param propertySources the property sources to use
+	 * @since 6.0.12
+	 */
+	protected ConfigurablePropertyResolver createPropertyResolver(MutablePropertySources propertySources){
+		return new PropertySourcesPropertyResolver(propertySources);
+	}
+
 	/**
 	 * Visit each bean definition in the given bean factory and attempt to replace ${...} property
 	 * placeholders with values from the given properties.