Merge pull request #22093 from sdeleuze

* gh-22093:
  Polish "Disable XML reader when spring.xml.ignore is true"
  Disable XML reader when spring.xml.ignore is true

Closes gh-22093

Author: wilkinsona

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/BeanDefinitionLoader.java

@@ -26,12 +26,14 @@
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.factory.BeanDefinitionStoreException;
 import org.springframework.beans.factory.groovy.GroovyBeanDefinitionReader;
+import org.springframework.beans.factory.support.AbstractBeanDefinitionReader;
 import org.springframework.beans.factory.support.BeanDefinitionReader;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.BeanNameGenerator;
 import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
 import org.springframework.context.annotation.AnnotatedBeanDefinitionReader;
 import org.springframework.context.annotation.ClassPathBeanDefinitionScanner;
+import org.springframework.core.SpringProperties;
 import org.springframework.core.env.ConfigurableEnvironment;
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
@@ -53,17 +55,21 @@
  *
  * @author Phillip Webb
  * @author Vladislav Kisel
+ * @author Sebastien Deleuze
  * @see #setBeanNameGenerator(BeanNameGenerator)
  */
 class BeanDefinitionLoader {
 
+	// Static final field to facilitate code removal by Graal
+	private static final boolean XML_ENABLED = !SpringProperties.getFlag("spring.xml.ignore");
+
 	private final Object[] sources;
 
 	private final AnnotatedBeanDefinitionReader annotatedReader;
 
-	private final XmlBeanDefinitionReader xmlReader;
+	private final AbstractBeanDefinitionReader xmlReader;
 
-	private BeanDefinitionReader groovyReader;
+	private final BeanDefinitionReader groovyReader;
 
 	private final ClassPathBeanDefinitionScanner scanner;
 
@@ -80,10 +86,8 @@ class BeanDefinitionLoader {
 		Assert.notEmpty(sources, "Sources must not be empty");
 		this.sources = sources;
 		this.annotatedReader = new AnnotatedBeanDefinitionReader(registry);
-		this.xmlReader = new XmlBeanDefinitionReader(registry);
-		if (isGroovyPresent()) {
-			this.groovyReader = new GroovyBeanDefinitionReader(registry);
-		}
+		this.xmlReader = (XML_ENABLED ? new XmlBeanDefinitionReader(registry) : null);
+		this.groovyReader = (isGroovyPresent() ? new GroovyBeanDefinitionReader(registry) : null);
 		this.scanner = new ClassPathBeanDefinitionScanner(registry);
 		this.scanner.addExcludeFilter(new ClassExcludeFilter(sources));
 	}
@@ -94,8 +98,10 @@ class BeanDefinitionLoader {
 	 */
 	void setBeanNameGenerator(BeanNameGenerator beanNameGenerator) {
 		this.annotatedReader.setBeanNameGenerator(beanNameGenerator);
-		this.xmlReader.setBeanNameGenerator(beanNameGenerator);
 		this.scanner.setBeanNameGenerator(beanNameGenerator);
+		if (this.xmlReader != null) {
+			this.xmlReader.setBeanNameGenerator(beanNameGenerator);
+		}
 	}
 
 	/**
@@ -104,8 +110,10 @@ void setBeanNameGenerator(BeanNameGenerator beanNameGenerator) {
 	 */
 	void setResourceLoader(ResourceLoader resourceLoader) {
 		this.resourceLoader = resourceLoader;
-		this.xmlReader.setResourceLoader(resourceLoader);
 		this.scanner.setResourceLoader(resourceLoader);
+		if (this.xmlReader != null) {
+			this.xmlReader.setResourceLoader(resourceLoader);
+		}
 	}
 
 	/**
@@ -114,8 +122,10 @@ void setResourceLoader(ResourceLoader resourceLoader) {
 	 */
 	void setEnvironment(ConfigurableEnvironment environment) {
 		this.annotatedReader.setEnvironment(environment);
-		this.xmlReader.setEnvironment(environment);
 		this.scanner.setEnvironment(environment);
+		if (this.xmlReader != null) {
+			this.xmlReader.setEnvironment(environment);
+		}
 	}
 
 	/**
@@ -167,6 +177,9 @@ private void load(Resource source) {
 			this.groovyReader.loadBeanDefinitions(source);
 		}
 		else {
+			if (this.xmlReader == null) {
+				throw new BeanDefinitionStoreException("Cannot load XML bean definitions when XML support is disabled");
+			}
 			this.xmlReader.loadBeanDefinitions(source);
 		}
 	}