Add public method to get bean order on DefaultListableBeanFactory

Closes gh-34712

Author: jhoeller

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

@@ -29,6 +29,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Comparator;
 import java.util.IdentityHashMap;
 import java.util.Iterator;
@@ -2315,6 +2316,33 @@ public boolean usesStandardBeanLookup() {
 		return (result instanceof Optional<?> optional ? optional : Optional.ofNullable(result));
 	}
 
+	/**
+	 * Public method to determine the applicable order value for a given bean.
+	 * <p>This variant implicitly obtains a corresponding bean instance from this factory.
+	 * @param beanName the name of the bean
+	 * @return the corresponding order value (default is {@link Ordered#LOWEST_PRECEDENCE})
+	 * @since 7.0
+	 * @see #getOrder(String, Object)
+	 */
+	public int getOrder(String beanName) {
+		return getOrder(beanName, getBean(beanName));
+	}
+
+	/**
+	 * Public method to determine the applicable order value for a given bean.
+	 * @param beanName the name of the bean
+	 * @param beanInstance the bean instance to check
+	 * @return the corresponding order value (default is {@link Ordered#LOWEST_PRECEDENCE})
+	 * @since 7.0
+	 * @see #getOrder(String)
+	 */
+	public int getOrder(String beanName, Object beanInstance) {
+		OrderComparator comparator = (getDependencyComparator() instanceof OrderComparator orderComparator ?
+				orderComparator : OrderComparator.INSTANCE);
+		return comparator.getOrder(beanInstance,
+				new FactoryAwareOrderSourceProvider(Collections.singletonMap(beanInstance, beanName)));
+	}
+
 
 	@Override
 	public String toString() {
@@ -2672,7 +2700,7 @@ public FactoryAwareOrderSourceProvider(Map<Object, String> instancesToBeanNames)
 				return null;
 			}
 			try {
-				RootBeanDefinition beanDefinition = (RootBeanDefinition) getMergedBeanDefinition(beanName);
+				BeanDefinition beanDefinition = getMergedBeanDefinition(beanName);
 				List<Object> sources = new ArrayList<>(3);
 				Object orderAttribute = beanDefinition.getAttribute(AbstractBeanDefinition.ORDER_ATTRIBUTE);
 				if (orderAttribute != null) {
@@ -2684,13 +2712,15 @@ public FactoryAwareOrderSourceProvider(Map<Object, String> instancesToBeanNames)
 								AbstractBeanDefinition.ORDER_ATTRIBUTE + "': " + orderAttribute.getClass().getName());
 					}
 				}
-				Method factoryMethod = beanDefinition.getResolvedFactoryMethod();
-				if (factoryMethod != null) {
-					sources.add(factoryMethod);
-				}
-				Class<?> targetType = beanDefinition.getTargetType();
-				if (targetType != null && targetType != obj.getClass()) {
-					sources.add(targetType);
+				if (beanDefinition instanceof RootBeanDefinition rootBeanDefinition) {
+					Method factoryMethod = rootBeanDefinition.getResolvedFactoryMethod();
+					if (factoryMethod != null) {
+						sources.add(factoryMethod);
+					}
+					Class<?> targetType = rootBeanDefinition.getTargetType();
+					if (targetType != null && targetType != obj.getClass()) {
+						sources.add(targetType);
+					}
 				}
 				return sources.toArray();
 			}

spring-beans/src/test/java/org/springframework/beans/factory/DefaultListableBeanFactoryTests.java

@@ -1542,6 +1542,7 @@ void orderFromAttribute() {
 		bd2.setAttribute(AbstractBeanDefinition.ORDER_ATTRIBUTE, Ordered.HIGHEST_PRECEDENCE);
 		bd2.setScope(BeanDefinition.SCOPE_PROTOTYPE);
 		lbf.registerBeanDefinition("bean2", bd2);
+
 		assertThat(lbf.getBeanProvider(TestBean.class).orderedStream().map(TestBean::getName))
 				.containsExactly("highest", "lowest");
 		assertThat(lbf.getBeanProvider(TestBean.class).orderedStream(clazz -> !DerivedTestBean.class.isAssignableFrom(clazz))
@@ -1550,6 +1551,9 @@ void orderFromAttribute() {
 				.containsExactly("highest", "lowest");
 		assertThat(lbf.getBeanProvider(TestBean.class).orderedStream(ObjectProvider.UNFILTERED, false).map(TestBean::getName))
 				.containsExactly("lowest");
+
+		assertThat(lbf.getOrder("bean1")).isEqualTo(Ordered.LOWEST_PRECEDENCE);
+		assertThat(lbf.getOrder("bean2")).isEqualTo(Ordered.HIGHEST_PRECEDENCE);
 	}
 
 	@Test
@@ -1562,12 +1566,16 @@ void orderFromAttributeOverridesAnnotation() {
 		rbd2.setAttribute(AbstractBeanDefinition.ORDER_ATTRIBUTE, Ordered.LOWEST_PRECEDENCE);
 		rbd2.setScope(BeanDefinition.SCOPE_PROTOTYPE);
 		lbf.registerBeanDefinition("highestPrecedenceFactory", rbd2);
+
 		assertThat(lbf.getBeanProvider(TestBean.class).orderedStream().map(TestBean::getName))
 				.containsExactly("fromLowestPrecedenceTestBeanFactoryBean", "fromHighestPrecedenceTestBeanFactoryBean");
 		assertThat(lbf.getBeanProvider(TestBean.class).orderedStream(ObjectProvider.UNFILTERED).map(TestBean::getName))
 				.containsExactly("fromLowestPrecedenceTestBeanFactoryBean", "fromHighestPrecedenceTestBeanFactoryBean");
 		assertThat(lbf.getBeanProvider(TestBean.class).orderedStream(ObjectProvider.UNFILTERED, false).map(TestBean::getName))
 				.containsExactly("fromLowestPrecedenceTestBeanFactoryBean");
+
+		assertThat(lbf.getOrder("lowestPrecedenceFactory")).isEqualTo(Ordered.HIGHEST_PRECEDENCE);
+		assertThat(lbf.getOrder("highestPrecedenceFactory")).isEqualTo(Ordered.LOWEST_PRECEDENCE);
 	}
 
 	@Test
@@ -1579,6 +1587,7 @@ void invalidOrderAttribute() {
 		GenericBeanDefinition bd2 = new GenericBeanDefinition();
 		bd2.setBeanClass(TestBean.class);
 		lbf.registerBeanDefinition("bean", bd2);
+
 		assertThatIllegalStateException()
 				.isThrownBy(() -> lbf.getBeanProvider(TestBean.class).orderedStream().collect(Collectors.toList()))
 				.withMessageContaining("Invalid value type for attribute");

spring-context/src/test/java/org/springframework/context/annotation/Gh29105Tests.java

@@ -44,6 +44,9 @@ void beanProviderWithParentContextReuseOrder() {
 		Stream<Class<?>> orderedTypes = child.getBeanProvider(MyService.class).orderedStream().map(Object::getClass);
 		assertThat(orderedTypes).containsExactly(CustomService.class, DefaultService.class);
 
+		assertThat(child.getDefaultListableBeanFactory().getOrder("defaultService")).isEqualTo(0);
+		assertThat(child.getDefaultListableBeanFactory().getOrder("customService")).isEqualTo(-1);
+
 		child.close();
 		parent.close();
 	}

spring-core/src/main/java/org/springframework/core/OrderComparator.java

@@ -95,8 +95,9 @@ else if (p2 && !p1) {
 	 * using {@link #findOrder} and falls back to a regular {@link #getOrder(Object)} call.
 	 * @param obj the object to check
 	 * @return the order value, or {@code Ordered.LOWEST_PRECEDENCE} as fallback
+	 * @since 7.0
 	 */
-	private int getOrder(@Nullable Object obj, @Nullable OrderSourceProvider sourceProvider) {
+	public int getOrder(@Nullable Object obj, @Nullable OrderSourceProvider sourceProvider) {
 		Integer order = null;
 		if (obj != null && sourceProvider != null) {
 			Object orderSource = sourceProvider.getOrderSource(obj);