Code generation not applying shortcut if the target method is ambiguous

Closes spring-projectsgh-29278

spring-beans/src/main/java/org/springframework/beans/factory/aot/InstanceSupplierCodeGenerator.java

@@ -220,7 +220,9 @@ private CodeBlock generateCodeForAccessibleFactoryMethod(String beanName,
 			CodeBlock.Builder code = CodeBlock.builder();
 			code.add("$T.<$T>forFactoryMethod($T.class, $S)", BeanInstanceSupplier.class,
 					suppliedType, declaringClass, factoryMethod.getName());
-			code.add(".withGenerator($T::$L)", declaringClass, factoryMethod.getName());
+			if (!isFactoryMethodAmbiguous(factoryMethod.getName(), declaringClass)) {
+				code.add(".withGenerator($T::$L)", declaringClass, factoryMethod.getName());
+			}
 			return code.build();
 		}
 
@@ -229,6 +231,12 @@ private CodeBlock generateCodeForAccessibleFactoryMethod(String beanName,
 						declaringClass, dependsOnBean, PRIVATE_STATIC));
 		return generateReturnStatement(getInstanceMethod);
 	}
+	private boolean isFactoryMethodAmbiguous(String methodName, Class<?> declaringClass) {
+		long count = Arrays.stream(declaringClass.getMethods())
+				.filter(method -> method.getName().equals(methodName))
+				.count();
+		return count > 1;
+	}
 
 	private CodeBlock generateCodeForInaccessibleFactoryMethod(
 			String beanName, Method factoryMethod, Class<?> declaringClass) {

spring-beans/src/test/java/org/springframework/beans/factory/aot/BeanDefinitionMethodGeneratorTests.java

@@ -584,6 +584,13 @@ void generateBeanDefinitionMethodWhenBeanIsInJavaxPackage() {
 		testBeanDefinitionMethodInCurrentFile(DocumentBuilderFactory.class, beanDefinition);
 	}
 
+	@Test
+	void generateBeanDefinitionMethodWhenFactoryMethodIsAmbiguous() {
+		RootBeanDefinition beanDefinition = (RootBeanDefinition) BeanDefinitionBuilder
+				.rootBeanDefinition(DocumentBuilderFactory.class).setFactoryMethod("newNSInstance").getBeanDefinition();
+		testBeanDefinitionMethodInCurrentFile(DocumentBuilderFactory.class, beanDefinition);
+	}
+
 	@Test
 	void generateBeanDefinitionMethodWhenBeanIsOfPrimitiveType() {
 		RootBeanDefinition beanDefinition = (RootBeanDefinition) BeanDefinitionBuilder