Bean definition DSL generates unique bean names for bean classes

Issue: SPR-17242

Author: jhoeller

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

@@ -124,13 +124,29 @@ else if (definition.getFactoryBeanName() != null) {
 			id = generatedBeanName + GENERATED_BEAN_NAME_SEPARATOR + ObjectUtils.getIdentityHexString(definition);
 		}
 		else {
-			// Top-level bean: use plain class name.
-			// Increase counter until the id is unique.
-			int counter = -1;
-			while (counter == -1 || registry.containsBeanDefinition(id)) {
-				counter++;
-				id = generatedBeanName + GENERATED_BEAN_NAME_SEPARATOR + counter;
-			}
+			// Top-level bean: use plain class name with unique suffix if necessary.
+			return uniqueBeanName(generatedBeanName, registry);
+		}
+		return id;
+	}
+
+	/**
+	 * Turn the given bean name into a unique bean name for the given bean factory,
+	 * appending a unique counter as suffix if necessary.
+	 * @param beanName the original bean name
+	 * @param registry the bean factory that the definition is going to be
+	 * registered with (to check for existing bean names)
+	 * @return the unique bean name to use
+	 * @since 5.1
+	 */
+	public static String uniqueBeanName(String beanName, BeanDefinitionRegistry registry) {
+		String id = beanName;
+		int counter = -1;
+
+		// Increase counter until the id is unique.
+		while (counter == -1 || registry.containsBeanDefinition(id)) {
+			counter++;
+			id = beanName + GENERATED_BEAN_NAME_SEPARATOR + counter;
 		}
 		return id;
 	}

spring-context/src/main/kotlin/org/springframework/context/support/BeanDefinitionDsl.kt

@@ -18,6 +18,7 @@ package org.springframework.context.support
 
 import org.springframework.beans.factory.config.BeanDefinitionCustomizer
 import org.springframework.beans.factory.support.AbstractBeanDefinition
+import org.springframework.beans.factory.support.BeanDefinitionReaderUtils
 import org.springframework.context.ApplicationContextInitializer
 import org.springframework.core.env.ConfigurableEnvironment
 import java.util.function.Supplier
@@ -167,11 +168,8 @@ open class BeanDefinitionDsl(private val init: BeanDefinitionDsl.() -> Unit,
 			}
 		}
 
-		when (name) {
-			null -> context.registerBean(T::class.java, customizer)
-			else -> context.registerBean(name, T::class.java, customizer)
-		}
-
+		val beanName = name ?: BeanDefinitionReaderUtils.uniqueBeanName(T::class.java.name, context);
+		context.registerBean(beanName, T::class.java, customizer)
 	}
 
 	/**
@@ -207,13 +205,8 @@ open class BeanDefinitionDsl(private val init: BeanDefinitionDsl.() -> Unit,
 		}
 
 
-		when (name) {
-			null -> context.registerBean(T::class.java,
-					Supplier { function.invoke() }, customizer)
-			else -> context.registerBean(name, T::class.java,
-					Supplier { function.invoke() }, customizer)
-		}
-
+		val beanName = name ?: BeanDefinitionReaderUtils.uniqueBeanName(T::class.java.name, context);
+		context.registerBean(beanName, T::class.java, Supplier { function.invoke() }, customizer)
 	}
 
 	/**

spring-context/src/test/kotlin/org/springframework/context/support/BeanDefinitionDslTests.kt

@@ -34,7 +34,6 @@ class BeanDefinitionDslTests {
 		val beans = beans {
 			bean<Foo>()
 			bean<Bar>("bar", scope = Scope.PROTOTYPE)
-			bean { Baz(ref()) }
 			bean { Baz(ref("bar")) }
 		}
 
@@ -59,7 +58,6 @@ class BeanDefinitionDslTests {
 				}
 			}
 			profile("baz") {
-				bean { Baz(ref()) }
 				bean { Baz(ref("bar")) }
 			}
 		}
@@ -89,7 +87,6 @@ class BeanDefinitionDslTests {
 				bean { FooFoo(env["name"]!!) }
 			}
 			environment( { activeProfiles.contains("baz") } ) {
-				bean { Baz(ref()) }
 				bean { Baz(ref("bar")) }
 			}
 		}
@@ -133,8 +130,8 @@ class BeanDefinitionDslTests {
 	@Test  // SPR-16269
 	fun `Provide access to the context for allowing calling advanced features like getBeansOfType`() {
 		val beans = beans {
-			bean<Foo>("foo1")
-			bean<Foo>("foo2")
+			bean<Foo>()
+			bean<Foo>()
 			bean { BarBar(context.getBeansOfType<Foo>().values) }
 		}