Add support for target type to BeanRegistry

Closes gh-34560

spring-beans/src/main/java/org/springframework/beans/factory/BeanRegistry.java

@@ -24,6 +24,8 @@ import org.springframework.beans.BeanUtils;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.support.AbstractBeanDefinition;
+import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.core.ResolvableType;
 import org.springframework.core.env.Environment;
 
@@ -149,6 +151,20 @@ public interface BeanRegistry {
 		 * @see AbstractBeanDefinition#setInstanceSupplier(Supplier)
 		 */
 		Spec<T> supplier(Function<SupplierContext, T> supplier);
+
+		/**
+		 * Set a generics-containing target type of this bean.
+		 * @see #targetType(ResolvableType)
+		 * @see RootBeanDefinition#setTargetType(ResolvableType)
+		 */
+		Spec<T> targetType(ParameterizedTypeReference<? extends T> type);
+
+		/**
+		 * Set a generics-containing target type of this bean.
+		 * @see #targetType(ParameterizedTypeReference)
+		 * @see RootBeanDefinition#setTargetType(ResolvableType)
+		 */
+		Spec<T> targetType(ResolvableType type);
 	}
 
 	/**

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

@@ -30,6 +30,7 @@ import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.BeanDefinitionCustomizer;
+import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.core.ResolvableType;
 import org.springframework.util.MultiValueMap;
 
@@ -211,6 +212,18 @@ public class BeanRegistryAdapter implements BeanRegistry {
 					supplier.apply(new SupplierContextAdapter(this.beanFactory)));
 			return this;
 		}
+
+		@Override
+		public Spec<T> targetType(ParameterizedTypeReference<? extends T> targetType) {
+			this.beanDefinition.setTargetType(ResolvableType.forType(targetType));
+			return this;
+		}
+
+		@Override
+		public Spec<T> targetType(ResolvableType targetType) {
+			this.beanDefinition.setTargetType(targetType);
+			return this;
+		}
 	}
 
 	static class SupplierContextAdapter implements SupplierContext {

spring-beans/src/main/kotlin/org/springframework/beans/factory/BeanRegistrarDsl.kt

@@ -122,6 +122,10 @@ open class BeanRegistrarDsl(private val init: BeanRegistrarDsl.() -> Unit): Bean
 			if (prototype) {
 				it.prototype()
 			}
+			val resolvableType = ResolvableType.forType(object: ParameterizedTypeReference<T>() {});
+			if (resolvableType.hasGenerics()) {
+				it.targetType(resolvableType)
+			}
 		}
 		registry.registerBean(name, T::class.java, customizer)
 	}
@@ -184,6 +188,10 @@ open class BeanRegistrarDsl(private val init: BeanRegistrarDsl.() -> Unit): Bean
 			if (prototype) {
 				it.prototype()
 			}
+			val resolvableType = ResolvableType.forType(object: ParameterizedTypeReference<T>() {});
+			if (resolvableType.hasGenerics()) {
+				it.targetType(resolvableType)
+			}
 		}
 		return registry.registerBean(T::class.java, customizer)
 	}
@@ -250,6 +258,10 @@ open class BeanRegistrarDsl(private val init: BeanRegistrarDsl.() -> Unit): Bean
 			it.supplier {
 				SupplierContextDsl<T>(it).supplier()
 			}
+			val resolvableType = ResolvableType.forType(object: ParameterizedTypeReference<T>() {});
+			if (resolvableType.hasGenerics()) {
+				it.targetType(resolvableType)
+			}
 		}
 		registry.registerBean(name, T::class.java, customizer)
 	}
@@ -314,6 +326,10 @@ open class BeanRegistrarDsl(private val init: BeanRegistrarDsl.() -> Unit): Bean
 			it.supplier {
 				SupplierContextDsl<T>(it).supplier()
 			}
+			val resolvableType = ResolvableType.forType(object: ParameterizedTypeReference<T>() {});
+			if (resolvableType.hasGenerics()) {
+				it.targetType(resolvableType)
+			}
 		}
 		return registry.registerBean(T::class.java, customizer)
 	}