Remove object wrappers in Kotlin extensions

This commit also improve significantly Kotlin extensions
documentation.

Issue: SPR-15127

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

@@ -0,0 +1,60 @@
+package org.springframework.beans.factory
+
+import kotlin.reflect.KClass
+
+
+/**
+ * Extension for [BeanFactory.getBean] providing a [KClass] based variant.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+fun <T : Any> BeanFactory.getBean(requiredType: KClass<T>) = getBean(requiredType.java)
+
+/**
+ * Extension for [BeanFactory.getBean] providing a `getBean<Foo>()` variant.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+inline fun <reified T : Any> BeanFactory.getBean() = getBean(T::class.java)
+
+/**
+ * Extension for [BeanFactory.getBean] providing a [KClass] based variant.
+ *
+ * @see BeanFactory.getBean(String, Class<T>)
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+fun <T : Any> BeanFactory.getBean(name: String, requiredType: KClass<T>) =
+		getBean(name, requiredType.java)
+
+/**
+ * Extension for [BeanFactory.getBean] providing a `getBean<Foo>("foo")` variant.
+ *
+ * @see BeanFactory.getBean(String, Class<T>)
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+inline fun <reified T : Any> BeanFactory.getBean(name: String) =
+		getBean(name, T::class.java)
+
+/**
+ * Extension for [BeanFactory.getBean] providing a [KClass] based variant.
+ *
+ * @see BeanFactory.getBean(Class<T>, Object...)
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+fun <T : Any> BeanFactory.getBean(requiredType: KClass<T>, vararg args:Any) =
+		getBean(requiredType.java, *args)
+
+/**
+ * Extension for [BeanFactory.getBean] providing a `getBean<Foo>(arg1, arg2)` variant.
+ *
+ * @see BeanFactory.getBean(Class<T>, Object...)
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+inline fun <reified T : Any> BeanFactory.getBean(vararg args:Any) =
+		getBean(T::class.java, *args)

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

@@ -0,0 +1,97 @@
+package org.springframework.beans.factory
+
+import kotlin.reflect.KClass
+
+
+/**
+ * Extension for [ListableBeanFactory.getBeanNamesForType] providing a [KClass] based variant.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+fun <T : Any> ListableBeanFactory.getBeanNamesForType(type: KClass<T>,
+		includeNonSingletons: Boolean = true, allowEagerInit: Boolean = true) =
+				getBeanNamesForType(type.java, includeNonSingletons, allowEagerInit)
+
+/**
+ * Extension for [ListableBeanFactory.getBeanNamesForType] providing a `getBeanNamesForType<Foo>()` variant.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+inline fun <reified T : Any> ListableBeanFactory.getBeanNamesForType(includeNonSingletons: Boolean = true, allowEagerInit: Boolean = true) =
+				getBeanNamesForType(T::class.java, includeNonSingletons, allowEagerInit)
+
+/**
+ * Extension for [ListableBeanFactory.getBeansOfType] providing a [KClass] based variant.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+fun <T : Any> ListableBeanFactory.getBeansOfType(type: KClass<T>,
+		includeNonSingletons: Boolean = true, allowEagerInit: Boolean = true) =
+				getBeansOfType(type.java, includeNonSingletons, allowEagerInit)
+
+/**
+ * Extension for [ListableBeanFactory.getBeansOfType] providing a `getBeansOfType<Foo>()` variant.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+inline fun <reified T : Any> ListableBeanFactory.getBeansOfType(includeNonSingletons: Boolean = true, allowEagerInit: Boolean = true) =
+				getBeansOfType(T::class.java, includeNonSingletons, allowEagerInit)
+
+/**
+ * Extension for [ListableBeanFactory.getBeanNamesForAnnotation] providing a [KClass] based variant.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+fun <T : Annotation> ListableBeanFactory.getBeanNamesForAnnotation(type: KClass<T>) =
+		getBeanNamesForAnnotation(type.java)
+
+/**
+ * Extension for [ListableBeanFactory.getBeanNamesForAnnotation] providing a `getBeansOfType<Foo>()` variant.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+inline fun <reified T : Annotation> ListableBeanFactory.getBeanNamesForAnnotation() =
+		getBeanNamesForAnnotation(T::class.java)
+
+/**
+ * Extension for [ListableBeanFactory.getBeansWithAnnotation] providing a [KClass] based variant.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+fun <T : Annotation> ListableBeanFactory.getBeansWithAnnotation(type: KClass<T>) =
+		getBeansWithAnnotation(type.java)
+
+/**
+ * Extension for [ListableBeanFactory.getBeansWithAnnotation] providing a `getBeansWithAnnotation<Foo>()` variant.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+inline fun <reified T : Annotation> ListableBeanFactory.getBeansWithAnnotation() =
+		getBeansWithAnnotation(T::class.java)
+
+/**
+ * Extension for [ListableBeanFactory.findAnnotationOnBean] providing a [KClass] based variant.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+fun <T : Annotation> ListableBeanFactory.findAnnotationOnBean(beanName:String, type: KClass<T>) =
+		findAnnotationOnBean(beanName, type.java)
+
+/**
+ * Extension for [ListableBeanFactory.findAnnotationOnBean] providing a `findAnnotationOnBean<Foo>("foo")` variant.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+inline fun <reified T : Annotation> ListableBeanFactory.findAnnotationOnBean(beanName:String) =
+		findAnnotationOnBean(beanName, T::class.java)
+

spring-context/src/main/kotlin/org/springframework/context/annotation/AnnotationConfigApplicationContextExtensions.kt

@@ -0,0 +1,11 @@
+package org.springframework.context.annotation
+
+/**
+ * Extension for [AnnotationConfigApplicationContext] allowing
+ * `AnnotationConfigApplicationContext { ... }` style initialization.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.0
+ */
+fun AnnotationConfigApplicationContext(configure: AnnotationConfigApplicationContext.()->Unit) =
+		AnnotationConfigApplicationContext().apply(configure)