added first cut of getBean(Class) lookup method

org.springframework.beans/src/main/java/org/springframework/beans/factory/BeanFactory.java

@@ -149,6 +149,15 @@ public interface BeanFactory {
 	 */
 	<T> T getBean(String name, Class<T> requiredType) throws BeansException;
 
+	/**
+	 * Return the bean instance that uniquely matches the given object type, if any.
+	 * @param requiredType type the bean must match; can be an interface or superclass.
+	 * {@literal null} is disallowed.
+	 * @return bean matching required type
+	 * @throws NoSuchBeanDefinitionException if there is not exactly one matching bean found
+	 */
+	<T> T getBean(Class<T> requiredType) throws BeansException;
+
 	/**
 	 * Return an instance, which may be shared or independent, of the specified bean.
 	 * <p>Allows for specifying explicit constructor arguments / factory method arguments,

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

@@ -242,6 +242,19 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 	// Implementation of ListableBeanFactory interface
 	//---------------------------------------------------------------------
 
+	public <T> T getBean(Class<T> requiredType) throws BeansException {
+		String[] beanNames = getBeanNamesForType(requiredType);
+		if (beanNames.length == 1) {
+			return getBean(beanNames[0], requiredType);
+		}
+		else if (beanNames.length == 0 && getParentBeanFactory() != null) {
+			return getParentBeanFactory().getBean(requiredType);
+		}
+		else {
+			throw new NoSuchBeanDefinitionException(requiredType, "expected single bean but found " + beanNames.length);
+		}
+	}
+
 	@Override
 	public boolean containsBeanDefinition(String beanName) {
 		return this.beanDefinitionMap.containsKey(beanName);

org.springframework.beans/src/main/java/org/springframework/beans/factory/support/StaticListableBeanFactory.java

@@ -112,6 +112,16 @@ public class StaticListableBeanFactory implements ListableBeanFactory {
 		return (T) bean;
 	}
 
+	public <T> T getBean(Class<T> requiredType) throws BeansException {
+		String[] beanNames = getBeanNamesForType(requiredType);
+		if (beanNames.length == 1) {
+			return getBean(beanNames[0], requiredType);
+		}
+		else {
+			throw new NoSuchBeanDefinitionException(requiredType, "expected single bean but found " + beanNames.length);
+		}
+	}
+
 	public Object getBean(String name, Object... args) throws BeansException {
 		if (args != null) {
 			throw new UnsupportedOperationException(