Performance improvements to NamedContextFactory. (#826)

Fixes gh-825

Author: spencergibb

spring-cloud-context/src/main/java/org/springframework/cloud/context/named/NamedContextFactory.java

@@ -27,6 +27,7 @@
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanFactoryUtils;
 import org.springframework.beans.factory.DisposableBean;
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration;
 import org.springframework.context.ApplicationContext;
@@ -143,10 +144,12 @@ protected String generateDisplayName(String name) {
 
 	public <T> T getInstance(String name, Class<T> type) {
 		AnnotationConfigApplicationContext context = getContext(name);
-		if (BeanFactoryUtils.beanNamesForTypeIncludingAncestors(context,
-				type).length > 0) {
+		try {
 			return context.getBean(type);
 		}
+		catch (NoSuchBeanDefinitionException e) {
+			// ignore
+		}
 		return null;
 	}
 
@@ -181,11 +184,8 @@ public <T> T getInstance(String name, ResolvableType type) {
 
 	public <T> Map<String, T> getInstances(String name, Class<T> type) {
 		AnnotationConfigApplicationContext context = getContext(name);
-		if (BeanFactoryUtils.beanNamesForTypeIncludingAncestors(context,
-				type).length > 0) {
-			return BeanFactoryUtils.beansOfTypeIncludingAncestors(context, type);
-		}
-		return null;
+
+		return BeanFactoryUtils.beansOfTypeIncludingAncestors(context, type);
 	}
 
 	/**

spring-cloud-context/src/test/java/org/springframework/cloud/context/named/NamedContextFactoryTests.java

@@ -54,6 +54,18 @@ public void testChildContexts() {
 		Bar foobar = factory.getInstance("foo", Bar.class);
 		then(foobar).as("bar was not null").isNull();
 
+		Baz fooBaz = factory.getInstance("foo", Baz.class);
+		then(fooBaz).as("fooBaz was null").isNotNull();
+
+		Object fooContainerFoo = factory.getInstance("foo", Container.class, Foo.class);
+		then(fooContainerFoo).as("fooContainerFoo was null").isNotNull();
+
+		Object fooContainerBar = factory.getInstance("foo", Container.class, Bar.class);
+		then(fooContainerBar).as("fooContainerBar was not null").isNull();
+
+		Object barContainerBar = factory.getInstance("bar", Container.class, Bar.class);
+		then(barContainerBar).as("barContainerBar was null").isNotNull();
+
 		Map<String, Baz> fooBazes = factory.getInstances("foo", Baz.class);
 		then(fooBazes).as("fooBazes was null").isNotNull();
 		then(fooBazes.size()).as("fooBazes size was wrong").isEqualTo(1);
@@ -146,6 +158,11 @@ Foo foo() {
 			return new Foo();
 		}
 
+		@Bean
+		Container<Foo> fooContainer() {
+			return new Container<>(new Foo());
+		}
+
 	}
 
 	static class Foo {
@@ -164,10 +181,29 @@ Baz baz2() {
 			return new Baz();
 		}
 
+		@Bean
+		Container<Bar> barContainer() {
+			return new Container<>(new Bar());
+		}
+
 	}
 
 	static class Bar {
 
 	}
 
+	static class Container<T> {
+
+		private final T item;
+
+		Container(T item) {
+			this.item = item;
+		}
+
+		public T getItem() {
+			return this.item;
+		}
+
+	}
+
 }