CachedIntrospectionResults explicitly introspects implemented interfaces (for Java 8 default methods)

Issue: SPR-14198

spring-beans/src/main/java/org/springframework/beans/CachedIntrospectionResults.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -303,6 +303,24 @@ public class CachedIntrospectionResults {
 				this.propertyDescriptorCache.put(pd.getName(), pd);
 			}
 
+			// Explicitly check implemented interfaces for setter/getter methods as well,
+			// in particular for Java 8 default methods...
+			Class<?> clazz = beanClass;
+			while (clazz != null) {
+				Class<?>[] ifcs = clazz.getInterfaces();
+				for (Class<?> ifc : ifcs) {
+					BeanInfo ifcInfo = Introspector.getBeanInfo(ifc, Introspector.IGNORE_ALL_BEANINFO);
+					PropertyDescriptor[] ifcPds = ifcInfo.getPropertyDescriptors();
+					for (PropertyDescriptor pd : ifcPds) {
+						if (!this.propertyDescriptorCache.containsKey(pd.getName())) {
+							pd = buildGenericTypeAwarePropertyDescriptor(beanClass, pd);
+							this.propertyDescriptorCache.put(pd.getName(), pd);
+						}
+					}
+				}
+				clazz = clazz.getSuperclass();
+			}
+
 			this.typeDescriptorCache = new ConcurrentReferenceHashMap<PropertyDescriptor, TypeDescriptor>();
 		}
 		catch (IntrospectionException ex) {

spring-beans/src/test/java/org/springframework/beans/BeanWrapperTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -61,6 +61,14 @@ public class BeanWrapperTests extends AbstractPropertyAccessorTests {
 		assertTrue("Set name to tom", target.getName().equals("tom"));
 	}
 
+	@Test
+	public void aliasedSetterThroughDefaultMethod() {
+		GetterBean target = new GetterBean();
+		BeanWrapper accessor = createAccessor(target);
+		accessor.setPropertyValue("aliasedName", "tom");
+		assertTrue("Set name to tom", target.getAliasedName().equals("tom"));
+	}
+
 	@Test
 	public void setValidAndInvalidPropertyValuesShouldContainExceptionDetails() {
 		TestBean target = new TestBean();
@@ -196,7 +204,24 @@ public class BeanWrapperTests extends AbstractPropertyAccessorTests {
 
 
 	@SuppressWarnings("unused")
-	private static class GetterBean {
+	private interface AliasedProperty {
+
+		default void setAliasedName(String name) {
+			setName(name);
+		}
+
+		default String getAliasedName() {
+			return getName();
+		}
+
+		void setName(String name);
+
+		String getName();
+	}
+
+
+	@SuppressWarnings("unused")
+	private static class GetterBean implements AliasedProperty {
 
 		private String name;
 
@@ -212,6 +237,7 @@ public class BeanWrapperTests extends AbstractPropertyAccessorTests {
 		}
 	}
 
+
 	@SuppressWarnings("unused")
 	private static class IntelliBean {