From 9137dc7c70ebcc957926cf0dc94b251c24a6b21d Mon Sep 17 00:00:00 2001
From: Oliver Gierke <ogierke@pivotal.io>
Date: Fri, 23 Dec 2016 12:53:36 +0100
Subject: [PATCH] DATACMNS-967 - Getters that are default methods are not
 considered projection input properties anymore.

We now exclude getter methods that are default methods from the consideration which properties of a projection interface are considered input properties in the first place.

Unfortunately no tests for this one as we can't declare default methods in our codebase requiring JDK 6 compatibility.
---
 .../DefaultProjectionInformation.java         | 37 ++++++++++++++++++-
 .../SpelAwareProxyProjectionFactory.java      |  4 ++
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/src/main/java/org/springframework/data/projection/DefaultProjectionInformation.java b/src/main/java/org/springframework/data/projection/DefaultProjectionInformation.java
index 4cb6adb28..80c345301 100644
--- a/src/main/java/org/springframework/data/projection/DefaultProjectionInformation.java
+++ b/src/main/java/org/springframework/data/projection/DefaultProjectionInformation.java
@@ -16,11 +16,12 @@
 package org.springframework.data.projection;
 
 import java.beans.PropertyDescriptor;
+import java.lang.reflect.Method;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 
 import org.springframework.beans.BeanUtils;
+import org.springframework.data.util.ReflectionUtils;
 import org.springframework.util.Assert;
 
 /**
@@ -104,7 +105,7 @@ class DefaultProjectionInformation implements ProjectionInformation {
 	private static List<PropertyDescriptor> collectDescriptors(Class<?> type) {
 
 		List<PropertyDescriptor> result = new ArrayList<PropertyDescriptor>();
-		result.addAll(Arrays.asList(BeanUtils.getPropertyDescriptors(type)));
+		result.addAll(filterDefaultMethods(BeanUtils.getPropertyDescriptors(type)));
 
 		for (Class<?> interfaze : type.getInterfaces()) {
 			result.addAll(collectDescriptors(interfaze));
@@ -112,4 +113,36 @@ class DefaultProjectionInformation implements ProjectionInformation {
 
 		return result;
 	}
+
+	/**
+	 * Returns all {@link PropertyDescriptor}s that don't have a Java 8 default method as getter.
+	 * 
+	 * @param descriptors must not be {@literal null}.
+	 * @return
+	 */
+	private static List<PropertyDescriptor> filterDefaultMethods(PropertyDescriptor[] descriptors) {
+
+		List<PropertyDescriptor> result = new ArrayList<PropertyDescriptor>(descriptors.length);
+
+		for (PropertyDescriptor descriptor : descriptors) {
+			if (!hasDefaultGetter(descriptor)) {
+				result.add(descriptor);
+			}
+		}
+
+		return result;
+	}
+
+	/**
+	 * Returns whether the given {@link PropertyDescriptor} has a getter that is a Java 8 default method.
+	 * 
+	 * @param descriptor must not be {@literal null}.
+	 * @return
+	 */
+	private static boolean hasDefaultGetter(PropertyDescriptor descriptor) {
+
+		Method method = descriptor.getReadMethod();
+
+		return method == null ? false : ReflectionUtils.isDefaultMethod(method);
+	}
 }
diff --git a/src/main/java/org/springframework/data/projection/SpelAwareProxyProjectionFactory.java b/src/main/java/org/springframework/data/projection/SpelAwareProxyProjectionFactory.java
index 91fa404c5..5493d5e4d 100644
--- a/src/main/java/org/springframework/data/projection/SpelAwareProxyProjectionFactory.java
+++ b/src/main/java/org/springframework/data/projection/SpelAwareProxyProjectionFactory.java
@@ -96,6 +96,10 @@ public class SpelAwareProxyProjectionFactory extends ProxyProjectionFactory impl
 			@Override
 			protected boolean isInputProperty(PropertyDescriptor descriptor) {
 
+				if (!super.isInputProperty(descriptor)) {
+					return false;
+				}
+
 				Method readMethod = descriptor.getReadMethod();
 
 				if (readMethod == null) {