ReflectivePropertyAccessor uses interface methods if possible

Closes gh-22242

spring-expression/src/main/java/org/springframework/expression/spel/support/ReflectivePropertyAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -41,6 +41,7 @@
 import org.springframework.expression.spel.CompilablePropertyAccessor;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
 
@@ -413,7 +414,7 @@ private Method findMethodForProperty(String[] methodSuffixes, String prefix, Cla
 						method.getParameterCount() == numberOfParams &&
 						(!mustBeStatic || Modifier.isStatic(method.getModifiers())) &&
 						(requiredReturnTypes.isEmpty() || requiredReturnTypes.contains(method.getReturnType()))) {
-					return method;
+					return ClassUtils.getInterfaceMethodIfPossible(method);
 				}
 			}
 		}