From ce8d923382145d651780aa5e480c294dcc9ce6b3 Mon Sep 17 00:00:00 2001
From: Oliver Gierke <ogierke@pivotal.io>
Date: Thu, 26 Oct 2017 23:29:02 +0200
Subject: [PATCH] DATACMNS-1180 - Fixed accessor lookup for generic properties.

In AbstractPersistentProperty, we now resolve the potentially generic return and parameter types of getters and setters.
---
 .../model/AbstractPersistentProperty.java     | 21 +++++++++++++------
 .../AbstractPersistentPropertyUnitTests.java  | 20 ++++++++++++++++++
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/src/main/java/org/springframework/data/mapping/model/AbstractPersistentProperty.java b/src/main/java/org/springframework/data/mapping/model/AbstractPersistentProperty.java
index 9e64ebfa8..e45d47b6b 100644
--- a/src/main/java/org/springframework/data/mapping/model/AbstractPersistentProperty.java
+++ b/src/main/java/org/springframework/data/mapping/model/AbstractPersistentProperty.java
@@ -61,15 +61,15 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 		Assert.notNull(simpleTypeHolder, "SimpleTypeHolder must not be null!");
 		Assert.notNull(owner, "Owner entity must not be null!");
 
+		this.propertyDescriptor = propertyDescriptor;
+		this.field = field;
+		this.owner = owner;
+		this.simpleTypeHolder = simpleTypeHolder;
 		this.name = field == null ? propertyDescriptor.getName() : field.getName();
 		this.information = owner.getTypeInformation().getProperty(this.name);
 		this.rawType = this.information != null ? information.getType()
 				: field == null ? propertyDescriptor.getPropertyType() : field.getType();
-		this.propertyDescriptor = propertyDescriptor;
-		this.field = field;
 		this.association = isAssociation() ? createAssociation() : null;
-		this.owner = owner;
-		this.simpleTypeHolder = simpleTypeHolder;
 		this.hashCode = this.field == null ? this.propertyDescriptor.hashCode() : this.field.hashCode();
 	}
 
@@ -163,7 +163,11 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 			return null;
 		}
 
-		return rawType.isAssignableFrom(getter.getReturnType()) ? getter : null;
+		Class<?> returnType = owner.getTypeInformation() //
+				.getReturnType(getter) //
+				.getType();
+
+		return rawType.isAssignableFrom(returnType) ? getter : null;
 	}
 
 	/* 
@@ -183,7 +187,12 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 			return null;
 		}
 
-		return setter.getParameterTypes()[0].isAssignableFrom(rawType) ? setter : null;
+		Class<?> parameterType = owner.getTypeInformation() //
+				.getParameterTypes(setter) //
+				.get(0) //
+				.getType();
+
+		return parameterType.isAssignableFrom(rawType) ? setter : null;
 	}
 
 	/*
diff --git a/src/test/java/org/springframework/data/mapping/model/AbstractPersistentPropertyUnitTests.java b/src/test/java/org/springframework/data/mapping/model/AbstractPersistentPropertyUnitTests.java
index 65c8b494f..dac2eb2ac 100644
--- a/src/test/java/org/springframework/data/mapping/model/AbstractPersistentPropertyUnitTests.java
+++ b/src/test/java/org/springframework/data/mapping/model/AbstractPersistentPropertyUnitTests.java
@@ -18,6 +18,9 @@ package org.springframework.data.mapping.model;
 import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
 
+import lombok.Getter;
+import lombok.Setter;
+
 import java.beans.BeanInfo;
 import java.beans.IntrospectionException;
 import java.beans.Introspector;
@@ -208,6 +211,15 @@ public class AbstractPersistentPropertyUnitTests {
 		assertThat(property.getRawType(), is(typeCompatibleWith(String.class)));
 	}
 
+	@Test // DATACMNS-1180
+	public void returnsAccessorsForGenericReturnType() {
+
+		SamplePersistentProperty property = getProperty(ConcreteGetter.class, "genericField");
+
+		assertThat(property.getSetter(), is(notNullValue()));
+		assertThat(property.getGetter(), is(notNullValue()));
+	}
+
 	private <T> SamplePersistentProperty getProperty(Class<T> type, String name) {
 		return getProperty(type, name, getPropertyDescriptor(type, name));
 	}
@@ -253,6 +265,14 @@ public class AbstractPersistentPropertyUnitTests {
 
 	}
 
+	@Getter
+	@Setter
+	class GenericGetter<T> {
+		T genericField;
+	}
+
+	class ConcreteGetter extends GenericGetter<String> {}
+
 	@SuppressWarnings("serial")
 	class TestClassSet extends TreeSet<Object> {}