Fixed detection of setter in case of getter with covariant return type narrowing

Issue: SPR-10995

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -31,32 +31,32 @@ import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
 
 /**
- * Extension of the standard JavaBeans PropertyDescriptor class,
- * overriding {@code getPropertyType()} such that a generically
- * declared type will be resolved against the containing bean class.
+ * Extension of the standard JavaBeans {@link PropertyDescriptor} class,
+ * overriding {@code getPropertyType()} such that a generically declared
+ * type variable will be resolved against the containing bean class.
  *
  * @author Juergen Hoeller
  * @since 2.5.2
  */
 class GenericTypeAwarePropertyDescriptor extends PropertyDescriptor {
 
-	private final Class beanClass;
+	private final Class<?> beanClass;
 
 	private final Method readMethod;
 
 	private final Method writeMethod;
 
-	private final Class propertyEditorClass;
+	private final Class<?> propertyEditorClass;
 
 	private volatile Set<Method> ambiguousWriteMethods;
 
-	private Class propertyType;
+	private Class<?> propertyType;
 
 	private MethodParameter writeMethodParameter;
 
 
-	public GenericTypeAwarePropertyDescriptor(Class beanClass, String propertyName,
-			Method readMethod, Method writeMethod, Class propertyEditorClass)
+	public GenericTypeAwarePropertyDescriptor(Class<?> beanClass, String propertyName,
+			Method readMethod, Method writeMethod, Class<?> propertyEditorClass)
 			throws IntrospectionException {
 
 		super(propertyName, null, null);
@@ -69,8 +69,11 @@ class GenericTypeAwarePropertyDescriptor extends PropertyDescriptor {
 			// Fallback: Original JavaBeans introspection might not have found matching setter
 			// method due to lack of bridge method resolution, in case of the getter using a
 			// covariant return type whereas the setter is defined for the concrete property type.
-			writeMethodToUse = ClassUtils.getMethodIfAvailable(this.beanClass,
-					"set" + StringUtils.capitalize(getName()), readMethodToUse.getReturnType());
+			Method candidate = ClassUtils.getMethodIfAvailable(
+					this.beanClass, "set" + StringUtils.capitalize(getName()), (Class<?>[]) null);
+			if (candidate != null && candidate.getParameterTypes().length == 1) {
+				writeMethodToUse = candidate;
+			}
 		}
 		this.readMethod = readMethodToUse;
 		this.writeMethod = writeMethodToUse;
@@ -118,12 +121,12 @@ class GenericTypeAwarePropertyDescriptor extends PropertyDescriptor {
 	}
 
 	@Override
-	public Class getPropertyEditorClass() {
+	public Class<?> getPropertyEditorClass() {
 		return this.propertyEditorClass;
 	}
 
 	@Override
-	public synchronized Class getPropertyType() {
+	public synchronized Class<?> getPropertyType() {
 		if (this.propertyType == null) {
 			if (this.readMethod != null) {
 				this.propertyType = GenericTypeResolver.resolveReturnType(this.readMethod, this.beanClass);

spring-beans/src/test/java/org/springframework/tests/sample/beans/DerivedTestBean.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -71,6 +71,11 @@ public class DerivedTestBean extends TestBean implements Serializable, BeanNameA
 		setSpouse(new TestBean(name));
 	}
 
+	@Override
+	public TestBean getSpouse() {
+		return (TestBean) super.getSpouse();
+	}
+
 
 	public void initialize() {
 		this.initialized = true;

spring-beans/src/test/resources/org/springframework/beans/factory/xml/collections.xml

@@ -35,11 +35,10 @@
 		</property>
 	</bean>
 
-	<bean id="pJenny" class="org.springframework.tests.sample.beans.TestBean" scope="prototype">
+	<bean id="pJenny" class="org.springframework.tests.sample.beans.DerivedTestBean" scope="prototype">
 		<property name="name"><value>Jenny</value></property>
 		<property name="age"><value>30</value></property>
 		<property name="spouse">
-		<!-- Could use id and href -->
 			<ref local="david"/>
 		</property>
 	</bean>